diff --git a/builder/nim_builder.rb b/builder/nim_builder.rb
new file mode 100644
index 000000000..e69de29bb
diff --git a/spec/nim/auxiliary/test_utils.nim b/spec/nim/auxiliary/test_utils.nim
index 51fbeebe4..c953de38b 100644
--- a/spec/nim/auxiliary/test_utils.nim
+++ b/spec/nim/auxiliary/test_utils.nim
@@ -4,6 +4,7 @@ export kaitai_struct_nim_runtime.`-`
 
 proc `-`*(n: uint64): int64 = -int64(n - 1) - 1
 
+## Loose equality
 proc `==`*(actual: seq[byte], expected: seq[SomeInteger]|string): bool =
   if actual.len != expected.len:
     return false
@@ -11,3 +12,9 @@ proc `==`*(actual: seq[byte], expected: seq[SomeInteger]|string): bool =
     if actual[i] != expected[i].byte:
       return false
   return true
+
+proc `==`*[S: SomeSignedInt, U: SomeUnsignedInt](x: S, y: U): bool =
+  x == S(y)
+
+proc `==`*[S: SomeSignedInt, U: SomeUnsignedInt](x: U, y: S): bool =
+  S(x) == y
\ No newline at end of file
diff --git a/spec/nim/tbcd_user_type_be.nim b/spec/nim/tbcd_user_type_be.nim
index d0adbd900..c161f3c53 100644
--- a/spec/nim/tbcd_user_type_be.nim
+++ b/spec/nim/tbcd_user_type_be.nim
@@ -6,9 +6,9 @@ import auxiliary/test_utils
 
 let r = BcdUserTypeBe.fromFile("src/bcd_user_type_be.bin")
 
-assert r.ltr.asInt == int(12345678)
-assert r.ltr.asStr == string("12345678")
-assert r.rtl.asInt == int(87654321)
-assert r.rtl.asStr == string("87654321")
-assert r.leadingZeroLtr.asInt == int(123456)
-assert r.leadingZeroLtr.asStr == string("00123456")
+assert r.ltr.asInt == 12345678
+assert r.ltr.asStr == "12345678"
+assert r.rtl.asInt == 87654321
+assert r.rtl.asStr == "87654321"
+assert r.leadingZeroLtr.asInt == 123456
+assert r.leadingZeroLtr.asStr == "00123456"
diff --git a/spec/nim/tbcd_user_type_le.nim b/spec/nim/tbcd_user_type_le.nim
index 09b740974..83c840be3 100644
--- a/spec/nim/tbcd_user_type_le.nim
+++ b/spec/nim/tbcd_user_type_le.nim
@@ -6,9 +6,9 @@ import auxiliary/test_utils
 
 let r = BcdUserTypeLe.fromFile("src/bcd_user_type_le.bin")
 
-assert r.ltr.asInt == int(12345678)
-assert r.ltr.asStr == string("12345678")
-assert r.rtl.asInt == int(87654321)
-assert r.rtl.asStr == string("87654321")
-assert r.leadingZeroLtr.asInt == int(123456)
-assert r.leadingZeroLtr.asStr == string("00123456")
+assert r.ltr.asInt == 12345678
+assert r.ltr.asStr == "12345678"
+assert r.rtl.asInt == 87654321
+assert r.rtl.asStr == "87654321"
+assert r.leadingZeroLtr.asInt == 123456
+assert r.leadingZeroLtr.asStr == "00123456"
diff --git a/spec/nim/tbits_byte_aligned.nim b/spec/nim/tbits_byte_aligned.nim
index 4faa05df9..dc9d56f18 100644
--- a/spec/nim/tbits_byte_aligned.nim
+++ b/spec/nim/tbits_byte_aligned.nim
@@ -6,12 +6,12 @@ import auxiliary/test_utils
 
 let r = BitsByteAligned.fromFile("src/fixed_struct.bin")
 
-assert r.one == uint64(20)
-assert r.byte1 == uint8(65)
-assert r.two == uint64(2)
-assert r.three == bool(false)
-assert r.byte2 == uint8(75)
-assert r.four == uint64(2892)
+assert r.one == 20
+assert r.byte1 == 65
+assert r.two == 2
+assert r.three == false
+assert r.byte2 == 75
+assert r.four == 2892
 assert r.byte3 == @[255'u8]
-assert r.fullByte == uint64(255)
-assert r.byte4 == uint8(80)
+assert r.fullByte == 255
+assert r.byte4 == 80
diff --git a/spec/nim/tbits_seq_endian_combo.nim b/spec/nim/tbits_seq_endian_combo.nim
index 28fa8a852..e379d9ea2 100644
--- a/spec/nim/tbits_seq_endian_combo.nim
+++ b/spec/nim/tbits_seq_endian_combo.nim
@@ -6,11 +6,11 @@ import auxiliary/test_utils
 
 let r = BitsSeqEndianCombo.fromFile("src/process_xor_4.bin")
 
-assert r.be1 == uint64(59)
-assert r.be2 == uint64(187)
-assert r.le3 == uint64(163)
-assert r.be4 == uint64(20)
-assert r.le5 == uint64(10)
-assert r.le6 == uint64(36)
-assert r.le7 == uint64(26)
-assert r.be8 == bool(true)
+assert r.be1 == 59
+assert r.be2 == 187
+assert r.le3 == 163
+assert r.be4 == 20
+assert r.le5 == 10
+assert r.le6 == 36
+assert r.le7 == 26
+assert r.be8 == true
diff --git a/spec/nim/tbits_signed_b32_le.nim b/spec/nim/tbits_signed_b32_le.nim
index 5fd672cbc..afafc2b24 100644
--- a/spec/nim/tbits_signed_b32_le.nim
+++ b/spec/nim/tbits_signed_b32_le.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = BitsSignedB32Le.fromFile("src/bits_signed_b32_le.bin")
 
-assert r.aNum == uint64(0)
-assert r.aBit == bool(true)
-assert r.bNum == uint64(2147483647)
-assert r.bBit == bool(false)
+assert r.aNum == 0
+assert r.aBit == true
+assert r.bNum == 2147483647
+assert r.bBit == false
diff --git a/spec/nim/tbits_signed_b64_le.nim b/spec/nim/tbits_signed_b64_le.nim
index 2f9582954..7bdb8ac25 100644
--- a/spec/nim/tbits_signed_b64_le.nim
+++ b/spec/nim/tbits_signed_b64_le.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = BitsSignedB64Le.fromFile("src/bits_signed_b64_le.bin")
 
-assert r.aNum == uint64(0)
-assert r.aBit == bool(true)
-assert r.bNum == uint64(9223372036854775807'i64)
-assert r.bBit == bool(false)
+assert r.aNum == 0
+assert r.aBit == true
+assert r.bNum == 9223372036854775807'i64
+assert r.bBit == false
diff --git a/spec/nim/tbits_simple.nim b/spec/nim/tbits_simple.nim
index 1fb21c090..912be361a 100644
--- a/spec/nim/tbits_simple.nim
+++ b/spec/nim/tbits_simple.nim
@@ -6,17 +6,17 @@ import auxiliary/test_utils
 
 let r = BitsSimple.fromFile("src/fixed_struct.bin")
 
-assert r.byte1 == uint64(80)
-assert r.byte2 == uint64(65)
-assert r.bitsA == bool(false)
-assert r.bitsB == uint64(4)
-assert r.bitsC == uint64(3)
-assert r.largeBits1 == uint64(300)
-assert r.spacer == uint64(5)
-assert r.largeBits2 == uint64(1329)
-assert r.normalS2 == int16(-1)
-assert r.byte8910 == uint64(5259587)
-assert r.byte11To14 == uint64(1261262125)
-assert r.byte15To19 == uint64(293220057087'i64)
-assert r.byte20To27 == uint64(18446744073709551615'u64)
-assert r.testIfB1 == int8(123)
+assert r.byte1 == 80
+assert r.byte2 == 65
+assert r.bitsA == false
+assert r.bitsB == 4
+assert r.bitsC == 3
+assert r.largeBits1 == 300
+assert r.spacer == 5
+assert r.largeBits2 == 1329
+assert r.normalS2 == -1
+assert r.byte8910 == 5259587
+assert r.byte11To14 == 1261262125
+assert r.byte15To19 == 293220057087'i64
+assert r.byte20To27 == 18446744073709551615'u64
+assert r.testIfB1 == 123
diff --git a/spec/nim/tbits_simple_le.nim b/spec/nim/tbits_simple_le.nim
index b2dcff219..3a214982f 100644
--- a/spec/nim/tbits_simple_le.nim
+++ b/spec/nim/tbits_simple_le.nim
@@ -6,17 +6,17 @@ import auxiliary/test_utils
 
 let r = BitsSimpleLe.fromFile("src/fixed_struct.bin")
 
-assert r.byte1 == uint64(80)
-assert r.byte2 == uint64(65)
-assert r.bitsA == bool(true)
-assert r.bitsB == uint64(1)
-assert r.bitsC == uint64(4)
-assert r.largeBits1 == uint64(331)
-assert r.spacer == uint64(3)
-assert r.largeBits2 == uint64(393)
-assert r.normalS2 == int16(-1)
-assert r.byte8910 == uint64(4407632)
-assert r.byte11To14 == uint64(760556875)
-assert r.byte15To19 == uint64(1099499455812'i64)
-assert r.byte20To27 == uint64(18446744073709551615'u64)
-assert r.testIfB1 == int8(123)
+assert r.byte1 == 80
+assert r.byte2 == 65
+assert r.bitsA == true
+assert r.bitsB == 1
+assert r.bitsC == 4
+assert r.largeBits1 == 331
+assert r.spacer == 3
+assert r.largeBits2 == 393
+assert r.normalS2 == -1
+assert r.byte8910 == 4407632
+assert r.byte11To14 == 760556875
+assert r.byte15To19 == 1099499455812'i64
+assert r.byte20To27 == 18446744073709551615'u64
+assert r.testIfB1 == 123
diff --git a/spec/nim/tbuffered_struct.nim b/spec/nim/tbuffered_struct.nim
index f3eec45d4..9075be2fe 100644
--- a/spec/nim/tbuffered_struct.nim
+++ b/spec/nim/tbuffered_struct.nim
@@ -6,10 +6,10 @@ import auxiliary/test_utils
 
 let r = BufferedStruct.fromFile("src/buffered_struct.bin")
 
-assert r.len1 == uint32(16)
-assert r.block1.number1 == uint32(66)
-assert r.block1.number2 == uint32(67)
-assert r.len2 == uint32(8)
-assert r.block2.number1 == uint32(68)
-assert r.block2.number2 == uint32(69)
-assert r.finisher == uint32(238)
+assert r.len1 == 16
+assert r.block1.number1 == 66
+assert r.block1.number2 == 67
+assert r.len2 == 8
+assert r.block2.number1 == 68
+assert r.block2.number2 == 69
+assert r.finisher == 238
diff --git a/spec/nim/tcast_nested.nim b/spec/nim/tcast_nested.nim
index 279aa6d83..403a12310 100644
--- a/spec/nim/tcast_nested.nim
+++ b/spec/nim/tcast_nested.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = CastNested.fromFile("src/switch_opcodes.bin")
 
-assert r.opcodes0Str.value == string("foobar")
-assert r.opcodes0StrValue == string("foobar")
-assert r.opcodes1Int.value == uint8(66)
-assert r.opcodes1IntValue == uint8(66)
+assert r.opcodes0Str.value == "foobar"
+assert r.opcodes0StrValue == "foobar"
+assert r.opcodes1Int.value == 66
+assert r.opcodes1IntValue == 66
diff --git a/spec/nim/tcast_to_imported.nim b/spec/nim/tcast_to_imported.nim
index fcd610901..f0d592de9 100644
--- a/spec/nim/tcast_to_imported.nim
+++ b/spec/nim/tcast_to_imported.nim
@@ -7,5 +7,5 @@ import auxiliary/test_utils
 
 let r = CastToImported.fromFile("src/fixed_struct.bin")
 
-assert r.one.one == uint8(80)
-assert r.oneCasted.one == uint8(80)
+assert r.one.one == 80
+assert r.oneCasted.one == 80
diff --git a/spec/nim/tcast_to_top.nim b/spec/nim/tcast_to_top.nim
index 0b841d9ce..0b6ded919 100644
--- a/spec/nim/tcast_to_top.nim
+++ b/spec/nim/tcast_to_top.nim
@@ -6,6 +6,6 @@ import auxiliary/test_utils
 
 let r = CastToTop.fromFile("src/fixed_struct.bin")
 
-assert r.code == uint8(80)
-assert r.header.code == uint8(65)
-assert r.headerCasted.code == uint8(65)
+assert r.code == 80
+assert r.header.code == 65
+assert r.headerCasted.code == 65
diff --git a/spec/nim/tcombine_bool.nim b/spec/nim/tcombine_bool.nim
index 36690f35a..ed086d532 100644
--- a/spec/nim/tcombine_bool.nim
+++ b/spec/nim/tcombine_bool.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = CombineBool.fromFile("src/enum_negative.bin")
 
-assert r.boolBit == bool(true)
-assert r.boolCalcBit == bool(false)
+assert r.boolBit == true
+assert r.boolCalcBit == false
diff --git a/spec/nim/tcombine_str.nim b/spec/nim/tcombine_str.nim
index 96f54b355..f65362f10 100644
--- a/spec/nim/tcombine_str.nim
+++ b/spec/nim/tcombine_str.nim
@@ -6,18 +6,18 @@ import auxiliary/test_utils
 
 let r = CombineStr.fromFile("src/term_strz.bin")
 
-assert r.strTerm == string("foo")
-assert r.strLimit == string("bar|")
-assert r.strEos == string("baz@")
-assert r.strCalc == string("bar")
-assert r.strCalcBytes == string("baz")
-assert r.termOrLimit == string("foo")
-assert r.termOrEos == string("baz@")
-assert r.termOrCalc == string("foo")
-assert r.termOrCalcBytes == string("baz")
-assert r.limitOrEos == string("bar|")
-assert r.limitOrCalc == string("bar")
-assert r.limitOrCalcBytes == string("bar|")
-assert r.eosOrCalc == string("bar")
-assert r.eosOrCalcBytes == string("baz@")
-assert r.calcOrCalcBytes == string("baz")
+assert r.strTerm == "foo"
+assert r.strLimit == "bar|"
+assert r.strEos == "baz@"
+assert r.strCalc == "bar"
+assert r.strCalcBytes == "baz"
+assert r.termOrLimit == "foo"
+assert r.termOrEos == "baz@"
+assert r.termOrCalc == "foo"
+assert r.termOrCalcBytes == "baz"
+assert r.limitOrEos == "bar|"
+assert r.limitOrCalc == "bar"
+assert r.limitOrCalcBytes == "bar|"
+assert r.eosOrCalc == "bar"
+assert r.eosOrCalcBytes == "baz@"
+assert r.calcOrCalcBytes == "baz"
diff --git a/spec/nim/tdebug_switch_user.nim b/spec/nim/tdebug_switch_user.nim
index 5a541cb3d..360678018 100644
--- a/spec/nim/tdebug_switch_user.nim
+++ b/spec/nim/tdebug_switch_user.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = DebugSwitchUser.fromFile("src/nav_parent_switch.bin")
 
-assert r.code == uint8(1)
-assert (DebugSwitchUser_One(r.data)).val == int16(-190)
+assert r.code == 1
+assert (DebugSwitchUser_One(r.data)).val == -190
diff --git a/spec/nim/tdefault_big_endian.nim b/spec/nim/tdefault_big_endian.nim
index c781027ae..8296e11e3 100644
--- a/spec/nim/tdefault_big_endian.nim
+++ b/spec/nim/tdefault_big_endian.nim
@@ -6,4 +6,4 @@ import auxiliary/test_utils
 
 let r = DefaultBigEndian.fromFile("src/enum_0.bin")
 
-assert r.one == uint32(117440512)
+assert r.one == 117440512
diff --git a/spec/nim/tdefault_bit_endian_mod.nim b/spec/nim/tdefault_bit_endian_mod.nim
index 53402c725..76f3363ed 100644
--- a/spec/nim/tdefault_bit_endian_mod.nim
+++ b/spec/nim/tdefault_bit_endian_mod.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = DefaultBitEndianMod.fromFile("src/fixed_struct.bin")
 
-assert r.main.one == uint64(336)
-assert r.main.two == uint64(8608)
-assert r.main.nest.two == uint64(11595)
-assert r.main.nestBe.two == uint64(12799)
+assert r.main.one == 336
+assert r.main.two == 8608
+assert r.main.nest.two == 11595
+assert r.main.nestBe.two == 12799
diff --git a/spec/nim/tdefault_endian_expr_inherited.nim b/spec/nim/tdefault_endian_expr_inherited.nim
index 5e1c14baa..a4ae55d41 100644
--- a/spec/nim/tdefault_endian_expr_inherited.nim
+++ b/spec/nim/tdefault_endian_expr_inherited.nim
@@ -7,17 +7,17 @@ import auxiliary/test_utils
 let r = DefaultEndianExprInherited.fromFile("src/endian_expr.bin")
 
 assert r.docs[0].indicator == @[73'u8, 73'u8]
-assert r.docs[0].main.insides.someInt == uint32(66)
-assert r.docs[0].main.insides.more.someInt1 == uint16(16896)
-assert r.docs[0].main.insides.more.someInt2 == uint16(66)
-assert r.docs[0].main.insides.more.someInst == uint32(66)
+assert r.docs[0].main.insides.someInt == 66
+assert r.docs[0].main.insides.more.someInt1 == 16896
+assert r.docs[0].main.insides.more.someInt2 == 66
+assert r.docs[0].main.insides.more.someInst == 66
 assert r.docs[1].indicator == @[77'u8, 77'u8]
-assert r.docs[1].main.insides.someInt == uint32(66)
-assert r.docs[1].main.insides.more.someInt1 == uint16(66)
-assert r.docs[1].main.insides.more.someInt2 == uint16(16896)
-assert r.docs[1].main.insides.more.someInst == uint32(1107296256)
+assert r.docs[1].main.insides.someInt == 66
+assert r.docs[1].main.insides.more.someInt1 == 66
+assert r.docs[1].main.insides.more.someInt2 == 16896
+assert r.docs[1].main.insides.more.someInst == 1107296256
 assert r.docs[2].indicator == @[88'u8, 88'u8]
-assert r.docs[2].main.insides.someInt == uint32(66)
-assert r.docs[2].main.insides.more.someInt1 == uint16(66)
-assert r.docs[2].main.insides.more.someInt2 == uint16(16896)
-assert r.docs[2].main.insides.more.someInst == uint32(1107296256)
+assert r.docs[2].main.insides.someInt == 66
+assert r.docs[2].main.insides.more.someInt1 == 66
+assert r.docs[2].main.insides.more.someInt2 == 16896
+assert r.docs[2].main.insides.more.someInst == 1107296256
diff --git a/spec/nim/tdefault_endian_expr_is_be.nim b/spec/nim/tdefault_endian_expr_is_be.nim
index 3cba7d8d0..68e5b00f7 100644
--- a/spec/nim/tdefault_endian_expr_is_be.nim
+++ b/spec/nim/tdefault_endian_expr_is_be.nim
@@ -7,20 +7,20 @@ import auxiliary/test_utils
 let r = DefaultEndianExprIsBe.fromFile("src/endian_expr.bin")
 
 assert r.docs[0].indicator == @[73'u8, 73'u8]
-assert r.docs[0].main.someInt == uint32(66)
-assert r.docs[0].main.someIntBe == uint16(66)
-assert r.docs[0].main.someIntLe == uint16(66)
-assert r.docs[0].main.instInt == uint32(66)
-assert r.docs[0].main.instSub.foo == uint32(66)
+assert r.docs[0].main.someInt == 66
+assert r.docs[0].main.someIntBe == 66
+assert r.docs[0].main.someIntLe == 66
+assert r.docs[0].main.instInt == 66
+assert r.docs[0].main.instSub.foo == 66
 assert r.docs[1].indicator == @[77'u8, 77'u8]
-assert r.docs[1].main.someInt == uint32(66)
-assert r.docs[1].main.someIntBe == uint16(66)
-assert r.docs[1].main.someIntLe == uint16(66)
-assert r.docs[1].main.instInt == uint32(1107296256)
-assert r.docs[1].main.instSub.foo == uint32(1107296256)
+assert r.docs[1].main.someInt == 66
+assert r.docs[1].main.someIntBe == 66
+assert r.docs[1].main.someIntLe == 66
+assert r.docs[1].main.instInt == 1107296256
+assert r.docs[1].main.instSub.foo == 1107296256
 assert r.docs[2].indicator == @[88'u8, 88'u8]
-assert r.docs[2].main.someInt == uint32(1107296256)
-assert r.docs[2].main.someIntBe == uint16(66)
-assert r.docs[2].main.someIntLe == uint16(66)
-assert r.docs[2].main.instInt == uint32(66)
-assert r.docs[2].main.instSub.foo == uint32(66)
+assert r.docs[2].main.someInt == 1107296256
+assert r.docs[2].main.someIntBe == 66
+assert r.docs[2].main.someIntLe == 66
+assert r.docs[2].main.instInt == 66
+assert r.docs[2].main.instSub.foo == 66
diff --git a/spec/nim/tdefault_endian_expr_is_le.nim b/spec/nim/tdefault_endian_expr_is_le.nim
index 42d0e013d..7a2ff26ae 100644
--- a/spec/nim/tdefault_endian_expr_is_le.nim
+++ b/spec/nim/tdefault_endian_expr_is_le.nim
@@ -7,14 +7,14 @@ import auxiliary/test_utils
 let r = DefaultEndianExprIsLe.fromFile("src/endian_expr.bin")
 
 assert r.docs[0].indicator == @[73'u8, 73'u8]
-assert r.docs[0].main.someInt == uint32(66)
-assert r.docs[0].main.someIntBe == uint16(66)
-assert r.docs[0].main.someIntLe == uint16(66)
+assert r.docs[0].main.someInt == 66
+assert r.docs[0].main.someIntBe == 66
+assert r.docs[0].main.someIntLe == 66
 assert r.docs[1].indicator == @[77'u8, 77'u8]
-assert r.docs[1].main.someInt == uint32(66)
-assert r.docs[1].main.someIntBe == uint16(66)
-assert r.docs[1].main.someIntLe == uint16(66)
+assert r.docs[1].main.someInt == 66
+assert r.docs[1].main.someIntBe == 66
+assert r.docs[1].main.someIntLe == 66
 assert r.docs[2].indicator == @[88'u8, 88'u8]
-assert r.docs[2].main.someInt == uint32(66)
-assert r.docs[2].main.someIntBe == uint16(66)
-assert r.docs[2].main.someIntLe == uint16(66)
+assert r.docs[2].main.someInt == 66
+assert r.docs[2].main.someIntBe == 66
+assert r.docs[2].main.someIntLe == 66
diff --git a/spec/nim/tdefault_endian_mod.nim b/spec/nim/tdefault_endian_mod.nim
index bdf73aa79..abbe7165f 100644
--- a/spec/nim/tdefault_endian_mod.nim
+++ b/spec/nim/tdefault_endian_mod.nim
@@ -6,6 +6,6 @@ import auxiliary/test_utils
 
 let r = DefaultEndianMod.fromFile("src/fixed_struct.bin")
 
-assert r.main.one == int32(1262698832)
-assert r.main.nest.two == int32(-52947)
-assert r.main.nestBe.two == int32(1346454347)
+assert r.main.one == 1262698832
+assert r.main.nest.two == -52947
+assert r.main.nestBe.two == 1346454347
diff --git a/spec/nim/tenum_deep_literals.nim b/spec/nim/tenum_deep_literals.nim
index 27ba04ea4..4d0172240 100644
--- a/spec/nim/tenum_deep_literals.nim
+++ b/spec/nim/tenum_deep_literals.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = EnumDeepLiterals.fromFile("src/enum_0.bin")
 
-assert r.isPet1Ok == bool(true)
-assert r.isPet2Ok == bool(true)
+assert r.isPet1Ok == true
+assert r.isPet2Ok == true
diff --git a/spec/nim/tenum_if.nim b/spec/nim/tenum_if.nim
index c726469c5..0f1c74d40 100644
--- a/spec/nim/tenum_if.nim
+++ b/spec/nim/tenum_if.nim
@@ -7,9 +7,9 @@ import auxiliary/test_utils
 let r = EnumIf.fromFile("src/if_struct.bin")
 
 assert r.op1.opcode == enum_if.a_string
-assert r.op1.argStr.str == string("foo")
+assert r.op1.argStr.str == "foo"
 assert r.op2.opcode == enum_if.a_tuple
-assert r.op2.argTuple.num1 == uint8(66)
-assert r.op2.argTuple.num2 == uint8(67)
+assert r.op2.argTuple.num1 == 66
+assert r.op2.argTuple.num2 == 67
 assert r.op3.opcode == enum_if.a_string
-assert r.op3.argStr.str == string("bar")
+assert r.op3.argStr.str == "bar"
diff --git a/spec/nim/tenum_invalid.nim b/spec/nim/tenum_invalid.nim
index 603abaf96..e0b089bb9 100644
--- a/spec/nim/tenum_invalid.nim
+++ b/spec/nim/tenum_invalid.nim
@@ -7,4 +7,4 @@ import auxiliary/test_utils
 let r = EnumInvalid.fromFile("src/term_strz.bin")
 
 assert r.pet1 == enum_invalid.dog
-assert r.pet2 == EnumInvalid_Animal(111)
+assert r.pet2 == 111
diff --git a/spec/nim/tenum_to_i.nim b/spec/nim/tenum_to_i.nim
index 911f6d99a..395fd3fad 100644
--- a/spec/nim/tenum_to_i.nim
+++ b/spec/nim/tenum_to_i.nim
@@ -8,8 +8,8 @@ let r = EnumToI.fromFile("src/enum_0.bin")
 
 assert r.pet1 == enum_to_i.cat
 assert r.pet2 == enum_to_i.chicken
-assert r.pet1I == int(7)
-assert r.pet1Mod == int(32775)
-assert r.oneLtTwo == bool(true)
-assert r.pet1EqInt == bool(true)
-assert r.pet2EqInt == bool(false)
+assert r.pet1I == 7
+assert r.pet1Mod == 32775
+assert r.oneLtTwo == true
+assert r.pet1EqInt == true
+assert r.pet2EqInt == false
diff --git a/spec/nim/tenum_to_i_class_border_1.nim b/spec/nim/tenum_to_i_class_border_1.nim
index 4eb8c056c..7a7b8e01e 100644
--- a/spec/nim/tenum_to_i_class_border_1.nim
+++ b/spec/nim/tenum_to_i_class_border_1.nim
@@ -9,4 +9,4 @@ let r = EnumToIClassBorder1.fromFile("src/enum_0.bin")
 
 assert r.pet1 == enum_to_i_class_border_1.cat
 assert r.pet2 == enum_to_i_class_border_1.chicken
-assert r.checker.isDog == bool(true)
+assert r.checker.isDog == true
diff --git a/spec/nim/texpr_0.nim b/spec/nim/texpr_0.nim
index ea8b4051d..55a581639 100644
--- a/spec/nim/texpr_0.nim
+++ b/spec/nim/texpr_0.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = Expr0.fromFile("src/str_encodings.bin")
 
-assert r.mustBeF7 == int(247)
-assert r.mustBeAbc123 == string("abc123")
+assert r.mustBeF7 == 247
+assert r.mustBeAbc123 == "abc123"
diff --git a/spec/nim/texpr_1.nim b/spec/nim/texpr_1.nim
index dea2a9225..98e5cbe28 100644
--- a/spec/nim/texpr_1.nim
+++ b/spec/nim/texpr_1.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = Expr1.fromFile("src/str_encodings.bin")
 
-assert r.lenOf1 == uint16(10)
-assert r.lenOf1Mod == int(8)
-assert r.str1 == string("Some ASC")
-assert r.str1Len == int(8)
+assert r.lenOf1 == 10
+assert r.lenOf1Mod == 8
+assert r.str1 == "Some ASC"
+assert r.str1Len == 8
diff --git a/spec/nim/texpr_2.nim b/spec/nim/texpr_2.nim
index 6258b03ca..75e5869c6 100644
--- a/spec/nim/texpr_2.nim
+++ b/spec/nim/texpr_2.nim
@@ -6,20 +6,20 @@ import auxiliary/test_utils
 
 let r = Expr2.fromFile("src/str_encodings.bin")
 
-assert r.str1.lenOrig == uint16(10)
-assert r.str1.lenMod == int(7)
-assert r.str1.str == string("Some AS")
-assert r.str1Len == int(7)
-assert r.str1LenMod == int(7)
-assert r.str1Byte1 == uint8(73)
-assert r.str1Avg == int(73)
-assert r.str1Char5 == string("e")
-assert r.str1Tuple5.byte0 == uint8(101)
-assert r.str1Tuple5.byte0 == uint8(101)
-assert r.str1Tuple5.byte1 == uint8(32)
-assert r.str1Tuple5.byte2 == uint8(65)
-assert r.str1Tuple5.avg == int(48)
-assert r.str2Tuple5.byte0 == uint8(101)
-assert r.str2Tuple5.byte1 == uint8(32)
-assert r.str2Tuple5.byte2 == uint8(65)
-assert r.str2Tuple5.avg == int(48)
+assert r.str1.lenOrig == 10
+assert r.str1.lenMod == 7
+assert r.str1.str == "Some AS"
+assert r.str1Len == 7
+assert r.str1LenMod == 7
+assert r.str1Byte1 == 73
+assert r.str1Avg == 73
+assert r.str1Char5 == "e"
+assert r.str1Tuple5.byte0 == 101
+assert r.str1Tuple5.byte0 == 101
+assert r.str1Tuple5.byte1 == 32
+assert r.str1Tuple5.byte2 == 65
+assert r.str1Tuple5.avg == 48
+assert r.str2Tuple5.byte0 == 101
+assert r.str2Tuple5.byte1 == 32
+assert r.str2Tuple5.byte2 == 65
+assert r.str2Tuple5.avg == 48
diff --git a/spec/nim/texpr_3.nim b/spec/nim/texpr_3.nim
index 6df9fe43c..1c025cf7e 100644
--- a/spec/nim/texpr_3.nim
+++ b/spec/nim/texpr_3.nim
@@ -6,15 +6,15 @@ import auxiliary/test_utils
 
 let r = Expr3.fromFile("src/fixed_struct.bin")
 
-assert r.one == uint8(80)
-assert r.two == string("ACK")
-assert r.three == string("@ACK")
-assert r.four == string("_ACK_")
-assert r.isStrEq == bool(true)
-assert r.isStrNe == bool(false)
-assert r.isStrLt == bool(true)
-assert r.isStrGt == bool(false)
-assert r.isStrLe == bool(true)
-assert r.isStrGe == bool(false)
-assert r.isStrLt2 == bool(true)
-assert r.testNot == bool(true)
+assert r.one == 80
+assert r.two == "ACK"
+assert r.three == "@ACK"
+assert r.four == "_ACK_"
+assert r.isStrEq == true
+assert r.isStrNe == false
+assert r.isStrLt == true
+assert r.isStrGt == false
+assert r.isStrLe == true
+assert r.isStrGe == false
+assert r.isStrLt2 == true
+assert r.testNot == true
diff --git a/spec/nim/texpr_array.nim b/spec/nim/texpr_array.nim
index 3936855fc..a8f821285 100644
--- a/spec/nim/texpr_array.nim
+++ b/spec/nim/texpr_array.nim
@@ -6,18 +6,18 @@ import auxiliary/test_utils
 
 let r = ExprArray.fromFile("src/expr_array.bin")
 
-assert r.aintSize == int(4)
-assert r.aintFirst == uint32(7657765)
-assert r.aintLast == uint32(16272640)
-assert r.aintMin == uint32(49185)
-assert r.aintMax == uint32(1123362332)
-assert r.afloatSize == int(3)
-assert r.afloatFirst == float64(-2.6839530254859364E-121)
-assert r.afloatLast == float64(-1.1103359815095273E-175)
-assert r.afloatMin == float64(-8.754689149998834E+288)
-assert r.afloatMax == float64(-1.1103359815095273E-175)
-assert r.astrSize == int(3)
-assert r.astrFirst == string("foo")
-assert r.astrLast == string("baz")
-assert r.astrMin == string("bar")
-assert r.astrMax == string("foo")
+assert r.aintSize == 4
+assert r.aintFirst == 7657765
+assert r.aintLast == 16272640
+assert r.aintMin == 49185
+assert r.aintMax == 1123362332
+assert r.afloatSize == 3
+assert r.afloatFirst == -2.6839530254859364E-121
+assert r.afloatLast == -1.1103359815095273E-175
+assert r.afloatMin == -8.754689149998834E+288
+assert r.afloatMax == -1.1103359815095273E-175
+assert r.astrSize == 3
+assert r.astrFirst == "foo"
+assert r.astrLast == "baz"
+assert r.astrMin == "bar"
+assert r.astrMax == "foo"
diff --git a/spec/nim/texpr_bits.nim b/spec/nim/texpr_bits.nim
index 7e5bf603a..10aa2e264 100644
--- a/spec/nim/texpr_bits.nim
+++ b/spec/nim/texpr_bits.nim
@@ -6,13 +6,13 @@ import auxiliary/test_utils
 
 let r = ExprBits.fromFile("src/switch_opcodes.bin")
 
-assert r.a == uint64(2)
+assert r.a == 2
 assert r.enumSeq == expr_bits.foo
 assert r.byteSize == @[102'u8, 111'u8]
-assert len(r.repeatExpr) == int(2)
-assert r.repeatExpr[0] == int8(111)
-assert r.repeatExpr[1] == int8(98)
-assert r.switchOnType == int8(97)
-assert r.switchOnEndian.foo == int16(29184)
+assert len(r.repeatExpr) == 2
+assert r.repeatExpr[0] == 111
+assert r.repeatExpr[1] == 98
+assert r.switchOnType == 97
+assert r.switchOnEndian.foo == 29184
 assert r.enumInst == expr_bits.bar
-assert r.instPos == int8(111)
+assert r.instPos == 111
diff --git a/spec/nim/texpr_bytes_cmp.nim b/spec/nim/texpr_bytes_cmp.nim
index d2d0b2b0a..0efc4bc93 100644
--- a/spec/nim/texpr_bytes_cmp.nim
+++ b/spec/nim/texpr_bytes_cmp.nim
@@ -8,11 +8,11 @@ let r = ExprBytesCmp.fromFile("src/fixed_struct.bin")
 
 assert r.one == @[80'u8]
 assert r.two == @[65'u8, 67'u8, 75'u8]
-assert r.isEq == bool(true)
-assert r.isNe == bool(false)
-assert r.isLt == bool(true)
-assert r.isGt == bool(false)
-assert r.isLe == bool(true)
-assert r.isGe == bool(false)
-assert r.isLt2 == bool(false)
-assert r.isGt2 == bool(true)
+assert r.isEq == true
+assert r.isNe == false
+assert r.isLt == true
+assert r.isGt == false
+assert r.isLe == true
+assert r.isGe == false
+assert r.isLt2 == false
+assert r.isGt2 == true
diff --git a/spec/nim/texpr_bytes_literal.nim b/spec/nim/texpr_bytes_literal.nim
index 6b7ae2bc4..8ca656e2b 100644
--- a/spec/nim/texpr_bytes_literal.nim
+++ b/spec/nim/texpr_bytes_literal.nim
@@ -6,6 +6,6 @@ import auxiliary/test_utils
 
 let r = ExprBytesLiteral.fromFile("src/enum_negative.bin")
 
-assert len(r.literal) == int(2)
-assert r.literal[0] == uint8(-1)
-assert r.literal[1] == uint8(1)
+assert len(r.literal) == 2
+assert r.literal[0] == -1
+assert r.literal[1] == 1
diff --git a/spec/nim/texpr_bytes_ops.nim b/spec/nim/texpr_bytes_ops.nim
index 9278ec72b..01545d50f 100644
--- a/spec/nim/texpr_bytes_ops.nim
+++ b/spec/nim/texpr_bytes_ops.nim
@@ -7,19 +7,19 @@ import strutils
 
 let r = ExprBytesOps.fromFile("src/nav_parent_switch.bin")
 
-assert r.oneSize == int(3)
-assert r.oneFirst == uint8(1)
-assert r.oneMid == uint8(66)
-assert r.oneLast == uint8(255)
-assert intToStr(int(r.oneLast)) == string("255")
-assert r.oneMin == uint8(1)
-assert r.oneMax == uint8(255)
-assert intToStr(int(r.oneMax)) == string("255")
-assert r.twoSize == int(3)
-assert r.twoFirst == uint8(65)
-assert r.twoMid == uint8(255)
-assert intToStr(int(r.twoMid)) == string("255")
-assert r.twoLast == uint8(75)
-assert r.twoMin == uint8(65)
-assert r.twoMax == uint8(255)
-assert intToStr(int(r.twoMax)) == string("255")
+assert r.oneSize == 3
+assert r.oneFirst == 1
+assert r.oneMid == 66
+assert r.oneLast == 255
+assert intToStr(int(r.oneLast)) == "255"
+assert r.oneMin == 1
+assert r.oneMax == 255
+assert intToStr(int(r.oneMax)) == "255"
+assert r.twoSize == 3
+assert r.twoFirst == 65
+assert r.twoMid == 255
+assert intToStr(int(r.twoMid)) == "255"
+assert r.twoLast == 75
+assert r.twoMin == 65
+assert r.twoMax == 255
+assert intToStr(int(r.twoMax)) == "255"
diff --git a/spec/nim/texpr_calc_array_ops.nim b/spec/nim/texpr_calc_array_ops.nim
index 5fcdea29f..241f90996 100644
--- a/spec/nim/texpr_calc_array_ops.nim
+++ b/spec/nim/texpr_calc_array_ops.nim
@@ -6,21 +6,21 @@ import auxiliary/test_utils
 
 let r = ExprCalcArrayOps.fromFile("src/fixed_struct.bin")
 
-assert r.intArraySize == int(7)
-assert r.intArrayFirst == int(10)
-assert r.intArrayMid == int(25)
-assert r.intArrayLast == int(1000)
-assert r.intArrayMin == int(10)
-assert r.intArrayMax == int(1000)
-assert r.doubleArraySize == int(5)
-assert r.doubleArrayFirst == float64(10.0)
-assert r.doubleArrayMid == float64(25.0)
-assert r.doubleArrayLast == float64(3.14159)
-assert r.doubleArrayMin == float64(3.14159)
-assert r.doubleArrayMax == float64(100.0)
-assert r.strArraySize == int(4)
-assert r.strArrayFirst == string("un")
-assert r.strArrayMid == string("deux")
-assert r.strArrayLast == string("quatre")
-assert r.strArrayMin == string("deux")
-assert r.strArrayMax == string("un")
+assert r.intArraySize == 7
+assert r.intArrayFirst == 10
+assert r.intArrayMid == 25
+assert r.intArrayLast == 1000
+assert r.intArrayMin == 10
+assert r.intArrayMax == 1000
+assert r.doubleArraySize == 5
+assert r.doubleArrayFirst == 10.0
+assert r.doubleArrayMid == 25.0
+assert r.doubleArrayLast == 3.14159
+assert r.doubleArrayMin == 3.14159
+assert r.doubleArrayMax == 100.0
+assert r.strArraySize == 4
+assert r.strArrayFirst == "un"
+assert r.strArrayMid == "deux"
+assert r.strArrayLast == "quatre"
+assert r.strArrayMin == "deux"
+assert r.strArrayMax == "un"
diff --git a/spec/nim/texpr_if_int_ops.nim b/spec/nim/texpr_if_int_ops.nim
index f77793842..b60112b28 100644
--- a/spec/nim/texpr_if_int_ops.nim
+++ b/spec/nim/texpr_if_int_ops.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = ExprIfIntOps.fromFile("src/process_coerce_switch.bin")
 
-assert r.isEqPrim == bool(true)
-assert r.isEqBoxed == bool(true)
+assert r.isEqPrim == true
+assert r.isEqBoxed == true
diff --git a/spec/nim/texpr_int_div.nim b/spec/nim/texpr_int_div.nim
index 223834295..c4371d860 100644
--- a/spec/nim/texpr_int_div.nim
+++ b/spec/nim/texpr_int_div.nim
@@ -6,9 +6,9 @@ import auxiliary/test_utils
 
 let r = ExprIntDiv.fromFile("src/fixed_struct.bin")
 
-assert r.intU == uint32(1262698832)
-assert r.intS == int32(-52947)
-assert r.divPosConst == int(756)
-assert r.divNegConst == int(-757)
-assert r.divPosSeq == int(97130679)
-assert r.divNegSeq == int(-4073)
+assert r.intU == 1262698832
+assert r.intS == -52947
+assert r.divPosConst == 756
+assert r.divNegConst == -757
+assert r.divPosSeq == 97130679
+assert r.divNegSeq == -4073
diff --git a/spec/nim/texpr_io_eof.nim b/spec/nim/texpr_io_eof.nim
index 8b0b48b1c..f53d1f23f 100644
--- a/spec/nim/texpr_io_eof.nim
+++ b/spec/nim/texpr_io_eof.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = ExprIoEof.fromFile("src/fixed_struct.bin")
 
-assert r.substream1.one == uint32(1262698832)
+assert r.substream1.one == 1262698832
 assert r.substream1.two == 0'u32
-assert r.substream2.one == uint32(4294914349'i64)
-assert r.substream2.two == uint32(1262698832)
+assert r.substream2.one == 4294914349'i64
+assert r.substream2.two == 1262698832
diff --git a/spec/nim/texpr_io_pos.nim b/spec/nim/texpr_io_pos.nim
index 3f6c84c5a..17038411f 100644
--- a/spec/nim/texpr_io_pos.nim
+++ b/spec/nim/texpr_io_pos.nim
@@ -6,9 +6,9 @@ import auxiliary/test_utils
 
 let r = ExprIoPos.fromFile("src/expr_io_pos.bin")
 
-assert r.substream1.myStr == string("CURIOSITY")
+assert r.substream1.myStr == "CURIOSITY"
 assert r.substream1.body == @[17'u8, 34'u8, 51'u8, 68'u8]
-assert r.substream1.number == uint16(66)
-assert r.substream2.myStr == string("KILLED")
+assert r.substream1.number == 66
+assert r.substream2.myStr == "KILLED"
 assert r.substream2.body == @[97'u8, 32'u8, 99'u8, 97'u8, 116'u8]
-assert r.substream2.number == uint16(103)
+assert r.substream2.number == 103
diff --git a/spec/nim/texpr_mod.nim b/spec/nim/texpr_mod.nim
index 4e425ca19..40b306823 100644
--- a/spec/nim/texpr_mod.nim
+++ b/spec/nim/texpr_mod.nim
@@ -6,9 +6,9 @@ import auxiliary/test_utils
 
 let r = ExprMod.fromFile("src/fixed_struct.bin")
 
-assert r.intU == uint32(1262698832)
-assert r.intS == int32(-52947)
-assert r.modPosConst == int(9)
-assert r.modNegConst == int(4)
-assert r.modPosSeq == int(5)
-assert r.modNegSeq == int(2)
+assert r.intU == 1262698832
+assert r.intS == -52947
+assert r.modPosConst == 9
+assert r.modNegConst == 4
+assert r.modPosSeq == 5
+assert r.modNegSeq == 2
diff --git a/spec/nim/texpr_ops_parens.nim b/spec/nim/texpr_ops_parens.nim
index 68d1c84c8..438006e4b 100644
--- a/spec/nim/texpr_ops_parens.nim
+++ b/spec/nim/texpr_ops_parens.nim
@@ -6,12 +6,12 @@ import auxiliary/test_utils
 
 let r = ExprOpsParens.fromFile("src/enum_negative.bin")
 
-assert r.iSumToStr == string("29")
-assert r.fSumToInt == int(9)
-assert r.strConcatLen == int(10)
-assert r.strConcatRev == string("9876543210")
-assert r.strConcatSubstr2To7 == string("23456")
-assert r.strConcatToI == int(123456789)
-assert r.boolEq == int(0)
-assert r.boolAnd == int(0)
-assert r.boolOr == int(1)
+assert r.iSumToStr == "29"
+assert r.fSumToInt == 9
+assert r.strConcatLen == 10
+assert r.strConcatRev == "9876543210"
+assert r.strConcatSubstr2To7 == "23456"
+assert r.strConcatToI == 123456789
+assert r.boolEq == 0
+assert r.boolAnd == 0
+assert r.boolOr == 1
diff --git a/spec/nim/texpr_sizeof_type_0.nim b/spec/nim/texpr_sizeof_type_0.nim
index fcfeef276..1d42ef792 100644
--- a/spec/nim/texpr_sizeof_type_0.nim
+++ b/spec/nim/texpr_sizeof_type_0.nim
@@ -6,4 +6,4 @@ import auxiliary/test_utils
 
 let r = ExprSizeofType0.fromFile("src/fixed_struct.bin")
 
-assert r.sizeofBlock == int(((1 + 4) + 2))
+assert r.sizeofBlock == ((1 + 4) + 2)
diff --git a/spec/nim/texpr_sizeof_type_1.nim b/spec/nim/texpr_sizeof_type_1.nim
index 982686b1a..73bd99a83 100644
--- a/spec/nim/texpr_sizeof_type_1.nim
+++ b/spec/nim/texpr_sizeof_type_1.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = ExprSizeofType1.fromFile("src/fixed_struct.bin")
 
-assert r.sizeofBlock == int((((1 + 4) + 2) + 4))
-assert r.sizeofSubblock == int(4)
+assert r.sizeofBlock == (((1 + 4) + 2) + 4)
+assert r.sizeofSubblock == 4
diff --git a/spec/nim/texpr_sizeof_value_0.nim b/spec/nim/texpr_sizeof_value_0.nim
index 16118afbe..1fd275682 100644
--- a/spec/nim/texpr_sizeof_value_0.nim
+++ b/spec/nim/texpr_sizeof_value_0.nim
@@ -6,8 +6,8 @@ import auxiliary/test_utils
 
 let r = ExprSizeofValue0.fromFile("src/fixed_struct.bin")
 
-assert r.selfSizeof == int((((1 + 4) + 2) + 2))
-assert r.sizeofBlock == int(((1 + 4) + 2))
-assert r.sizeofBlockA == int(1)
-assert r.sizeofBlockB == int(4)
-assert r.sizeofBlockC == int(2)
+assert r.selfSizeof == (((1 + 4) + 2) + 2)
+assert r.sizeofBlock == ((1 + 4) + 2)
+assert r.sizeofBlockA == 1
+assert r.sizeofBlockB == 4
+assert r.sizeofBlockC == 2
diff --git a/spec/nim/texpr_sizeof_value_sized.nim b/spec/nim/texpr_sizeof_value_sized.nim
index ad2ea0f0d..d8516766b 100644
--- a/spec/nim/texpr_sizeof_value_sized.nim
+++ b/spec/nim/texpr_sizeof_value_sized.nim
@@ -6,8 +6,8 @@ import auxiliary/test_utils
 
 let r = ExprSizeofValueSized.fromFile("src/fixed_struct.bin")
 
-assert r.selfSizeof == int((12 + 2))
-assert r.sizeofBlock == int(12)
-assert r.sizeofBlockA == int(1)
-assert r.sizeofBlockB == int(4)
-assert r.sizeofBlockC == int(2)
+assert r.selfSizeof == (12 + 2)
+assert r.sizeofBlock == 12
+assert r.sizeofBlockA == 1
+assert r.sizeofBlockB == 4
+assert r.sizeofBlockC == 2
diff --git a/spec/nim/texpr_str_encodings.nim b/spec/nim/texpr_str_encodings.nim
index 29ad7c543..90cbd6a2d 100644
--- a/spec/nim/texpr_str_encodings.nim
+++ b/spec/nim/texpr_str_encodings.nim
@@ -6,10 +6,10 @@ import auxiliary/test_utils
 
 let r = ExprStrEncodings.fromFile("src/str_encodings.bin")
 
-assert r.str1Eq == bool(true)
-assert r.str2Eq == bool(true)
-assert r.str3Eq == bool(true)
-assert r.str3EqStr2 == bool(true)
-assert r.str4Eq == bool(true)
-assert r.str4GtStrCalc == bool(true)
-assert r.str4GtStrFromBytes == bool(true)
+assert r.str1Eq == true
+assert r.str2Eq == true
+assert r.str3Eq == true
+assert r.str3EqStr2 == true
+assert r.str4Eq == true
+assert r.str4GtStrCalc == true
+assert r.str4GtStrFromBytes == true
diff --git a/spec/nim/texpr_str_ops.nim b/spec/nim/texpr_str_ops.nim
index 8c59d413b..b530e23ab 100644
--- a/spec/nim/texpr_str_ops.nim
+++ b/spec/nim/texpr_str_ops.nim
@@ -6,20 +6,20 @@ import auxiliary/test_utils
 
 let r = ExprStrOps.fromFile("src/term_strz.bin")
 
-assert r.one == string("foo|b")
-assert r.oneLen == int(5)
-assert r.oneRev == string("b|oof")
-assert r.oneSubstr0To3 == string("foo")
-assert r.oneSubstr2To5 == string("o|b")
-assert r.oneSubstr3To3 == string("")
-assert r.two == string("0123456789")
-assert r.twoLen == int(10)
-assert r.twoRev == string("9876543210")
-assert r.twoSubstr0To7 == string("0123456")
-assert r.twoSubstr4To10 == string("456789")
-assert r.twoSubstr0To10 == string("0123456789")
-assert r.toIAttr == int(9173)
-assert r.toIR10 == int(-72)
-assert r.toIR2 == int(86)
-assert r.toIR8 == int(465)
-assert r.toIR16 == int(18383)
+assert r.one == "foo|b"
+assert r.oneLen == 5
+assert r.oneRev == "b|oof"
+assert r.oneSubstr0To3 == "foo"
+assert r.oneSubstr2To5 == "o|b"
+assert r.oneSubstr3To3 == ""
+assert r.two == "0123456789"
+assert r.twoLen == 10
+assert r.twoRev == "9876543210"
+assert r.twoSubstr0To7 == "0123456"
+assert r.twoSubstr4To10 == "456789"
+assert r.twoSubstr0To10 == "0123456789"
+assert r.toIAttr == 9173
+assert r.toIR10 == -72
+assert r.toIR2 == 86
+assert r.toIR8 == 465
+assert r.toIR16 == 18383
diff --git a/spec/nim/tfixed_struct.nim b/spec/nim/tfixed_struct.nim
index a724e192a..234f28201 100644
--- a/spec/nim/tfixed_struct.nim
+++ b/spec/nim/tfixed_struct.nim
@@ -6,23 +6,23 @@ import auxiliary/test_utils
 
 let r = FixedStruct.fromFile("src/fixed_struct.bin")
 
-assert r.hdr.uint8 == uint8(255)
-assert r.hdr.uint16 == uint16(65535)
-assert r.hdr.uint32 == uint32(4294967295'i64)
-assert r.hdr.uint64 == uint64(18446744073709551615'u64)
-assert r.hdr.sint8 == int8(-1)
-assert r.hdr.sint16 == int16(-1)
-assert r.hdr.sint32 == int32(-1)
-assert r.hdr.sint64 == int64(-1)
-assert r.hdr.uint16le == uint16(66)
-assert r.hdr.uint32le == uint32(66)
-assert r.hdr.uint64le == uint64(66)
-assert r.hdr.sint16le == int16(-66)
-assert r.hdr.sint32le == int32(-66)
-assert r.hdr.sint64le == int64(-66)
-assert r.hdr.uint16be == uint16(66)
-assert r.hdr.uint32be == uint32(66)
-assert r.hdr.uint64be == uint64(66)
-assert r.hdr.sint16be == int16(-66)
-assert r.hdr.sint32be == int32(-66)
-assert r.hdr.sint64be == int64(-66)
+assert r.hdr.uint8 == 255
+assert r.hdr.uint16 == 65535
+assert r.hdr.uint32 == 4294967295'i64
+assert r.hdr.uint64 == 18446744073709551615'u64
+assert r.hdr.sint8 == -1
+assert r.hdr.sint16 == -1
+assert r.hdr.sint32 == -1
+assert r.hdr.sint64 == -1
+assert r.hdr.uint16le == 66
+assert r.hdr.uint32le == 66
+assert r.hdr.uint64le == 66
+assert r.hdr.sint16le == -66
+assert r.hdr.sint32le == -66
+assert r.hdr.sint64le == -66
+assert r.hdr.uint16be == 66
+assert r.hdr.uint32be == 66
+assert r.hdr.uint64be == 66
+assert r.hdr.sint16be == -66
+assert r.hdr.sint32be == -66
+assert r.hdr.sint64be == -66
diff --git a/spec/nim/tfloat_to_i.nim b/spec/nim/tfloat_to_i.nim
index 6ca299752..629a20f3c 100644
--- a/spec/nim/tfloat_to_i.nim
+++ b/spec/nim/tfloat_to_i.nim
@@ -6,11 +6,11 @@ import auxiliary/test_utils
 
 let r = FloatToI.fromFile("src/floating_points.bin")
 
-assert r.singleValue == float32(0.5)
-assert r.doubleValue == float64(0.25)
-assert r.singleI == int(0)
-assert r.doubleI == int(0)
-assert r.float1I == int(1)
-assert r.float2I == int(1)
-assert r.float3I == int(1)
-assert r.float4I == int(-2)
+assert r.singleValue == 0.5
+assert r.doubleValue == 0.25
+assert r.singleI == 0
+assert r.doubleI == 0
+assert r.float1I == 1
+assert r.float2I == 1
+assert r.float3I == 1
+assert r.float4I == -2
diff --git a/spec/nim/tfloating_points.nim b/spec/nim/tfloating_points.nim
index ff99b22ff..61976ed99 100644
--- a/spec/nim/tfloating_points.nim
+++ b/spec/nim/tfloating_points.nim
@@ -6,11 +6,11 @@ import auxiliary/test_utils
 
 let r = FloatingPoints.fromFile("src/floating_points.bin")
 
-assert r.singleValue == float32((float32(0.5)))
-assert r.singleValueBe == float32((float32(0.5)))
-assert r.doubleValue == float64(0.25)
-assert r.doubleValueBe == float64(0.25)
-assert r.approximateValue == float32(1.2345)
-assert r.singleValuePlusInt == float64(1.5)
-assert r.singleValuePlusFloat == float64(1.0)
-assert r.doubleValuePlusFloat == float64(0.3)
+assert r.singleValue == (float32(0.5))
+assert r.singleValueBe == (float32(0.5))
+assert r.doubleValue == 0.25
+assert r.doubleValueBe == 0.25
+assert r.approximateValue == 1.2345
+assert r.singleValuePlusInt == 1.5
+assert r.singleValuePlusFloat == 1.0
+assert r.doubleValuePlusFloat == 0.3
diff --git a/spec/nim/thello_world.nim b/spec/nim/thello_world.nim
index 7b5700f2b..ca3a6cfaf 100644
--- a/spec/nim/thello_world.nim
+++ b/spec/nim/thello_world.nim
@@ -6,4 +6,4 @@ import auxiliary/test_utils
 
 let r = HelloWorld.fromFile("src/fixed_struct.bin")
 
-assert r.one == uint8(80)
+assert r.one == 80
diff --git a/spec/nim/tif_struct.nim b/spec/nim/tif_struct.nim
index d79b18c71..42fd043ae 100644
--- a/spec/nim/tif_struct.nim
+++ b/spec/nim/tif_struct.nim
@@ -6,10 +6,10 @@ import auxiliary/test_utils
 
 let r = IfStruct.fromFile("src/if_struct.bin")
 
-assert r.op1.opcode == uint8(83)
-assert r.op1.argStr.str == string("foo")
-assert r.op2.opcode == uint8(84)
-assert r.op2.argTuple.num1 == uint8(66)
-assert r.op2.argTuple.num2 == uint8(67)
-assert r.op3.opcode == uint8(83)
-assert r.op3.argStr.str == string("bar")
+assert r.op1.opcode == 83
+assert r.op1.argStr.str == "foo"
+assert r.op2.opcode == 84
+assert r.op2.argTuple.num1 == 66
+assert r.op2.argTuple.num2 == 67
+assert r.op3.opcode == 83
+assert r.op3.argStr.str == "bar"
diff --git a/spec/nim/tif_values.nim b/spec/nim/tif_values.nim
index cd931fc09..8984e037a 100644
--- a/spec/nim/tif_values.nim
+++ b/spec/nim/tif_values.nim
@@ -6,9 +6,9 @@ import auxiliary/test_utils
 
 let r = IfValues.fromFile("src/fixed_struct.bin")
 
-assert r.codes[0].opcode == uint8(80)
-assert r.codes[0].halfOpcode == int(40)
-assert r.codes[1].opcode == uint8(65)
+assert r.codes[0].opcode == 80
+assert r.codes[0].halfOpcode == 40
+assert r.codes[1].opcode == 65
 assert r.codes[1].halfOpcode == 0
-assert r.codes[2].opcode == uint8(67)
+assert r.codes[2].opcode == 67
 assert r.codes[2].halfOpcode == 0
diff --git a/spec/nim/timports0.nim b/spec/nim/timports0.nim
index 1f6985af1..5db6320d5 100644
--- a/spec/nim/timports0.nim
+++ b/spec/nim/timports0.nim
@@ -7,6 +7,6 @@ import auxiliary/test_utils
 
 let r = Imports0.fromFile("src/fixed_struct.bin")
 
-assert r.two == uint8(80)
-assert r.hw.one == uint8(65)
-assert r.hwOne == uint8(65)
+assert r.two == 80
+assert r.hw.one == 65
+assert r.hwOne == 65
diff --git a/spec/nim/timports_abs.nim b/spec/nim/timports_abs.nim
index 5d1a15b0e..d41c3349e 100644
--- a/spec/nim/timports_abs.nim
+++ b/spec/nim/timports_abs.nim
@@ -7,5 +7,5 @@ import auxiliary/test_utils
 
 let r = ImportsAbs.fromFile("src/fixed_struct.bin")
 
-assert r.len.value == int(80)
-assert len(r.body) == int(80)
+assert r.len.value == 80
+assert len(r.body) == 80
diff --git a/spec/nim/timports_circular_a.nim b/spec/nim/timports_circular_a.nim
index 4f13cfa3d..0fdacd0a2 100644
--- a/spec/nim/timports_circular_a.nim
+++ b/spec/nim/timports_circular_a.nim
@@ -7,8 +7,8 @@ import auxiliary/test_utils
 
 let r = ImportsCircularA.fromFile("src/fixed_struct.bin")
 
-assert r.code == uint8(80)
-assert r.two.initial == uint8(65)
-assert r.two.backRef.code == uint8(67)
-assert r.two.backRef.two.initial == uint8(75)
+assert r.code == 80
+assert r.two.initial == 65
+assert r.two.backRef.code == 67
+assert r.two.backRef.two.initial == 75
 assert r.two.backRef.two.backRef == nil
diff --git a/spec/nim/timports_rel_1.nim b/spec/nim/timports_rel_1.nim
index 630e63d0c..dc14d959d 100644
--- a/spec/nim/timports_rel_1.nim
+++ b/spec/nim/timports_rel_1.nim
@@ -8,6 +8,6 @@ import auxiliary/test_utils
 
 let r = ImportsRel1.fromFile("src/fixed_struct.bin")
 
-assert r.one == uint8(80)
-assert r.two.one == uint8(65)
-assert r.two.two.one == uint8(67)
+assert r.one == 80
+assert r.two.one == 65
+assert r.two.two.one == 67
diff --git a/spec/nim/tindex_sizes.nim b/spec/nim/tindex_sizes.nim
index 9addaaf5e..1207203d7 100644
--- a/spec/nim/tindex_sizes.nim
+++ b/spec/nim/tindex_sizes.nim
@@ -6,10 +6,10 @@ import auxiliary/test_utils
 
 let r = IndexSizes.fromFile("src/index_sizes.bin")
 
-assert r.qty == uint32(3)
-assert r.sizes[0] == uint32(1)
-assert r.sizes[1] == uint32(8)
-assert r.sizes[2] == uint32(4)
-assert r.bufs[0] == string("A")
-assert r.bufs[1] == string("BBBBBBBB")
-assert r.bufs[2] == string("CCCC")
+assert r.qty == 3
+assert r.sizes[0] == 1
+assert r.sizes[1] == 8
+assert r.sizes[2] == 4
+assert r.bufs[0] == "A"
+assert r.bufs[1] == "BBBBBBBB"
+assert r.bufs[2] == "CCCC"
diff --git a/spec/nim/tindex_to_param_eos.nim b/spec/nim/tindex_to_param_eos.nim
index 15c9e1c39..c4aea35ae 100644
--- a/spec/nim/tindex_to_param_eos.nim
+++ b/spec/nim/tindex_to_param_eos.nim
@@ -6,10 +6,10 @@ import auxiliary/test_utils
 
 let r = IndexToParamEos.fromFile("src/index_sizes.bin")
 
-assert r.qty == uint32(3)
-assert r.sizes[0] == uint32(1)
-assert r.sizes[1] == uint32(8)
-assert r.sizes[2] == uint32(4)
-assert r.blocks[0].buf == string("A")
-assert r.blocks[1].buf == string("BBBBBBBB")
-assert r.blocks[2].buf == string("CCCC")
+assert r.qty == 3
+assert r.sizes[0] == 1
+assert r.sizes[1] == 8
+assert r.sizes[2] == 4
+assert r.blocks[0].buf == "A"
+assert r.blocks[1].buf == "BBBBBBBB"
+assert r.blocks[2].buf == "CCCC"
diff --git a/spec/nim/tindex_to_param_expr.nim b/spec/nim/tindex_to_param_expr.nim
index 8ef987152..650459b87 100644
--- a/spec/nim/tindex_to_param_expr.nim
+++ b/spec/nim/tindex_to_param_expr.nim
@@ -6,10 +6,10 @@ import auxiliary/test_utils
 
 let r = IndexToParamExpr.fromFile("src/index_sizes.bin")
 
-assert r.qty == uint32(3)
-assert r.sizes[0] == uint32(1)
-assert r.sizes[1] == uint32(8)
-assert r.sizes[2] == uint32(4)
-assert r.blocks[0].buf == string("A")
-assert r.blocks[1].buf == string("BBBBBBBB")
-assert r.blocks[2].buf == string("CCCC")
+assert r.qty == 3
+assert r.sizes[0] == 1
+assert r.sizes[1] == 8
+assert r.sizes[2] == 4
+assert r.blocks[0].buf == "A"
+assert r.blocks[1].buf == "BBBBBBBB"
+assert r.blocks[2].buf == "CCCC"
diff --git a/spec/nim/tindex_to_param_until.nim b/spec/nim/tindex_to_param_until.nim
index 2450f9e9f..e6cbb1e12 100644
--- a/spec/nim/tindex_to_param_until.nim
+++ b/spec/nim/tindex_to_param_until.nim
@@ -6,10 +6,10 @@ import auxiliary/test_utils
 
 let r = IndexToParamUntil.fromFile("src/index_sizes.bin")
 
-assert r.qty == uint32(3)
-assert r.sizes[0] == uint32(1)
-assert r.sizes[1] == uint32(8)
-assert r.sizes[2] == uint32(4)
-assert r.blocks[0].buf == string("A")
-assert r.blocks[1].buf == string("BBBBBBBB")
-assert r.blocks[2].buf == string("CCCC")
+assert r.qty == 3
+assert r.sizes[0] == 1
+assert r.sizes[1] == 8
+assert r.sizes[2] == 4
+assert r.blocks[0].buf == "A"
+assert r.blocks[1].buf == "BBBBBBBB"
+assert r.blocks[2].buf == "CCCC"
diff --git a/spec/nim/tinstance_io_user.nim b/spec/nim/tinstance_io_user.nim
index 26c48084c..0d51797f4 100644
--- a/spec/nim/tinstance_io_user.nim
+++ b/spec/nim/tinstance_io_user.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = InstanceIoUser.fromFile("src/instance_io.bin")
 
-assert r.qtyEntries == uint32(3)
-assert r.entries[0].name == string("the")
-assert r.entries[1].name == string("rainy")
-assert r.entries[2].name == string("day it is")
+assert r.qtyEntries == 3
+assert r.entries[0].name == "the"
+assert r.entries[1].name == "rainy"
+assert r.entries[2].name == "day it is"
diff --git a/spec/nim/tinstance_std.nim b/spec/nim/tinstance_std.nim
index 214b5fd1c..b3faea21f 100644
--- a/spec/nim/tinstance_std.nim
+++ b/spec/nim/tinstance_std.nim
@@ -6,4 +6,4 @@ import auxiliary/test_utils
 
 let r = InstanceStd.fromFile("src/str_encodings.bin")
 
-assert r.header == string("Some ")
+assert r.header == "Some "
diff --git a/spec/nim/tinstance_std_array.nim b/spec/nim/tinstance_std_array.nim
index d6373d227..4792d7f12 100644
--- a/spec/nim/tinstance_std_array.nim
+++ b/spec/nim/tinstance_std_array.nim
@@ -6,10 +6,10 @@ import auxiliary/test_utils
 
 let r = InstanceStdArray.fromFile("src/instance_std_array.bin")
 
-assert r.ofs == uint32(16)
-assert r.qtyEntries == uint32(3)
-assert r.entrySize == uint32(4)
-assert len(r.entries) == int(3)
+assert r.ofs == 16
+assert r.qtyEntries == 3
+assert r.entrySize == 4
+assert len(r.entries) == 3
 assert r.entries[0] == @[17'u8, 17'u8, 17'u8, 17'u8]
 assert r.entries[1] == @[34'u8, 34'u8, 34'u8, 34'u8]
 assert r.entries[2] == @[51'u8, 51'u8, 51'u8, 51'u8]
diff --git a/spec/nim/tinstance_user_array.nim b/spec/nim/tinstance_user_array.nim
index 1f5aa6144..215ec27d4 100644
--- a/spec/nim/tinstance_user_array.nim
+++ b/spec/nim/tinstance_user_array.nim
@@ -6,13 +6,13 @@ import auxiliary/test_utils
 
 let r = InstanceUserArray.fromFile("src/instance_std_array.bin")
 
-assert r.ofs == uint32(16)
-assert r.qtyEntries == uint32(3)
-assert r.entrySize == uint32(4)
-assert len(r.userEntries) == int(3)
-assert r.userEntries[0].word1 == uint16(4369)
-assert r.userEntries[0].word2 == uint16(4369)
-assert r.userEntries[1].word1 == uint16(8738)
-assert r.userEntries[1].word2 == uint16(8738)
-assert r.userEntries[2].word1 == uint16(13107)
-assert r.userEntries[2].word2 == uint16(13107)
+assert r.ofs == 16
+assert r.qtyEntries == 3
+assert r.entrySize == 4
+assert len(r.userEntries) == 3
+assert r.userEntries[0].word1 == 4369
+assert r.userEntries[0].word2 == 4369
+assert r.userEntries[1].word1 == 8738
+assert r.userEntries[1].word2 == 8738
+assert r.userEntries[2].word1 == 13107
+assert r.userEntries[2].word2 == 13107
diff --git a/spec/nim/tintegers.nim b/spec/nim/tintegers.nim
index 5c52a7d6e..4a2c57928 100644
--- a/spec/nim/tintegers.nim
+++ b/spec/nim/tintegers.nim
@@ -6,23 +6,23 @@ import auxiliary/test_utils
 
 let r = Integers.fromFile("src/fixed_struct.bin")
 
-assert r.uint8 == uint8(255)
-assert r.uint16 == uint16(65535)
-assert r.uint32 == uint32(4294967295'i64)
-assert r.uint64 == uint64(18446744073709551615'u64)
-assert r.sint8 == int8(-1)
-assert r.sint16 == int16(-1)
-assert r.sint32 == int32(-1)
-assert r.sint64 == int64(-1)
-assert r.uint16le == uint16(66)
-assert r.uint32le == uint32(66)
-assert r.uint64le == uint64(66)
-assert r.sint16le == int16(-66)
-assert r.sint32le == int32(-66)
-assert r.sint64le == int64(-66)
-assert r.uint16be == uint16(66)
-assert r.uint32be == uint32(66)
-assert r.uint64be == uint64(66)
-assert r.sint16be == int16(-66)
-assert r.sint32be == int32(-66)
-assert r.sint64be == int64(-66)
+assert r.uint8 == 255
+assert r.uint16 == 65535
+assert r.uint32 == 4294967295'i64
+assert r.uint64 == 18446744073709551615'u64
+assert r.sint8 == -1
+assert r.sint16 == -1
+assert r.sint32 == -1
+assert r.sint64 == -1
+assert r.uint16le == 66
+assert r.uint32le == 66
+assert r.uint64le == 66
+assert r.sint16le == -66
+assert r.sint32le == -66
+assert r.sint64le == -66
+assert r.uint16be == 66
+assert r.uint32be == 66
+assert r.uint64be == 66
+assert r.sint16be == -66
+assert r.sint32be == -66
+assert r.sint64be == -66
diff --git a/spec/nim/tintegers_double_overflow.nim b/spec/nim/tintegers_double_overflow.nim
index 3b53dff30..89d47936c 100644
--- a/spec/nim/tintegers_double_overflow.nim
+++ b/spec/nim/tintegers_double_overflow.nim
@@ -7,11 +7,11 @@ import strutils
 
 let r = IntegersDoubleOverflow.fromFile("src/integers_double_overflow.bin")
 
-assert r.signedSafeMinBe == int64(-9007199254740991'i64)
-assert r.signedSafeMinLe == int64(-9007199254740991'i64)
-assert r.signedSafeMaxBe == int64(9007199254740991'i64)
-assert r.signedSafeMaxLe == int64(9007199254740991'i64)
-assert intToStr(int(r.signedUnsafeNegBe)) == string("-9007199254740993")
-assert intToStr(int(r.signedUnsafeNegLe)) == string("-9007199254740993")
-assert intToStr(int(r.signedUnsafePosBe)) == string("9007199254740993")
-assert intToStr(int(r.signedUnsafePosBe)) == string("9007199254740993")
+assert r.signedSafeMinBe == -9007199254740991'i64
+assert r.signedSafeMinLe == -9007199254740991'i64
+assert r.signedSafeMaxBe == 9007199254740991'i64
+assert r.signedSafeMaxLe == 9007199254740991'i64
+assert intToStr(int(r.signedUnsafeNegBe)) == "-9007199254740993"
+assert intToStr(int(r.signedUnsafeNegLe)) == "-9007199254740993"
+assert intToStr(int(r.signedUnsafePosBe)) == "9007199254740993"
+assert intToStr(int(r.signedUnsafePosBe)) == "9007199254740993"
diff --git a/spec/nim/tintegers_min_max.nim b/spec/nim/tintegers_min_max.nim
index f0e158dd9..16b396745 100644
--- a/spec/nim/tintegers_min_max.nim
+++ b/spec/nim/tintegers_min_max.nim
@@ -6,31 +6,31 @@ import auxiliary/test_utils
 
 let r = IntegersMinMax.fromFile("src/integers_min_max.bin")
 
-assert r.unsignedMin.u1 == uint8(0)
-assert r.unsignedMin.u2le == uint16(0)
-assert r.unsignedMin.u4le == uint32(0)
-assert r.unsignedMin.u8le == uint64(0)
-assert r.unsignedMin.u2be == uint16(0)
-assert r.unsignedMin.u4be == uint32(0)
-assert r.unsignedMin.u8be == uint64(0)
-assert r.unsignedMax.u1 == uint8(255)
-assert r.unsignedMax.u2le == uint16(65535)
-assert r.unsignedMax.u4le == uint32(4294967295'i64)
-assert r.unsignedMax.u8le == uint64(18446744073709551615'u64)
-assert r.unsignedMax.u2be == uint16(65535)
-assert r.unsignedMax.u4be == uint32(4294967295'i64)
-assert r.unsignedMax.u8be == uint64(18446744073709551615'u64)
-assert r.signedMin.s1 == int8(-128)
-assert r.signedMin.s2le == int16(-32768)
-assert r.signedMin.s4le == int32(-2147483648'i64)
-assert r.signedMin.s8le == int64(-9223372036854775808'u64)
-assert r.signedMin.s2be == int16(-32768)
-assert r.signedMin.s4be == int32(-2147483648'i64)
-assert r.signedMin.s8be == int64(-9223372036854775808'u64)
-assert r.signedMax.s1 == int8(127)
-assert r.signedMax.s2le == int16(32767)
-assert r.signedMax.s4le == int32(2147483647)
-assert r.signedMax.s8le == int64(9223372036854775807'i64)
-assert r.signedMax.s2be == int16(32767)
-assert r.signedMax.s4be == int32(2147483647)
-assert r.signedMax.s8be == int64(9223372036854775807'i64)
+assert r.unsignedMin.u1 == 0
+assert r.unsignedMin.u2le == 0
+assert r.unsignedMin.u4le == 0
+assert r.unsignedMin.u8le == 0
+assert r.unsignedMin.u2be == 0
+assert r.unsignedMin.u4be == 0
+assert r.unsignedMin.u8be == 0
+assert r.unsignedMax.u1 == 255
+assert r.unsignedMax.u2le == 65535
+assert r.unsignedMax.u4le == 4294967295'i64
+assert r.unsignedMax.u8le == 18446744073709551615'u64
+assert r.unsignedMax.u2be == 65535
+assert r.unsignedMax.u4be == 4294967295'i64
+assert r.unsignedMax.u8be == 18446744073709551615'u64
+assert r.signedMin.s1 == -128
+assert r.signedMin.s2le == -32768
+assert r.signedMin.s4le == -2147483648'i64
+assert r.signedMin.s8le == -9223372036854775808'u64
+assert r.signedMin.s2be == -32768
+assert r.signedMin.s4be == -2147483648'i64
+assert r.signedMin.s8be == -9223372036854775808'u64
+assert r.signedMax.s1 == 127
+assert r.signedMax.s2le == 32767
+assert r.signedMax.s4le == 2147483647
+assert r.signedMax.s8le == 9223372036854775807'i64
+assert r.signedMax.s2be == 32767
+assert r.signedMax.s4be == 2147483647
+assert r.signedMax.s8be == 9223372036854775807'i64
diff --git a/spec/nim/tio_local_var.nim b/spec/nim/tio_local_var.nim
index 83a1cef61..50bbe6754 100644
--- a/spec/nim/tio_local_var.nim
+++ b/spec/nim/tio_local_var.nim
@@ -7,4 +7,4 @@ import auxiliary/test_utils
 let r = IoLocalVar.fromFile("src/full256.bin")
 
 assert r.skip == @[0'u8, 1'u8, 2'u8, 3'u8, 4'u8, 5'u8, 6'u8, 7'u8, 8'u8, 9'u8, 10'u8, 11'u8, 12'u8, 13'u8, 14'u8, 15'u8, 16'u8, 17'u8, 18'u8, 19'u8]
-assert r.followup == uint8(20)
+assert r.followup == 20
diff --git a/spec/nim/tjs_signed_right_shift.nim b/spec/nim/tjs_signed_right_shift.nim
index 1f37d5354..7da5c644f 100644
--- a/spec/nim/tjs_signed_right_shift.nim
+++ b/spec/nim/tjs_signed_right_shift.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = JsSignedRightShift.fromFile("src/fixed_struct.bin")
 
-assert r.shouldBe40000000 == int(1073741824)
-assert r.shouldBeA00000 == int(10485760)
+assert r.shouldBe40000000 == 1073741824
+assert r.shouldBeA00000 == 10485760
diff --git a/spec/nim/tmultiple_use.nim b/spec/nim/tmultiple_use.nim
index afb219c0b..7602a40df 100644
--- a/spec/nim/tmultiple_use.nim
+++ b/spec/nim/tmultiple_use.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = MultipleUse.fromFile("src/position_abs.bin")
 
-assert r.t1.firstUse.value == int32(32)
-assert r.t2.secondUse.value == int32(32)
+assert r.t1.firstUse.value == 32
+assert r.t2.secondUse.value == 32
diff --git a/spec/nim/tnav_parent.nim b/spec/nim/tnav_parent.nim
index bf7c90190..e46720175 100644
--- a/spec/nim/tnav_parent.nim
+++ b/spec/nim/tnav_parent.nim
@@ -6,8 +6,8 @@ import auxiliary/test_utils
 
 let r = NavParent.fromFile("src/nav.bin")
 
-assert r.header.qtyEntries == uint32(2)
-assert r.header.filenameLen == uint32(8)
-assert len(r.index.entries) == int(2)
-assert r.index.entries[0].filename == string("FIRST___")
-assert r.index.entries[1].filename == string("SECOND__")
+assert r.header.qtyEntries == 2
+assert r.header.filenameLen == 8
+assert len(r.index.entries) == 2
+assert r.index.entries[0].filename == "FIRST___"
+assert r.index.entries[1].filename == "SECOND__"
diff --git a/spec/nim/tnav_parent2.nim b/spec/nim/tnav_parent2.nim
index 70639ac12..690ab686d 100644
--- a/spec/nim/tnav_parent2.nim
+++ b/spec/nim/tnav_parent2.nim
@@ -6,13 +6,13 @@ import auxiliary/test_utils
 
 let r = NavParent2.fromFile("src/nav_parent2.bin")
 
-assert r.ofsTags == uint32(8)
-assert r.numTags == uint32(2)
-assert r.tags[0].name == string("RAHC")
-assert r.tags[0].ofs == uint32(32)
-assert r.tags[0].numItems == uint32(3)
-assert r.tags[0].tagContent.content == string("foo")
-assert r.tags[1].name == string("RAHC")
-assert r.tags[1].ofs == uint32(35)
-assert r.tags[1].numItems == uint32(6)
-assert r.tags[1].tagContent.content == string("barbaz")
+assert r.ofsTags == 8
+assert r.numTags == 2
+assert r.tags[0].name == "RAHC"
+assert r.tags[0].ofs == 32
+assert r.tags[0].numItems == 3
+assert r.tags[0].tagContent.content == "foo"
+assert r.tags[1].name == "RAHC"
+assert r.tags[1].ofs == 35
+assert r.tags[1].numItems == 6
+assert r.tags[1].tagContent.content == "barbaz"
diff --git a/spec/nim/tnav_parent3.nim b/spec/nim/tnav_parent3.nim
index 073b068e0..716b6154a 100644
--- a/spec/nim/tnav_parent3.nim
+++ b/spec/nim/tnav_parent3.nim
@@ -6,13 +6,13 @@ import auxiliary/test_utils
 
 let r = NavParent3.fromFile("src/nav_parent2.bin")
 
-assert r.ofsTags == uint32(8)
-assert r.numTags == uint32(2)
-assert r.tags[0].name == string("RAHC")
-assert r.tags[0].ofs == uint32(32)
-assert r.tags[0].numItems == uint32(3)
-assert r.tags[0].tagContent.content == string("foo")
-assert r.tags[1].name == string("RAHC")
-assert r.tags[1].ofs == uint32(35)
-assert r.tags[1].numItems == uint32(6)
-assert r.tags[1].tagContent.content == string("barbaz")
+assert r.ofsTags == 8
+assert r.numTags == 2
+assert r.tags[0].name == "RAHC"
+assert r.tags[0].ofs == 32
+assert r.tags[0].numItems == 3
+assert r.tags[0].tagContent.content == "foo"
+assert r.tags[1].name == "RAHC"
+assert r.tags[1].ofs == 35
+assert r.tags[1].numItems == 6
+assert r.tags[1].tagContent.content == "barbaz"
diff --git a/spec/nim/tnav_parent_false.nim b/spec/nim/tnav_parent_false.nim
index 9e357cf94..9c765bb06 100644
--- a/spec/nim/tnav_parent_false.nim
+++ b/spec/nim/tnav_parent_false.nim
@@ -6,8 +6,8 @@ import auxiliary/test_utils
 
 let r = NavParentFalse.fromFile("src/nav_parent_codes.bin")
 
-assert r.childSize == uint8(3)
-assert r.elementA.foo.code == uint8(73)
+assert r.childSize == 3
+assert r.elementA.foo.code == 73
 assert r.elementA.foo.more == @[49'u8, 50'u8, 51'u8]
-assert r.elementA.bar.foo.code == uint8(66)
-assert r.elementB.foo.code == uint8(98)
+assert r.elementA.bar.foo.code == 66
+assert r.elementB.foo.code == 98
diff --git a/spec/nim/tnav_parent_false2.nim b/spec/nim/tnav_parent_false2.nim
index b8437f5d6..c7698cf2a 100644
--- a/spec/nim/tnav_parent_false2.nim
+++ b/spec/nim/tnav_parent_false2.nim
@@ -6,4 +6,4 @@ import auxiliary/test_utils
 
 let r = NavParentFalse2.fromFile("src/fixed_struct.bin")
 
-assert r.parentless.foo == uint8(80)
+assert r.parentless.foo == 80
diff --git a/spec/nim/tnav_parent_override.nim b/spec/nim/tnav_parent_override.nim
index ce8cb8d21..52c0b12f5 100644
--- a/spec/nim/tnav_parent_override.nim
+++ b/spec/nim/tnav_parent_override.nim
@@ -6,6 +6,6 @@ import auxiliary/test_utils
 
 let r = NavParentOverride.fromFile("src/nav_parent_codes.bin")
 
-assert r.childSize == uint8(3)
+assert r.childSize == 3
 assert r.child1.data == @[73'u8, 49'u8, 50'u8]
 assert r.mediator2.child2.data == @[51'u8, 66'u8, 98'u8]
diff --git a/spec/nim/tnav_parent_switch.nim b/spec/nim/tnav_parent_switch.nim
index 90e61ee54..2f8905e45 100644
--- a/spec/nim/tnav_parent_switch.nim
+++ b/spec/nim/tnav_parent_switch.nim
@@ -6,6 +6,6 @@ import auxiliary/test_utils
 
 let r = NavParentSwitch.fromFile("src/nav_parent_switch.bin")
 
-assert r.category == uint8(1)
-assert (NavParentSwitch_Element1(r.content)).foo == uint8(66)
-assert (NavParentSwitch_Element1(r.content)).subelement.bar == uint8(255)
+assert r.category == 1
+assert (NavParentSwitch_Element1(r.content)).foo == 66
+assert (NavParentSwitch_Element1(r.content)).subelement.bar == 255
diff --git a/spec/nim/tnav_parent_switch_cast.nim b/spec/nim/tnav_parent_switch_cast.nim
index 0240622d5..2fbece8e7 100644
--- a/spec/nim/tnav_parent_switch_cast.nim
+++ b/spec/nim/tnav_parent_switch_cast.nim
@@ -6,6 +6,6 @@ import auxiliary/test_utils
 
 let r = NavParentSwitchCast.fromFile("src/switch_integers.bin")
 
-assert r.main.bufType == uint8(1)
-assert r.main.flag == uint8(7)
-assert (NavParentSwitchCast_Foo_One(r.main.buf)).branch.flag == uint8(7)
+assert r.main.bufType == 1
+assert r.main.flag == 7
+assert (NavParentSwitchCast_Foo_One(r.main.buf)).branch.flag == 7
diff --git a/spec/nim/tnav_parent_vs_value_inst.nim b/spec/nim/tnav_parent_vs_value_inst.nim
index bb7be2726..aaa9a2919 100644
--- a/spec/nim/tnav_parent_vs_value_inst.nim
+++ b/spec/nim/tnav_parent_vs_value_inst.nim
@@ -6,4 +6,4 @@ import auxiliary/test_utils
 
 let r = NavParentVsValueInst.fromFile("src/term_strz.bin")
 
-assert r.s1 == string("foo")
+assert r.s1 == "foo"
diff --git a/spec/nim/tnav_root.nim b/spec/nim/tnav_root.nim
index da1f799e3..f0ea6ad21 100644
--- a/spec/nim/tnav_root.nim
+++ b/spec/nim/tnav_root.nim
@@ -6,8 +6,8 @@ import auxiliary/test_utils
 
 let r = NavRoot.fromFile("src/nav.bin")
 
-assert r.header.qtyEntries == uint32(2)
-assert r.header.filenameLen == uint32(8)
-assert len(r.index.entries) == int(2)
-assert r.index.entries[0].filename == string("FIRST___")
-assert r.index.entries[1].filename == string("SECOND__")
+assert r.header.qtyEntries == 2
+assert r.header.filenameLen == 8
+assert len(r.index.entries) == 2
+assert r.index.entries[0].filename == "FIRST___"
+assert r.index.entries[1].filename == "SECOND__"
diff --git a/spec/nim/tnested_same_name.nim b/spec/nim/tnested_same_name.nim
index fdc440e1c..95d51c240 100644
--- a/spec/nim/tnested_same_name.nim
+++ b/spec/nim/tnested_same_name.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = NestedSameName.fromFile("src/repeat_n_struct.bin")
 
-assert r.mainData.mainSize == int32(2)
+assert r.mainData.mainSize == 2
 assert r.mainData.foo.data == @[16'u8, 0'u8, 0'u8, 0'u8]
diff --git a/spec/nim/tnested_same_name2.nim b/spec/nim/tnested_same_name2.nim
index a357a1db2..b39076953 100644
--- a/spec/nim/tnested_same_name2.nim
+++ b/spec/nim/tnested_same_name2.nim
@@ -6,8 +6,8 @@ import auxiliary/test_utils
 
 let r = NestedSameName2.fromFile("src/nested_same_name2.bin")
 
-assert r.version == uint32(66)
-assert r.mainData.mainSize == int32(2)
+assert r.version == 66
+assert r.mainData.mainSize == 2
 assert r.mainData.foo.data1 == @[17'u8, 17'u8, 17'u8, 17'u8]
-assert r.dummy.dummySize == int32(3)
+assert r.dummy.dummySize == 3
 assert r.dummy.foo.data2 == @[34'u8, 34'u8, 34'u8, 34'u8, 34'u8, 34'u8]
diff --git a/spec/nim/tnested_type_param.nim b/spec/nim/tnested_type_param.nim
index d93eb639a..60db5fbc2 100644
--- a/spec/nim/tnested_type_param.nim
+++ b/spec/nim/tnested_type_param.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = NestedTypeParam.fromFile("src/term_strz.bin")
 
-assert r.mainSeq.myLen == uint32(5)
-assert r.mainSeq.body == string("foo|b")
+assert r.mainSeq.myLen == 5
+assert r.mainSeq.body == "foo|b"
diff --git a/spec/nim/tnested_types.nim b/spec/nim/tnested_types.nim
index 5443a6742..cfdb8ceaf 100644
--- a/spec/nim/tnested_types.nim
+++ b/spec/nim/tnested_types.nim
@@ -6,6 +6,6 @@ import auxiliary/test_utils
 
 let r = NestedTypes.fromFile("src/fixed_struct.bin")
 
-assert r.one.typedAtRoot.valueB == int8(80)
-assert r.one.typedHere.valueC == int8(65)
-assert r.two.valueB == int8(67)
+assert r.one.typedAtRoot.valueB == 80
+assert r.one.typedHere.valueC == 65
+assert r.two.valueB == 67
diff --git a/spec/nim/tnested_types2.nim b/spec/nim/tnested_types2.nim
index 4c8d41a77..d0eb71836 100644
--- a/spec/nim/tnested_types2.nim
+++ b/spec/nim/tnested_types2.nim
@@ -6,10 +6,10 @@ import auxiliary/test_utils
 
 let r = NestedTypes2.fromFile("src/fixed_struct.bin")
 
-assert r.one.typedAtRoot.valueB == int8(80)
-assert r.one.typedHere1.valueC == int8(65)
-assert r.one.typedHere1.typedHere.valueD == int8(67)
-assert r.one.typedHere1.typedParent.valueCc == int8(75)
-assert r.one.typedHere1.typedRoot.valueB == int8(45)
-assert r.one.typedHere2.valueCc == int8(49)
-assert r.two.valueB == int8(-1)
+assert r.one.typedAtRoot.valueB == 80
+assert r.one.typedHere1.valueC == 65
+assert r.one.typedHere1.typedHere.valueD == 67
+assert r.one.typedHere1.typedParent.valueCc == 75
+assert r.one.typedHere1.typedRoot.valueB == 45
+assert r.one.typedHere2.valueCc == 49
+assert r.two.valueB == -1
diff --git a/spec/nim/tnested_types3.nim b/spec/nim/tnested_types3.nim
index 0d81f08d0..683e21baa 100644
--- a/spec/nim/tnested_types3.nim
+++ b/spec/nim/tnested_types3.nim
@@ -6,8 +6,8 @@ import auxiliary/test_utils
 
 let r = NestedTypes3.fromFile("src/fixed_struct.bin")
 
-assert r.aCc.valueCc == int8(80)
-assert r.aCD.valueD == int8(65)
-assert r.b.valueB == int8(67)
-assert r.b.aCc.valueCc == int8(75)
-assert r.b.aCD.valueD == int8(45)
+assert r.aCc.valueCc == 80
+assert r.aCD.valueD == 65
+assert r.b.valueB == 67
+assert r.b.aCc.valueCc == 75
+assert r.b.aCD.valueD == 45
diff --git a/spec/nim/tnon_standard.nim b/spec/nim/tnon_standard.nim
index 6db2915f7..a8aa3c005 100644
--- a/spec/nim/tnon_standard.nim
+++ b/spec/nim/tnon_standard.nim
@@ -6,4 +6,4 @@ import auxiliary/test_utils
 
 let r = NonStandard.fromFile("src/fixed_struct.bin")
 
-assert r.foo == uint8(80)
+assert r.foo == 80
diff --git a/spec/nim/tparams_call_extra_parens.nim b/spec/nim/tparams_call_extra_parens.nim
index 89ae157c5..afe973a13 100644
--- a/spec/nim/tparams_call_extra_parens.nim
+++ b/spec/nim/tparams_call_extra_parens.nim
@@ -6,4 +6,4 @@ import auxiliary/test_utils
 
 let r = ParamsCallExtraParens.fromFile("src/term_strz.bin")
 
-assert r.buf1.body == string("foo|b")
+assert r.buf1.body == "foo|b"
diff --git a/spec/nim/tparams_call_short.nim b/spec/nim/tparams_call_short.nim
index 9eac6647b..d62f533bf 100644
--- a/spec/nim/tparams_call_short.nim
+++ b/spec/nim/tparams_call_short.nim
@@ -6,6 +6,6 @@ import auxiliary/test_utils
 
 let r = ParamsCallShort.fromFile("src/term_strz.bin")
 
-assert r.buf1.body == string("foo|b")
-assert r.buf2.body == string("ar|ba")
-assert r.buf2.trailer == uint8(122)
+assert r.buf1.body == "foo|b"
+assert r.buf2.body == "ar|ba"
+assert r.buf2.trailer == 122
diff --git a/spec/nim/tparams_enum.nim b/spec/nim/tparams_enum.nim
index 15534bc9b..98847ad82 100644
--- a/spec/nim/tparams_enum.nim
+++ b/spec/nim/tparams_enum.nim
@@ -7,4 +7,4 @@ import auxiliary/test_utils
 let r = ParamsEnum.fromFile("src/enum_0.bin")
 
 assert r.one == params_enum.cat
-assert r.invokeWithParam.isCat == bool(true)
+assert r.invokeWithParam.isCat == true
diff --git a/spec/nim/tparams_pass_array_int.nim b/spec/nim/tparams_pass_array_int.nim
index a76c297ba..cf5b64726 100644
--- a/spec/nim/tparams_pass_array_int.nim
+++ b/spec/nim/tparams_pass_array_int.nim
@@ -6,10 +6,10 @@ import auxiliary/test_utils
 
 let r = ParamsPassArrayInt.fromFile("src/position_to_end.bin")
 
-assert len(r.passInts.nums) == int(3)
-assert r.passInts.nums[0] == uint16(513)
-assert r.passInts.nums[1] == uint16(1027)
-assert r.passInts.nums[2] == uint16(1541)
-assert len(r.passIntsCalc.nums) == int(2)
-assert r.passIntsCalc.nums[0] == uint16(27643)
-assert r.passIntsCalc.nums[1] == uint16(7)
+assert len(r.passInts.nums) == 3
+assert r.passInts.nums[0] == 513
+assert r.passInts.nums[1] == 1027
+assert r.passInts.nums[2] == 1541
+assert len(r.passIntsCalc.nums) == 2
+assert r.passIntsCalc.nums[0] == 27643
+assert r.passIntsCalc.nums[1] == 7
diff --git a/spec/nim/tparams_pass_array_str.nim b/spec/nim/tparams_pass_array_str.nim
index 420f5ee44..c729fca01 100644
--- a/spec/nim/tparams_pass_array_str.nim
+++ b/spec/nim/tparams_pass_array_str.nim
@@ -6,10 +6,10 @@ import auxiliary/test_utils
 
 let r = ParamsPassArrayStr.fromFile("src/term_strz.bin")
 
-assert len(r.passStrArray.strs) == int(3)
-assert r.passStrArray.strs[0] == string("fo")
-assert r.passStrArray.strs[1] == string("o|")
-assert r.passStrArray.strs[2] == string("ba")
-assert len(r.passStrArrayCalc.strs) == int(2)
-assert r.passStrArrayCalc.strs[0] == string("aB")
-assert r.passStrArrayCalc.strs[1] == string("Cd")
+assert len(r.passStrArray.strs) == 3
+assert r.passStrArray.strs[0] == "fo"
+assert r.passStrArray.strs[1] == "o|"
+assert r.passStrArray.strs[2] == "ba"
+assert len(r.passStrArrayCalc.strs) == 2
+assert r.passStrArrayCalc.strs[0] == "aB"
+assert r.passStrArrayCalc.strs[1] == "Cd"
diff --git a/spec/nim/tparams_pass_array_struct.nim b/spec/nim/tparams_pass_array_struct.nim
index 1a26ea98a..5f62dd2d5 100644
--- a/spec/nim/tparams_pass_array_struct.nim
+++ b/spec/nim/tparams_pass_array_struct.nim
@@ -6,6 +6,6 @@ import auxiliary/test_utils
 
 let r = ParamsPassArrayStruct.fromFile("src/position_to_end.bin")
 
-assert len(r.passStructs.structs) == int(2)
-assert (ParamsPassArrayStruct_Foo(r.passStructs.structs[0])).f == uint8(1)
-assert (ParamsPassArrayStruct_Bar(r.passStructs.structs[1])).b == uint8(2)
+assert len(r.passStructs.structs) == 2
+assert (ParamsPassArrayStruct_Foo(r.passStructs.structs[0])).f == 1
+assert (ParamsPassArrayStruct_Bar(r.passStructs.structs[1])).b == 2
diff --git a/spec/nim/tparams_pass_array_usertype.nim b/spec/nim/tparams_pass_array_usertype.nim
index 6ab219cdb..ae7a550d8 100644
--- a/spec/nim/tparams_pass_array_usertype.nim
+++ b/spec/nim/tparams_pass_array_usertype.nim
@@ -6,8 +6,8 @@ import auxiliary/test_utils
 
 let r = ParamsPassArrayUsertype.fromFile("src/position_to_end.bin")
 
-assert len(r.passBlocks.bar) == int(2)
-assert r.passBlocks.bar[0].foo == uint8(1)
-assert r.passBlocks.bar[1].foo == uint8(2)
+assert len(r.passBlocks.bar) == 2
+assert r.passBlocks.bar[0].foo == 1
+assert r.passBlocks.bar[1].foo == 2
 assert r.passBlocks.one == @[3'u8]
 assert r.passBlocks.two == @[4'u8, 5'u8]
diff --git a/spec/nim/tparams_pass_bool.nim b/spec/nim/tparams_pass_bool.nim
index 8e8723b44..3afd04979 100644
--- a/spec/nim/tparams_pass_bool.nim
+++ b/spec/nim/tparams_pass_bool.nim
@@ -6,17 +6,17 @@ import auxiliary/test_utils
 
 let r = ParamsPassBool.fromFile("src/term_strz.bin")
 
-assert r.sFalse == bool(false)
-assert r.sTrue == bool(true)
-assert r.seqB1.arg == bool(true)
-assert len(r.seqB1.foo) == int(1)
-assert r.seqBool.arg == bool(false)
-assert len(r.seqBool.foo) == int(2)
-assert r.literalB1.arg == bool(false)
-assert len(r.literalB1.foo) == int(2)
-assert r.literalBool.arg == bool(true)
-assert len(r.literalBool.foo) == int(1)
-assert r.instB1.arg == bool(true)
-assert len(r.instB1.foo) == int(1)
-assert r.instBool.arg == bool(false)
-assert len(r.instBool.foo) == int(2)
+assert r.sFalse == false
+assert r.sTrue == true
+assert r.seqB1.arg == true
+assert len(r.seqB1.foo) == 1
+assert r.seqBool.arg == false
+assert len(r.seqBool.foo) == 2
+assert r.literalB1.arg == false
+assert len(r.literalB1.foo) == 2
+assert r.literalBool.arg == true
+assert len(r.literalBool.foo) == 1
+assert r.instB1.arg == true
+assert len(r.instB1.foo) == 1
+assert r.instBool.arg == false
+assert len(r.instBool.foo) == 2
diff --git a/spec/nim/tparams_pass_struct.nim b/spec/nim/tparams_pass_struct.nim
index e8ed521a7..e8abdd71a 100644
--- a/spec/nim/tparams_pass_struct.nim
+++ b/spec/nim/tparams_pass_struct.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = ParamsPassStruct.fromFile("src/enum_negative.bin")
 
-assert r.first.foo == uint8(255)
-assert r.one.bar.qux == uint8(1)
-assert (ParamsPassStruct_Block(r.one.foo)).foo == uint8(255)
-assert (ParamsPassStruct_Block(r.one.bar.foo)).foo == uint8(255)
+assert r.first.foo == 255
+assert r.one.bar.qux == 1
+assert (ParamsPassStruct_Block(r.one.foo)).foo == 255
+assert (ParamsPassStruct_Block(r.one.bar.foo)).foo == 255
diff --git a/spec/nim/tparams_pass_usertype.nim b/spec/nim/tparams_pass_usertype.nim
index dba909b4c..3298a1bed 100644
--- a/spec/nim/tparams_pass_usertype.nim
+++ b/spec/nim/tparams_pass_usertype.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = ParamsPassUsertype.fromFile("src/position_in_seq.bin")
 
-assert r.first.foo == uint8(1)
+assert r.first.foo == 1
 assert r.one.buf == @[2'u8]
diff --git a/spec/nim/tposition_abs.nim b/spec/nim/tposition_abs.nim
index 618eb03d2..0760019e2 100644
--- a/spec/nim/tposition_abs.nim
+++ b/spec/nim/tposition_abs.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = PositionAbs.fromFile("src/position_abs.bin")
 
-assert r.indexOffset == uint32(32)
-assert r.index.entry == string("foo")
+assert r.indexOffset == 32
+assert r.index.entry == "foo"
diff --git a/spec/nim/tposition_to_end.nim b/spec/nim/tposition_to_end.nim
index 35f823150..3a7543266 100644
--- a/spec/nim/tposition_to_end.nim
+++ b/spec/nim/tposition_to_end.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = PositionToEnd.fromFile("src/position_to_end.bin")
 
-assert r.index.foo == uint32(66)
-assert r.index.bar == uint32(4660)
+assert r.index.foo == 66
+assert r.index.bar == 4660
diff --git a/spec/nim/tprocess_coerce_bytes.nim b/spec/nim/tprocess_coerce_bytes.nim
index 757147fb9..48b1ca7d0 100644
--- a/spec/nim/tprocess_coerce_bytes.nim
+++ b/spec/nim/tprocess_coerce_bytes.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = ProcessCoerceBytes.fromFile("src/process_coerce_bytes.bin")
 
-assert r.records[0].flag == uint8(0)
+assert r.records[0].flag == 0
 assert r.records[0].buf == @[65'u8, 65'u8, 65'u8, 65'u8]
-assert r.records[1].flag == uint8(1)
+assert r.records[1].flag == 1
 assert r.records[1].buf == @[66'u8, 66'u8, 66'u8, 66'u8]
diff --git a/spec/nim/tprocess_coerce_switch.nim b/spec/nim/tprocess_coerce_switch.nim
index a96dee331..7ad2c0295 100644
--- a/spec/nim/tprocess_coerce_switch.nim
+++ b/spec/nim/tprocess_coerce_switch.nim
@@ -6,6 +6,6 @@ import auxiliary/test_utils
 
 let r = ProcessCoerceSwitch.fromFile("src/process_coerce_switch.bin")
 
-assert r.bufType == uint8(0)
-assert r.flag == uint8(0)
+assert r.bufType == 0
+assert r.flag == 0
 assert (ProcessCoerceSwitch_Foo(r.buf)).bar == @[65'u8, 65'u8, 65'u8, 65'u8]
diff --git a/spec/nim/tprocess_coerce_usertype1.nim b/spec/nim/tprocess_coerce_usertype1.nim
index b67f3ac85..a46621359 100644
--- a/spec/nim/tprocess_coerce_usertype1.nim
+++ b/spec/nim/tprocess_coerce_usertype1.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = ProcessCoerceUsertype1.fromFile("src/process_coerce_bytes.bin")
 
-assert r.records[0].flag == uint8(0)
-assert r.records[0].buf.value == uint32(1094795585)
-assert r.records[1].flag == uint8(1)
-assert r.records[1].buf.value == uint32(1111638594)
+assert r.records[0].flag == 0
+assert r.records[0].buf.value == 1094795585
+assert r.records[1].flag == 1
+assert r.records[1].buf.value == 1111638594
diff --git a/spec/nim/tprocess_coerce_usertype2.nim b/spec/nim/tprocess_coerce_usertype2.nim
index ce246926a..58060a840 100644
--- a/spec/nim/tprocess_coerce_usertype2.nim
+++ b/spec/nim/tprocess_coerce_usertype2.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = ProcessCoerceUsertype2.fromFile("src/process_coerce_bytes.bin")
 
-assert r.records[0].flag == uint8(0)
-assert r.records[0].buf.value == uint32(1094795585)
-assert r.records[1].flag == uint8(1)
-assert r.records[1].buf.value == uint32(1111638594)
+assert r.records[0].flag == 0
+assert r.records[0].buf.value == 1094795585
+assert r.records[1].flag == 1
+assert r.records[1].buf.value == 1111638594
diff --git a/spec/nim/tprocess_repeat_usertype.nim b/spec/nim/tprocess_repeat_usertype.nim
index 3e2af3a30..236ab404c 100644
--- a/spec/nim/tprocess_repeat_usertype.nim
+++ b/spec/nim/tprocess_repeat_usertype.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = ProcessRepeatUsertype.fromFile("src/process_xor_4.bin")
 
-assert r.blocks[0].a == int32(-1975704206)
-assert r.blocks[0].b == int8(20)
-assert r.blocks[1].a == int32(279597642)
-assert r.blocks[1].b == int8(68)
+assert r.blocks[0].a == -1975704206
+assert r.blocks[0].b == 20
+assert r.blocks[1].a == 279597642
+assert r.blocks[1].b == 68
diff --git a/spec/nim/tprocess_to_user.nim b/spec/nim/tprocess_to_user.nim
index 80ab5b13a..c1397dea7 100644
--- a/spec/nim/tprocess_to_user.nim
+++ b/spec/nim/tprocess_to_user.nim
@@ -6,4 +6,4 @@ import auxiliary/test_utils
 
 let r = ProcessToUser.fromFile("src/process_rotate.bin")
 
-assert r.buf1.str == string("Hello")
+assert r.buf1.str == "Hello"
diff --git a/spec/nim/tprocess_xor_const.nim b/spec/nim/tprocess_xor_const.nim
index 531d0a766..e8c15be18 100644
--- a/spec/nim/tprocess_xor_const.nim
+++ b/spec/nim/tprocess_xor_const.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = ProcessXorConst.fromFile("src/process_xor_1.bin")
 
-assert r.key == uint8(255)
+assert r.key == 255
 assert r.buf == @[102'u8, 111'u8, 111'u8, 32'u8, 98'u8, 97'u8, 114'u8]
diff --git a/spec/nim/tprocess_xor_value.nim b/spec/nim/tprocess_xor_value.nim
index 541495bd8..1d149f170 100644
--- a/spec/nim/tprocess_xor_value.nim
+++ b/spec/nim/tprocess_xor_value.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = ProcessXorValue.fromFile("src/process_xor_1.bin")
 
-assert r.key == uint8(255)
+assert r.key == 255
 assert r.buf == @[102'u8, 111'u8, 111'u8, 32'u8, 98'u8, 97'u8, 114'u8]
diff --git a/spec/nim/trecursive_one.nim b/spec/nim/trecursive_one.nim
index 6f5fdd80b..0e5414a0c 100644
--- a/spec/nim/trecursive_one.nim
+++ b/spec/nim/trecursive_one.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = RecursiveOne.fromFile("src/fixed_struct.bin")
 
-assert r.one == uint8(80)
-assert (RecursiveOne(r.next)).one == uint8(65)
-assert (RecursiveOne((RecursiveOne(r.next)).next)).one == uint8(67)
-assert (RecursiveOne_Fini((RecursiveOne((RecursiveOne(r.next)).next)).next)).finisher == uint16(11595)
+assert r.one == 80
+assert (RecursiveOne(r.next)).one == 65
+assert (RecursiveOne((RecursiveOne(r.next)).next)).one == 67
+assert (RecursiveOne_Fini((RecursiveOne((RecursiveOne(r.next)).next)).next)).finisher == 11595
diff --git a/spec/nim/trepeat_eos_bit.nim b/spec/nim/trepeat_eos_bit.nim
index d30de7cbb..f5c1de2d7 100644
--- a/spec/nim/trepeat_eos_bit.nim
+++ b/spec/nim/trepeat_eos_bit.nim
@@ -6,4 +6,4 @@ import auxiliary/test_utils
 
 let r = RepeatEosBit.fromFile("src/enum_0.bin")
 
-assert len(r.nibbles) == int(16)
+assert len(r.nibbles) == 16
diff --git a/spec/nim/trepeat_eos_struct.nim b/spec/nim/trepeat_eos_struct.nim
index 2e3ef582d..c610280a6 100644
--- a/spec/nim/trepeat_eos_struct.nim
+++ b/spec/nim/trepeat_eos_struct.nim
@@ -6,8 +6,8 @@ import auxiliary/test_utils
 
 let r = RepeatEosStruct.fromFile("src/repeat_eos_struct.bin")
 
-assert len(r.chunks) == int(2)
-assert r.chunks[0].offset == uint32(0)
-assert r.chunks[0].len == uint32(66)
-assert r.chunks[1].offset == uint32(66)
-assert r.chunks[1].len == uint32(2069)
+assert len(r.chunks) == 2
+assert r.chunks[0].offset == 0
+assert r.chunks[0].len == 66
+assert r.chunks[1].offset == 66
+assert r.chunks[1].len == 2069
diff --git a/spec/nim/trepeat_n_struct.nim b/spec/nim/trepeat_n_struct.nim
index 8546d204a..3a88b189e 100644
--- a/spec/nim/trepeat_n_struct.nim
+++ b/spec/nim/trepeat_n_struct.nim
@@ -6,8 +6,8 @@ import auxiliary/test_utils
 
 let r = RepeatNStruct.fromFile("src/repeat_n_struct.bin")
 
-assert len(r.chunks) == int(2)
-assert r.chunks[0].offset == uint32(16)
-assert r.chunks[0].len == uint32(8312)
-assert r.chunks[1].offset == uint32(8328)
-assert r.chunks[1].len == uint32(15)
+assert len(r.chunks) == 2
+assert r.chunks[0].offset == 16
+assert r.chunks[0].len == 8312
+assert r.chunks[1].offset == 8328
+assert r.chunks[1].len == 15
diff --git a/spec/nim/trepeat_n_strz.nim b/spec/nim/trepeat_n_strz.nim
index 3c98de0ac..17b805dfe 100644
--- a/spec/nim/trepeat_n_strz.nim
+++ b/spec/nim/trepeat_n_strz.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = RepeatNStrz.fromFile("src/repeat_n_strz.bin")
 
-assert r.qty == uint32(2)
+assert r.qty == 2
 assert r.lines == @[string("foo"), "bar"]
diff --git a/spec/nim/trepeat_n_strz_double.nim b/spec/nim/trepeat_n_strz_double.nim
index c9de502bd..bb1ca749d 100644
--- a/spec/nim/trepeat_n_strz_double.nim
+++ b/spec/nim/trepeat_n_strz_double.nim
@@ -6,6 +6,6 @@ import auxiliary/test_utils
 
 let r = RepeatNStrzDouble.fromFile("src/repeat_n_strz.bin")
 
-assert r.qty == uint32(2)
+assert r.qty == 2
 assert r.lines1 == @[string("foo"), ]
 assert r.lines2 == @[string("bar"), ]
diff --git a/spec/nim/trepeat_until_calc_array_type.nim b/spec/nim/trepeat_until_calc_array_type.nim
index 0fd9f4964..cfc564890 100644
--- a/spec/nim/trepeat_until_calc_array_type.nim
+++ b/spec/nim/trepeat_until_calc_array_type.nim
@@ -6,10 +6,10 @@ import auxiliary/test_utils
 
 let r = RepeatUntilCalcArrayType.fromFile("src/repeat_until_process.bin")
 
-assert len(r.records) == int(3)
-assert r.records[0].marker == uint8(232)
-assert r.records[0].body == uint32(2863311546'i64)
-assert r.records[1].marker == uint8(250)
-assert r.records[1].body == uint32(2863315102'i64)
-assert r.records[2].marker == uint8(170)
-assert r.records[2].body == uint32(1431655765)
+assert len(r.records) == 3
+assert r.records[0].marker == 232
+assert r.records[0].body == 2863311546'i64
+assert r.records[1].marker == 250
+assert r.records[1].body == 2863315102'i64
+assert r.records[2].marker == 170
+assert r.records[2].body == 1431655765
diff --git a/spec/nim/trepeat_until_complex.nim b/spec/nim/trepeat_until_complex.nim
index ef3f7fa70..e3db52e42 100644
--- a/spec/nim/trepeat_until_complex.nim
+++ b/spec/nim/trepeat_until_complex.nim
@@ -6,18 +6,18 @@ import auxiliary/test_utils
 
 let r = RepeatUntilComplex.fromFile("src/repeat_until_complex.bin")
 
-assert len(r.first) == int(3)
-assert r.first[0].count == uint8(4)
+assert len(r.first) == 3
+assert r.first[0].count == 4
 assert r.first[0].values == @[uint8((0 + 1)), 2, 3, 4]
-assert r.first[1].count == uint8(2)
+assert r.first[1].count == 2
 assert r.first[1].values == @[uint8((0 + 1)), 2]
-assert r.first[2].count == uint8(0)
-assert len(r.second) == int(4)
-assert r.second[0].count == uint16(6)
+assert r.first[2].count == 0
+assert len(r.second) == 4
+assert r.second[0].count == 6
 assert r.second[0].values == @[uint16((0 + 1)), 2, 3, 4, 5, 6]
-assert r.second[1].count == uint16(3)
+assert r.second[1].count == 3
 assert r.second[1].values == @[uint16((0 + 1)), 2, 3]
-assert r.second[2].count == uint16(4)
+assert r.second[2].count == 4
 assert r.second[2].values == @[uint16((0 + 1)), 2, 3, 4]
-assert r.second[3].count == uint16(0)
+assert r.second[3].count == 0
 assert r.third == @[uint8((0 + 102)), 111, 111, 98, 97, 114, 0]
diff --git a/spec/nim/trepeat_until_s4.nim b/spec/nim/trepeat_until_s4.nim
index d11bd4d1c..31afa57f6 100644
--- a/spec/nim/trepeat_until_s4.nim
+++ b/spec/nim/trepeat_until_s4.nim
@@ -7,4 +7,4 @@ import auxiliary/test_utils
 let r = RepeatUntilS4.fromFile("src/repeat_until_s4.bin")
 
 assert r.entries == @[int32(66), 4919, -251658241, -1]
-assert r.afterall == string("foobar")
+assert r.afterall == "foobar"
diff --git a/spec/nim/trepeat_until_sized.nim b/spec/nim/trepeat_until_sized.nim
index afe81dc7c..ff90478bd 100644
--- a/spec/nim/trepeat_until_sized.nim
+++ b/spec/nim/trepeat_until_sized.nim
@@ -6,10 +6,10 @@ import auxiliary/test_utils
 
 let r = RepeatUntilSized.fromFile("src/repeat_until_process.bin")
 
-assert len(r.records) == int(3)
-assert r.records[0].marker == uint8(232)
-assert r.records[0].body == uint32(2863311546'i64)
-assert r.records[1].marker == uint8(250)
-assert r.records[1].body == uint32(2863315102'i64)
-assert r.records[2].marker == uint8(170)
-assert r.records[2].body == uint32(1431655765)
+assert len(r.records) == 3
+assert r.records[0].marker == 232
+assert r.records[0].body == 2863311546'i64
+assert r.records[1].marker == 250
+assert r.records[1].body == 2863315102'i64
+assert r.records[2].marker == 170
+assert r.records[2].body == 1431655765
diff --git a/spec/nim/tstr_encodings.nim b/spec/nim/tstr_encodings.nim
index 3bf3bd253..1937a8969 100644
--- a/spec/nim/tstr_encodings.nim
+++ b/spec/nim/tstr_encodings.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = StrEncodings.fromFile("src/str_encodings.bin")
 
-assert r.str1 == string("Some ASCII")
-assert r.str2 == string("\u3053\u3093\u306b\u3061\u306f")
-assert r.str3 == string("\u3053\u3093\u306b\u3061\u306f")
-assert r.str4 == string("\u2591\u2592\u2593")
+assert r.str1 == "Some ASCII"
+assert r.str2 == "\u3053\u3093\u306b\u3061\u306f"
+assert r.str3 == "\u3053\u3093\u306b\u3061\u306f"
+assert r.str4 == "\u2591\u2592\u2593"
diff --git a/spec/nim/tstr_encodings_default.nim b/spec/nim/tstr_encodings_default.nim
index 2ee800661..99f66b87c 100644
--- a/spec/nim/tstr_encodings_default.nim
+++ b/spec/nim/tstr_encodings_default.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = StrEncodingsDefault.fromFile("src/str_encodings.bin")
 
-assert r.str1 == string("Some ASCII")
-assert r.rest.str2 == string("\u3053\u3093\u306b\u3061\u306f")
-assert r.rest.str3 == string("\u3053\u3093\u306b\u3061\u306f")
-assert r.rest.str4 == string("\u2591\u2592\u2593")
+assert r.str1 == "Some ASCII"
+assert r.rest.str2 == "\u3053\u3093\u306b\u3061\u306f"
+assert r.rest.str3 == "\u3053\u3093\u306b\u3061\u306f"
+assert r.rest.str4 == "\u2591\u2592\u2593"
diff --git a/spec/nim/tstr_eos.nim b/spec/nim/tstr_eos.nim
index 1ac84ec5b..a49a01edf 100644
--- a/spec/nim/tstr_eos.nim
+++ b/spec/nim/tstr_eos.nim
@@ -6,4 +6,4 @@ import auxiliary/test_utils
 
 let r = StrEos.fromFile("src/term_strz.bin")
 
-assert r.str == string("foo|bar|baz@")
+assert r.str == "foo|bar|baz@"
diff --git a/spec/nim/tstr_literals2.nim b/spec/nim/tstr_literals2.nim
index ff3c84539..6681db494 100644
--- a/spec/nim/tstr_literals2.nim
+++ b/spec/nim/tstr_literals2.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = StrLiterals2.fromFile("src/fixed_struct.bin")
 
-assert r.dollar1 == string("$foo")
-assert r.dollar2 == string("${foo}")
-assert r.hash == string("#{foo}")
-assert r.atSign == string("@foo")
+assert r.dollar1 == "$foo"
+assert r.dollar2 == "${foo}"
+assert r.hash == "#{foo}"
+assert r.atSign == "@foo"
diff --git a/spec/nim/tstr_pad_term.nim b/spec/nim/tstr_pad_term.nim
index bba98106c..f8144533a 100644
--- a/spec/nim/tstr_pad_term.nim
+++ b/spec/nim/tstr_pad_term.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = StrPadTerm.fromFile("src/str_pad_term.bin")
 
-assert r.strPad == string("str1")
-assert r.strTerm == string("str2foo")
-assert r.strTermAndPad == string("str+++3bar+++")
-assert r.strTermInclude == string("str4baz@")
+assert r.strPad == "str1"
+assert r.strTerm == "str2foo"
+assert r.strTermAndPad == "str+++3bar+++"
+assert r.strTermInclude == "str4baz@"
diff --git a/spec/nim/tstr_pad_term_empty.nim b/spec/nim/tstr_pad_term_empty.nim
index 474995ac8..dc82463de 100644
--- a/spec/nim/tstr_pad_term_empty.nim
+++ b/spec/nim/tstr_pad_term_empty.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = StrPadTermEmpty.fromFile("src/str_pad_term_empty.bin")
 
-assert r.strPad == string("")
-assert r.strTerm == string("")
-assert r.strTermAndPad == string("")
-assert r.strTermInclude == string("@")
+assert r.strPad == ""
+assert r.strTerm == ""
+assert r.strTermAndPad == ""
+assert r.strTermInclude == "@"
diff --git a/spec/nim/tswitch_bytearray.nim b/spec/nim/tswitch_bytearray.nim
index 79a6b1002..3d9ce9503 100644
--- a/spec/nim/tswitch_bytearray.nim
+++ b/spec/nim/tswitch_bytearray.nim
@@ -6,12 +6,12 @@ import auxiliary/test_utils
 
 let r = SwitchBytearray.fromFile("src/switch_opcodes.bin")
 
-assert len(r.opcodes) == int(4)
+assert len(r.opcodes) == 4
 assert r.opcodes[0].code == @[83'u8]
-assert (SwitchBytearray_Opcode_Strval(r.opcodes[0].body)).value == string("foobar")
+assert (SwitchBytearray_Opcode_Strval(r.opcodes[0].body)).value == "foobar"
 assert r.opcodes[1].code == @[73'u8]
-assert (SwitchBytearray_Opcode_Intval(r.opcodes[1].body)).value == uint8(66)
+assert (SwitchBytearray_Opcode_Intval(r.opcodes[1].body)).value == 66
 assert r.opcodes[2].code == @[73'u8]
-assert (SwitchBytearray_Opcode_Intval(r.opcodes[2].body)).value == uint8(55)
+assert (SwitchBytearray_Opcode_Intval(r.opcodes[2].body)).value == 55
 assert r.opcodes[3].code == @[83'u8]
-assert (SwitchBytearray_Opcode_Strval(r.opcodes[3].body)).value == string("")
+assert (SwitchBytearray_Opcode_Strval(r.opcodes[3].body)).value == ""
diff --git a/spec/nim/tswitch_else_only.nim b/spec/nim/tswitch_else_only.nim
index ee97e8569..f913fa073 100644
--- a/spec/nim/tswitch_else_only.nim
+++ b/spec/nim/tswitch_else_only.nim
@@ -6,6 +6,6 @@ import auxiliary/test_utils
 
 let r = SwitchElseOnly.fromFile("src/switch_opcodes.bin")
 
-assert r.opcode == int8(83)
-assert r.primByte == int8(102)
+assert r.opcode == 83
+assert r.primByte == 102
 assert r.ut.value == @[114'u8, 0'u8, 73'u8, 66'u8]
diff --git a/spec/nim/tswitch_integers.nim b/spec/nim/tswitch_integers.nim
index 17b37b877..aefd13fb6 100644
--- a/spec/nim/tswitch_integers.nim
+++ b/spec/nim/tswitch_integers.nim
@@ -6,12 +6,12 @@ import auxiliary/test_utils
 
 let r = SwitchIntegers.fromFile("src/switch_integers.bin")
 
-assert len(r.opcodes) == int(4)
-assert r.opcodes[0].code == uint8(1)
-assert r.opcodes[0].body == uint64(7)
-assert r.opcodes[1].code == uint8(2)
-assert r.opcodes[1].body == uint64(16448)
-assert r.opcodes[2].code == uint8(4)
-assert r.opcodes[2].body == uint64(4919)
-assert r.opcodes[3].code == uint8(8)
-assert r.opcodes[3].body == uint64(4919)
+assert len(r.opcodes) == 4
+assert r.opcodes[0].code == 1
+assert r.opcodes[0].body == 7
+assert r.opcodes[1].code == 2
+assert r.opcodes[1].body == 16448
+assert r.opcodes[2].code == 4
+assert r.opcodes[2].body == 4919
+assert r.opcodes[3].code == 8
+assert r.opcodes[3].body == 4919
diff --git a/spec/nim/tswitch_integers2.nim b/spec/nim/tswitch_integers2.nim
index 589fc1ac3..960482e4e 100644
--- a/spec/nim/tswitch_integers2.nim
+++ b/spec/nim/tswitch_integers2.nim
@@ -6,8 +6,8 @@ import auxiliary/test_utils
 
 let r = SwitchIntegers2.fromFile("src/switch_integers.bin")
 
-assert r.code == uint8(1)
-assert r.len == uint64(7)
+assert r.code == 1
+assert r.len == 7
 assert r.ham == @[2'u8, 64'u8, 64'u8, 4'u8, 55'u8, 19'u8, 0'u8]
-assert r.padding == uint8(0)
-assert r.lenModStr == string("13")
+assert r.padding == 0
+assert r.lenModStr == "13"
diff --git a/spec/nim/tswitch_manual_enum.nim b/spec/nim/tswitch_manual_enum.nim
index 30ba24d9d..e8e1c0c9b 100644
--- a/spec/nim/tswitch_manual_enum.nim
+++ b/spec/nim/tswitch_manual_enum.nim
@@ -6,12 +6,12 @@ import auxiliary/test_utils
 
 let r = SwitchManualEnum.fromFile("src/switch_opcodes.bin")
 
-assert len(r.opcodes) == int(4)
+assert len(r.opcodes) == 4
 assert r.opcodes[0].code == switch_manual_enum.strval
-assert (SwitchManualEnum_Opcode_Strval(r.opcodes[0].body)).value == string("foobar")
+assert (SwitchManualEnum_Opcode_Strval(r.opcodes[0].body)).value == "foobar"
 assert r.opcodes[1].code == switch_manual_enum.intval
-assert (SwitchManualEnum_Opcode_Intval(r.opcodes[1].body)).value == uint8(66)
+assert (SwitchManualEnum_Opcode_Intval(r.opcodes[1].body)).value == 66
 assert r.opcodes[2].code == switch_manual_enum.intval
-assert (SwitchManualEnum_Opcode_Intval(r.opcodes[2].body)).value == uint8(55)
+assert (SwitchManualEnum_Opcode_Intval(r.opcodes[2].body)).value == 55
 assert r.opcodes[3].code == switch_manual_enum.strval
-assert (SwitchManualEnum_Opcode_Strval(r.opcodes[3].body)).value == string("")
+assert (SwitchManualEnum_Opcode_Strval(r.opcodes[3].body)).value == ""
diff --git a/spec/nim/tswitch_manual_enum_invalid.nim b/spec/nim/tswitch_manual_enum_invalid.nim
index 197a3e3b8..54c96e519 100644
--- a/spec/nim/tswitch_manual_enum_invalid.nim
+++ b/spec/nim/tswitch_manual_enum_invalid.nim
@@ -6,8 +6,8 @@ import auxiliary/test_utils
 
 let r = SwitchManualEnumInvalid.fromFile("src/enum_negative.bin")
 
-assert len(r.opcodes) == int(2)
-assert r.opcodes[0].code == SwitchManualEnumInvalid_Opcode_CodeEnum(255)
+assert len(r.opcodes) == 2
+assert r.opcodes[0].code == 255
 assert r.opcodes[0].body == nil
-assert r.opcodes[1].code == SwitchManualEnumInvalid_Opcode_CodeEnum(1)
+assert r.opcodes[1].code == 1
 assert r.opcodes[1].body == nil
diff --git a/spec/nim/tswitch_manual_enum_invalid_else.nim b/spec/nim/tswitch_manual_enum_invalid_else.nim
index 0d3250047..7a2ea3aa0 100644
--- a/spec/nim/tswitch_manual_enum_invalid_else.nim
+++ b/spec/nim/tswitch_manual_enum_invalid_else.nim
@@ -6,8 +6,8 @@ import auxiliary/test_utils
 
 let r = SwitchManualEnumInvalidElse.fromFile("src/enum_negative.bin")
 
-assert len(r.opcodes) == int(2)
-assert r.opcodes[0].code == SwitchManualEnumInvalidElse_Opcode_CodeEnum(255)
-assert (SwitchManualEnumInvalidElse_Opcode_Defval(r.opcodes[0].body)).value == int8(123)
-assert r.opcodes[1].code == SwitchManualEnumInvalidElse_Opcode_CodeEnum(1)
-assert (SwitchManualEnumInvalidElse_Opcode_Defval(r.opcodes[1].body)).value == int8(123)
+assert len(r.opcodes) == 2
+assert r.opcodes[0].code == 255
+assert (SwitchManualEnumInvalidElse_Opcode_Defval(r.opcodes[0].body)).value == 123
+assert r.opcodes[1].code == 1
+assert (SwitchManualEnumInvalidElse_Opcode_Defval(r.opcodes[1].body)).value == 123
diff --git a/spec/nim/tswitch_manual_int.nim b/spec/nim/tswitch_manual_int.nim
index 9eb9cffff..996c64c77 100644
--- a/spec/nim/tswitch_manual_int.nim
+++ b/spec/nim/tswitch_manual_int.nim
@@ -6,12 +6,12 @@ import auxiliary/test_utils
 
 let r = SwitchManualInt.fromFile("src/switch_opcodes.bin")
 
-assert len(r.opcodes) == int(4)
-assert r.opcodes[0].code == uint8(83)
-assert (SwitchManualInt_Opcode_Strval(r.opcodes[0].body)).value == string("foobar")
-assert r.opcodes[1].code == uint8(73)
-assert (SwitchManualInt_Opcode_Intval(r.opcodes[1].body)).value == uint8(66)
-assert r.opcodes[2].code == uint8(73)
-assert (SwitchManualInt_Opcode_Intval(r.opcodes[2].body)).value == uint8(55)
-assert r.opcodes[3].code == uint8(83)
-assert (SwitchManualInt_Opcode_Strval(r.opcodes[3].body)).value == string("")
+assert len(r.opcodes) == 4
+assert r.opcodes[0].code == 83
+assert (SwitchManualInt_Opcode_Strval(r.opcodes[0].body)).value == "foobar"
+assert r.opcodes[1].code == 73
+assert (SwitchManualInt_Opcode_Intval(r.opcodes[1].body)).value == 66
+assert r.opcodes[2].code == 73
+assert (SwitchManualInt_Opcode_Intval(r.opcodes[2].body)).value == 55
+assert r.opcodes[3].code == 83
+assert (SwitchManualInt_Opcode_Strval(r.opcodes[3].body)).value == ""
diff --git a/spec/nim/tswitch_manual_int_else.nim b/spec/nim/tswitch_manual_int_else.nim
index 2c615d01c..648ce27b5 100644
--- a/spec/nim/tswitch_manual_int_else.nim
+++ b/spec/nim/tswitch_manual_int_else.nim
@@ -6,12 +6,12 @@ import auxiliary/test_utils
 
 let r = SwitchManualIntElse.fromFile("src/switch_opcodes2.bin")
 
-assert len(r.opcodes) == int(4)
-assert r.opcodes[0].code == uint8(83)
-assert (SwitchManualIntElse_Opcode_Strval(r.opcodes[0].body)).value == string("foo")
-assert r.opcodes[1].code == uint8(88)
-assert (SwitchManualIntElse_Opcode_Noneval(r.opcodes[1].body)).filler == uint32(66)
-assert r.opcodes[2].code == uint8(89)
-assert (SwitchManualIntElse_Opcode_Noneval(r.opcodes[2].body)).filler == uint32(51966)
-assert r.opcodes[3].code == uint8(73)
-assert (SwitchManualIntElse_Opcode_Intval(r.opcodes[3].body)).value == uint8(7)
+assert len(r.opcodes) == 4
+assert r.opcodes[0].code == 83
+assert (SwitchManualIntElse_Opcode_Strval(r.opcodes[0].body)).value == "foo"
+assert r.opcodes[1].code == 88
+assert (SwitchManualIntElse_Opcode_Noneval(r.opcodes[1].body)).filler == 66
+assert r.opcodes[2].code == 89
+assert (SwitchManualIntElse_Opcode_Noneval(r.opcodes[2].body)).filler == 51966
+assert r.opcodes[3].code == 73
+assert (SwitchManualIntElse_Opcode_Intval(r.opcodes[3].body)).value == 7
diff --git a/spec/nim/tswitch_manual_int_size.nim b/spec/nim/tswitch_manual_int_size.nim
index f10a41de2..e49d6fd4f 100644
--- a/spec/nim/tswitch_manual_int_size.nim
+++ b/spec/nim/tswitch_manual_int_size.nim
@@ -6,13 +6,13 @@ import auxiliary/test_utils
 
 let r = SwitchManualIntSize.fromFile("src/switch_tlv.bin")
 
-assert len(r.chunks) == int(4)
-assert r.chunks[0].code == uint8(17)
-assert (SwitchManualIntSize_Chunk_ChunkMeta(r.chunks[0].body)).title == string("Stuff")
-assert (SwitchManualIntSize_Chunk_ChunkMeta(r.chunks[0].body)).author == string("Me")
-assert r.chunks[1].code == uint8(34)
+assert len(r.chunks) == 4
+assert r.chunks[0].code == 17
+assert (SwitchManualIntSize_Chunk_ChunkMeta(r.chunks[0].body)).title == "Stuff"
+assert (SwitchManualIntSize_Chunk_ChunkMeta(r.chunks[0].body)).author == "Me"
+assert r.chunks[1].code == 34
 assert (SwitchManualIntSize_Chunk_ChunkDir(r.chunks[1].body)).entries == @[string("AAAA"), "BBBB", "CCCC"]
-assert r.chunks[2].code == uint8(51)
+assert r.chunks[2].code == 51
 assert (seq[byte](r.chunks[2].body)) == @[16'u8, 32'u8, 48'u8, 64'u8, 80'u8, 96'u8, 112'u8, 128'u8]
-assert r.chunks[3].code == uint8(255)
+assert r.chunks[3].code == 255
 assert (seq[byte](r.chunks[3].body)) == @[]
diff --git a/spec/nim/tswitch_manual_int_size_else.nim b/spec/nim/tswitch_manual_int_size_else.nim
index 6a1d26bd3..aa74f00f3 100644
--- a/spec/nim/tswitch_manual_int_size_else.nim
+++ b/spec/nim/tswitch_manual_int_size_else.nim
@@ -6,13 +6,13 @@ import auxiliary/test_utils
 
 let r = SwitchManualIntSizeElse.fromFile("src/switch_tlv.bin")
 
-assert len(r.chunks) == int(4)
-assert r.chunks[0].code == uint8(17)
-assert (SwitchManualIntSizeElse_Chunk_ChunkMeta(r.chunks[0].body)).title == string("Stuff")
-assert (SwitchManualIntSizeElse_Chunk_ChunkMeta(r.chunks[0].body)).author == string("Me")
-assert r.chunks[1].code == uint8(34)
+assert len(r.chunks) == 4
+assert r.chunks[0].code == 17
+assert (SwitchManualIntSizeElse_Chunk_ChunkMeta(r.chunks[0].body)).title == "Stuff"
+assert (SwitchManualIntSizeElse_Chunk_ChunkMeta(r.chunks[0].body)).author == "Me"
+assert r.chunks[1].code == 34
 assert (SwitchManualIntSizeElse_Chunk_ChunkDir(r.chunks[1].body)).entries == @[string("AAAA"), "BBBB", "CCCC"]
-assert r.chunks[2].code == uint8(51)
+assert r.chunks[2].code == 51
 assert (SwitchManualIntSizeElse_Chunk_Dummy(r.chunks[2].body)).rest == @[16'u8, 32'u8, 48'u8, 64'u8, 80'u8, 96'u8, 112'u8, 128'u8]
-assert r.chunks[3].code == uint8(255)
+assert r.chunks[3].code == 255
 assert (SwitchManualIntSizeElse_Chunk_Dummy(r.chunks[3].body)).rest == @[]
diff --git a/spec/nim/tswitch_manual_str.nim b/spec/nim/tswitch_manual_str.nim
index 84cf3f652..78a678fcb 100644
--- a/spec/nim/tswitch_manual_str.nim
+++ b/spec/nim/tswitch_manual_str.nim
@@ -6,12 +6,12 @@ import auxiliary/test_utils
 
 let r = SwitchManualStr.fromFile("src/switch_opcodes.bin")
 
-assert len(r.opcodes) == int(4)
-assert r.opcodes[0].code == string("S")
-assert (SwitchManualStr_Opcode_Strval(r.opcodes[0].body)).value == string("foobar")
-assert r.opcodes[1].code == string("I")
-assert (SwitchManualStr_Opcode_Intval(r.opcodes[1].body)).value == uint8(66)
-assert r.opcodes[2].code == string("I")
-assert (SwitchManualStr_Opcode_Intval(r.opcodes[2].body)).value == uint8(55)
-assert r.opcodes[3].code == string("S")
-assert (SwitchManualStr_Opcode_Strval(r.opcodes[3].body)).value == string("")
+assert len(r.opcodes) == 4
+assert r.opcodes[0].code == "S"
+assert (SwitchManualStr_Opcode_Strval(r.opcodes[0].body)).value == "foobar"
+assert r.opcodes[1].code == "I"
+assert (SwitchManualStr_Opcode_Intval(r.opcodes[1].body)).value == 66
+assert r.opcodes[2].code == "I"
+assert (SwitchManualStr_Opcode_Intval(r.opcodes[2].body)).value == 55
+assert r.opcodes[3].code == "S"
+assert (SwitchManualStr_Opcode_Strval(r.opcodes[3].body)).value == ""
diff --git a/spec/nim/tswitch_manual_str_else.nim b/spec/nim/tswitch_manual_str_else.nim
index 065dd99d4..65819a293 100644
--- a/spec/nim/tswitch_manual_str_else.nim
+++ b/spec/nim/tswitch_manual_str_else.nim
@@ -6,12 +6,12 @@ import auxiliary/test_utils
 
 let r = SwitchManualStrElse.fromFile("src/switch_opcodes2.bin")
 
-assert len(r.opcodes) == int(4)
-assert r.opcodes[0].code == string("S")
-assert (SwitchManualStrElse_Opcode_Strval(r.opcodes[0].body)).value == string("foo")
-assert r.opcodes[1].code == string("X")
-assert (SwitchManualStrElse_Opcode_Noneval(r.opcodes[1].body)).filler == uint32(66)
-assert r.opcodes[2].code == string("Y")
-assert (SwitchManualStrElse_Opcode_Noneval(r.opcodes[2].body)).filler == uint32(51966)
-assert r.opcodes[3].code == string("I")
-assert (SwitchManualStrElse_Opcode_Intval(r.opcodes[3].body)).value == uint8(7)
+assert len(r.opcodes) == 4
+assert r.opcodes[0].code == "S"
+assert (SwitchManualStrElse_Opcode_Strval(r.opcodes[0].body)).value == "foo"
+assert r.opcodes[1].code == "X"
+assert (SwitchManualStrElse_Opcode_Noneval(r.opcodes[1].body)).filler == 66
+assert r.opcodes[2].code == "Y"
+assert (SwitchManualStrElse_Opcode_Noneval(r.opcodes[2].body)).filler == 51966
+assert r.opcodes[3].code == "I"
+assert (SwitchManualStrElse_Opcode_Intval(r.opcodes[3].body)).value == 7
diff --git a/spec/nim/tswitch_repeat_expr.nim b/spec/nim/tswitch_repeat_expr.nim
index ae95e2bfa..a2afce098 100644
--- a/spec/nim/tswitch_repeat_expr.nim
+++ b/spec/nim/tswitch_repeat_expr.nim
@@ -6,6 +6,6 @@ import auxiliary/test_utils
 
 let r = SwitchRepeatExpr.fromFile("src/switch_tlv.bin")
 
-assert r.code == uint8(17)
-assert r.size == uint32(9)
+assert r.code == 17
+assert r.size == 9
 assert (SwitchRepeatExpr_One(r.body[0])).first == @[83'u8, 116'u8, 117'u8, 102'u8, 102'u8, 0'u8, 77'u8, 101'u8, 0'u8]
diff --git a/spec/nim/tswitch_repeat_expr_invalid.nim b/spec/nim/tswitch_repeat_expr_invalid.nim
index bb8cc1000..442bf2d8b 100644
--- a/spec/nim/tswitch_repeat_expr_invalid.nim
+++ b/spec/nim/tswitch_repeat_expr_invalid.nim
@@ -6,6 +6,6 @@ import auxiliary/test_utils
 
 let r = SwitchRepeatExprInvalid.fromFile("src/switch_tlv.bin")
 
-assert r.code == uint8(17)
-assert r.size == uint32(9)
+assert r.code == 17
+assert r.size == 9
 assert (seq[byte](r.body[0])) == @[83'u8, 116'u8, 117'u8, 102'u8, 102'u8, 0'u8, 77'u8, 101'u8, 0'u8]
diff --git a/spec/nim/tterm_strz.nim b/spec/nim/tterm_strz.nim
index 1dc96bc23..6bdc6de0d 100644
--- a/spec/nim/tterm_strz.nim
+++ b/spec/nim/tterm_strz.nim
@@ -6,6 +6,6 @@ import auxiliary/test_utils
 
 let r = TermStrz.fromFile("src/term_strz.bin")
 
-assert r.s1 == string("foo")
-assert r.s2 == string("bar")
-assert r.s3 == string("|baz@")
+assert r.s1 == "foo"
+assert r.s2 == "bar"
+assert r.s3 == "|baz@"
diff --git a/spec/nim/tterm_u1_val.nim b/spec/nim/tterm_u1_val.nim
index ba707f4d9..1d187e286 100644
--- a/spec/nim/tterm_u1_val.nim
+++ b/spec/nim/tterm_u1_val.nim
@@ -7,4 +7,4 @@ import auxiliary/test_utils
 let r = TermU1Val.fromFile("src/str_encodings.bin")
 
 assert r.foo == @[10'u8, 0'u8, 83'u8, 111'u8, 109'u8, 101'u8, 32'u8, 65'u8, 83'u8, 67'u8, 73'u8, 73'u8, 15'u8, 0'u8]
-assert r.bar == string("\u3053\u3093\u306b")
+assert r.bar == "\u3053\u3093\u306b"
diff --git a/spec/nim/tts_packet_header.nim b/spec/nim/tts_packet_header.nim
index 513b28ea5..96e3d4bfb 100644
--- a/spec/nim/tts_packet_header.nim
+++ b/spec/nim/tts_packet_header.nim
@@ -6,10 +6,10 @@ import auxiliary/test_utils
 
 let r = TsPacketHeader.fromFile("src/ts_packet.bin")
 
-assert r.syncByte == uint8(71)
-assert r.transportErrorIndicator == bool(false)
-assert r.payloadUnitStartIndicator == bool(false)
-assert r.transportPriority == bool(true)
-assert r.pid == uint64(33)
-assert r.transportScramblingControl == uint64(0)
+assert r.syncByte == 71
+assert r.transportErrorIndicator == false
+assert r.payloadUnitStartIndicator == false
+assert r.transportPriority == true
+assert r.pid == 33
+assert r.transportScramblingControl == 0
 assert r.adaptationFieldControl == ts_packet_header.payload_only
diff --git a/spec/nim/ttype_int_unary_op.nim b/spec/nim/ttype_int_unary_op.nim
index e53eb585e..1e1b2c603 100644
--- a/spec/nim/ttype_int_unary_op.nim
+++ b/spec/nim/ttype_int_unary_op.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = TypeIntUnaryOp.fromFile("src/fixed_struct.bin")
 
-assert r.valueS2 == int16(16720)
-assert r.valueS8 == int64(4706543082108963651'i64)
-assert r.unaryS2 == int(-16720)
-assert r.unaryS8 == int64(-4706543082108963651'i64)
+assert r.valueS2 == 16720
+assert r.valueS8 == 4706543082108963651'i64
+assert r.unaryS2 == -16720
+assert r.unaryS8 == -4706543082108963651'i64
diff --git a/spec/nim/ttype_ternary.nim b/spec/nim/ttype_ternary.nim
index b306d021d..44744ded2 100644
--- a/spec/nim/ttype_ternary.nim
+++ b/spec/nim/ttype_ternary.nim
@@ -6,4 +6,4 @@ import auxiliary/test_utils
 
 let r = TypeTernary.fromFile("src/term_strz.bin")
 
-assert r.dif.value == uint8(101)
+assert r.dif.value == 101
diff --git a/spec/nim/ttype_ternary_2nd_falsy.nim b/spec/nim/ttype_ternary_2nd_falsy.nim
index 44cfbe187..c2b4ca524 100644
--- a/spec/nim/ttype_ternary_2nd_falsy.nim
+++ b/spec/nim/ttype_ternary_2nd_falsy.nim
@@ -6,16 +6,16 @@ import auxiliary/test_utils
 
 let r = TypeTernary2ndFalsy.fromFile("src/switch_integers.bin")
 
-assert r.vFalse == bool(false)
-assert r.vIntZero == int8(0)
-assert r.vIntNegZero == int(-0)
-assert r.vFloatZero == float64(0.0)
-assert r.vFloatNegZero == float64(-0.0)
-assert r.vStrWZero == string("0")
-assert len(r.vStrWZero) == int(1)
-assert r.ut.m == uint8(7)
+assert r.vFalse == false
+assert r.vIntZero == 0
+assert r.vIntNegZero == -0
+assert r.vFloatZero == 0.0
+assert r.vFloatNegZero == -0.0
+assert r.vStrWZero == "0"
+assert len(r.vStrWZero) == 1
+assert r.ut.m == 7
 assert r.vNullUt == nil
-assert r.vStrEmpty == string("")
-assert len(r.vStrEmpty) == int(0)
-assert len(r.intArray) == int(2)
-assert len(r.vIntArrayEmpty) == int(0)
+assert r.vStrEmpty == ""
+assert len(r.vStrEmpty) == 0
+assert len(r.intArray) == 2
+assert len(r.vIntArrayEmpty) == 0
diff --git a/spec/nim/tuser_type.nim b/spec/nim/tuser_type.nim
index 60cfd2edc..a53352d01 100644
--- a/spec/nim/tuser_type.nim
+++ b/spec/nim/tuser_type.nim
@@ -6,5 +6,5 @@ import auxiliary/test_utils
 
 let r = UserType.fromFile("src/repeat_until_s4.bin")
 
-assert r.one.width == uint32(66)
-assert r.one.height == uint32(4919)
+assert r.one.width == 66
+assert r.one.height == 4919
diff --git a/spec/nim/tyaml_ints.nim b/spec/nim/tyaml_ints.nim
index 57b3c4c0b..999f077bf 100644
--- a/spec/nim/tyaml_ints.nim
+++ b/spec/nim/tyaml_ints.nim
@@ -6,7 +6,7 @@ import auxiliary/test_utils
 
 let r = YamlInts.fromFile("src/fixed_struct.bin")
 
-assert r.testU4Dec == int(4294967295'i64)
-assert r.testU4Hex == int(4294967295'i64)
-assert r.testU8Dec == int(18446744073709551615'u64)
-assert r.testU8Hex == int(18446744073709551615'u64)
+assert r.testU4Dec == 4294967295'i64
+assert r.testU4Hex == 4294967295'i64
+assert r.testU8Dec == 18446744073709551615'u64
+assert r.testU8Hex == 18446744073709551615'u64
diff --git a/spec/nim/tzlib_surrounded.nim b/spec/nim/tzlib_surrounded.nim
index 167c9445b..460d468b4 100644
--- a/spec/nim/tzlib_surrounded.nim
+++ b/spec/nim/tzlib_surrounded.nim
@@ -6,4 +6,4 @@ import auxiliary/test_utils
 
 let r = ZlibSurrounded.fromFile("src/zlib_surrounded.bin")
 
-assert r.zlib.num == int32(-1)
+assert r.zlib.num == -1
diff --git a/translator/src/main/scala/io/kaitai/struct/testtranslator/specgenerators/NimSG.scala b/translator/src/main/scala/io/kaitai/struct/testtranslator/specgenerators/NimSG.scala
index dead8c60f..5f3b25a34 100644
--- a/translator/src/main/scala/io/kaitai/struct/testtranslator/specgenerators/NimSG.scala
+++ b/translator/src/main/scala/io/kaitai/struct/testtranslator/specgenerators/NimSG.scala
@@ -61,12 +61,7 @@ class NimSG(spec: TestSpec, provider: ClassTypeProvider) extends BaseGenerator(s
   override def simpleAssert(check: TestAssert): Unit = {
     val actStr = translateAct(check.actual)
     val expStr = translator.translate(check.expected)
-    val td = new TypeDetector(provider)
-    val ta = ksToNim(td.detectType(check.actual))
-    td.detectType(check.expected) match {
-      case _: EnumType | _: BytesType | _: ArrayType => out.puts(s"assert $actStr == $expStr")
-      case _ => out.puts(s"assert $actStr == $ta($expStr)")
-    }
+    out.puts(s"assert $actStr == $expStr")
   }
   override def trueArrayAssert(check: TestAssert, elType: DataType, elts: Seq[expr]): Unit = {
     val arr = elts.map(v => translator.translate(v))