Add Set val instruction.

README.md

@@ -9,6 +9,8 @@ Uses signed 16bit ints for data, memory wraps around at 65535, EOF returns -1.
 
 repeat ++++ or --- are replaced with a single addition/subtraction
 
+addition/subtraction after zero does a blind set.
+
 repeat >>> or <<< are replaced with a single pointer jump
 
 [>>+<<-] and [->>+<<] merged into a move instruction.

parser/execute.go

@@ -19,6 +19,8 @@ func Execute(program []Instruction, reader io.ByteReader, writer *bufio.Writer)
 			dataPtr = dataPtr & 0xFFFF
 		case opAddVal:
 			data[dataPtr] += int16(program[pc].operand)
+		case opSetVal:
+			data[dataPtr] = int16(program[pc].operand)
 		case opOut:
 			writer.WriteByte(byte(data[dataPtr] & 0xff))
 			writeCount++

parser/instruction.go

@@ -17,6 +17,7 @@ const (
 	opNoop Opcode = iota
 	opAddDp
 	opAddVal
+	opSetVal
 	opOut
 	opIn
 	opJmpZ
@@ -31,6 +32,7 @@ func (inst Instruction) String() string {
 		"nop",
 		"ptr",
 		"add",
+		"set",
 		"out",
 		"in",
 		"jmpz",

parser/tokenise.go

@@ -34,6 +34,15 @@ func Tokenise(input io.ByteReader) (program []Instruction, err error) {
 				program[pc-1].operand += program[pc].operand
 				program = program[:pc]
 				pc--
+			} else if program[pc-1].operator == opSetVal {
+				program[pc-1].operand += program[pc].operand
+				program = program[:pc]
+				pc--
+			} else if program[pc-1].operator == opJmpNz ||
+				program[pc-1].operator == opZero {
+				operand := program[pc].operand
+				program = program[:pc]
+				program = append(program, Instruction{opSetVal, operand})
 			}
 		case opJmpZ:
 			jmpStack = append(jmpStack, pc)

parser/tokenise_test.go

@@ -16,11 +16,13 @@ func TestTokenise(t *testing.T) {
 	}{
 		{
 			"small_prog",
-			">>>>>[-]zero+++++[->>+<<]move>>",
+			">>>>>[-]zero+++++>+++++[->>+<<]move>>",
 			[]Instruction{
 				Instruction{opNoop, 0},
 				Instruction{opAddDp, 5},
 				Instruction{opZero, 0},
+				Instruction{opSetVal, 5},
+				Instruction{opAddDp, 1},
 				Instruction{opAddVal, 5},
 				Instruction{opMove, 2},
 				Instruction{opAddDp, 2},

sample/minify.bf

@@ -0,0 +1,59 @@
+#!/usr/bin/env bf
+[SPDX-FileCopyrightText: Brainfuck Enterprise Solutions
+ SPDX-License-Identifier: WTFPL]
+[format.bf---Brainfuck code minifier.
+
+ Removes all the non-command character from the input. The input
+ should be valid Brainfuck code with balanced square brackets,
+ followed by the exclamation sign. The output is minified code as one
+ line without non-command characters
+
+ Memory layout is:
+ [case flag][char][char copy]
+
+ Code starts here:]
+read char until EOF (-1)
+,+
+[ restore the char
+ -
+ [>+>+<<-] duplicate the char
+ +> set case flag
+ [ plus (43)
+  ----- ----- ----- -----
+  ----- ----- ----- ----- ---
+  [ comma (44)
+   -
+   [ minus (45)
+    -
+    [ period (46)
+     -
+     [ less than (60)
+      ----- ----- ----
+      [ more than (62)
+       --
+       [ opening bracket (91)
+        ----- ----- ----- ----- ----- ----
+        [ closing bracket (93)
+         --
+         default: kill the char and case flag and copy
+         [<->[-]>[-]<]
+         command case: kill flag
+         <[-]>]
+        command case: kill flag
+        <[-]>]
+       command case: kill flag
+       <[-]>]
+      command case: kill flag
+      <[-]>]
+     command case: kill flag
+     <[-]>]
+    command case: kill flag
+    <[-]>]
+   command case: kill flag
+   <[-]>]
+  command case: kill flag
+  <[-]>]
+ >[.[-]] print and kill the copy
+ read a new char and subtract exclamation mark
+ <<,+]
+++++++++++.