Declaration based compilation units.

README.md

@@ -6,16 +6,18 @@ Very WIP. Like VERY.
 
 ```pork
 /* fibonacci sequence */
-fib = { n in
+fn fib(n) {
   if n == 0
     then 0
   else if n == 1
     then 1
   else fib(n - 1) + fib(n - 2)
 }
 
-result = fib(20)
-println(result)
+fn main() {
+  result = fib(20)
+  println(result)
+}
 ```
 
 ## Usage

examples/fib.pork

@@ -1,11 +1,13 @@
 /* fibonacci sequence */
-fib = { n in
+fn fib(n) {
   if n == 0
     then 0
   else if n == 1
     then 1
   else fib(n - 1) + fib(n - 2)
 }
 
-result = fib(20)
-println(result)
+fn main() {
+  result = fib(20)
+  println(result)
+}

examples/syntax.pork

@@ -1,53 +1,55 @@
-three = 3
-two = 2
-
-calculateSimple = { in
-  (50 + three) * two
-}
-
-calculateComplex = { in
-  three + two + 50
-}
-
-multiply = { a, b in
-  a * b
-}
-
-// calculates the result
-calculateSimpleResult = calculateSimple()
-calculateComplexResult = calculateComplex()
-multiplyResult = multiply(50, 50)
-
-list = [10, 20, 30]
-trueValue = true
-falseValue = false
-
-invert = { value in
-  !value
-}
-
-notEqual = { a, b in
-  a != b
+fn main() {
+  three = 3
+  two = 2
+
+  calculateSimple = { in
+    (50 + three) * two
+  }
+
+  calculateComplex = { in
+    three + two + 50
+  }
+
+  multiply = { a, b in
+    a * b
+  }
+
+  // calculates the result
+  calculateSimpleResult = calculateSimple()
+  calculateComplexResult = calculateComplex()
+  multiplyResult = multiply(50, 50)
+
+  list = [10, 20, 30]
+  trueValue = true
+  falseValue = false
+
+  invert = { value in
+    !value
+  }
+
+  notEqual = { a, b in
+    a != b
+  }
+
+  equal = { a, b in
+    a == b
+  }
+
+  results = [
+    calculateSimpleResult,
+    calculateComplexResult,
+    multiplyResult,
+    list,
+    trueValue,
+    falseValue,
+    invert(true),
+    invert(false),
+    equal(5, 5),
+    equal(5, 6),
+    notEqual(5, 5),
+    notEqual(5, 6)
+  ]
+
+  println("results:")
+  println(results)
 }
-
-equal = { a, b in
-  a == b
-}
-
-results = [
-  calculateSimpleResult,
-  calculateComplexResult,
-  multiplyResult,
-  list,
-  trueValue,
-  falseValue,
-  invert(true),
-  invert(false),
-  equal(5, 5),
-  equal(5, 6),
-  notEqual(5, 5),
-  notEqual(5, 6)
-]
-
-println("results:")
-println(results)

src/main/kotlin/gay/pizza/pork/ast/NodeCoalescer.kt

@@ -16,7 +16,10 @@ class NodeCoalescer(val handler: (Node) -> Unit) : NodeVisitor<Unit> {
   override fun visitPrefixOperation(node: PrefixOperation): Unit = handle(node)
   override fun visitIf(node: If): Unit = handle(node)
   override fun visitInfixOperation(node: InfixOperation): Unit = handle(node)
-  override fun visitProgram(node: Program): Unit = handle(node)
+  override fun visitFunctionDeclaration(node: FunctionDeclaration): Unit = handle(node)
+  override fun visitBlock(node: Block): Unit = handle(node)
+
+  override fun visitCompilationUnit(node: CompilationUnit): Unit = handle(node)
 
   private fun handle(node: Node) {
     handler(node)

src/main/kotlin/gay/pizza/pork/ast/NodeType.kt

@@ -4,7 +4,9 @@ enum class NodeType(val parent: NodeType? = null) {
   Node,
   Symbol(Node),
   Expression(Node),
-  Program(Node),
+  Declaration(Node),
+  Block(Node),
+  CompilationUnit(Node),
   IntLiteral(Expression),
   BooleanLiteral(Expression),
   ListLiteral(Expression),
@@ -16,7 +18,8 @@ enum class NodeType(val parent: NodeType? = null) {
   InfixOperation(Expression),
   SymbolReference(Expression),
   FunctionCall(Expression),
-  If(Expression);
+  If(Expression),
+  FunctionDeclaration(Declaration);
 
   val parents: Set<NodeType>
 

src/main/kotlin/gay/pizza/pork/ast/NodeVisitor.kt

@@ -16,7 +16,10 @@ interface NodeVisitor<T> {
   fun visitPrefixOperation(node: PrefixOperation): T
   fun visitIf(node: If): T
   fun visitInfixOperation(node: InfixOperation): T
-  fun visitProgram(node: Program): T
+  fun visitFunctionDeclaration(node: FunctionDeclaration): T
+  fun visitBlock(node: Block): T
+
+  fun visitCompilationUnit(node: CompilationUnit): T
 
   fun visitExpression(node: Expression): T = when (node) {
     is IntLiteral -> visitIntLiteral(node)
@@ -33,10 +36,16 @@ interface NodeVisitor<T> {
     is InfixOperation -> visitInfixOperation(node)
   }
 
+  fun visitDeclaration(node: Declaration): T = when (node) {
+    is FunctionDeclaration -> visitFunctionDeclaration(node)
+  }
+
   fun visit(node: Node): T = when (node) {
     is Symbol -> visitSymbol(node)
     is Expression -> visitExpression(node)
-    is Program -> visitProgram(node)
+    is CompilationUnit -> visitCompilationUnit(node)
+    is Block -> visitBlock(node)
+    is Declaration -> visitDeclaration(node)
   }
 
   fun visitNodes(vararg nodes: Node?): List<T> =

src/main/kotlin/gay/pizza/pork/ast/Printer.kt

@@ -82,7 +82,6 @@ class Printer(buffer: StringBuilder) : NodeVisitor<Unit> {
     visit(node.symbol)
   }
 
-
   override fun visitLambda(node: Lambda) {
     append("{")
     if (node.arguments.isNotEmpty()) {
@@ -148,10 +147,37 @@ class Printer(buffer: StringBuilder) : NodeVisitor<Unit> {
     visit(node.right)
   }
 
-  override fun visitProgram(node: Program) {
-    for (expression in node.expressions) {
-      out.emitIndent()
-      visit(expression)
+  override fun visitFunctionDeclaration(node: FunctionDeclaration) {
+    append("fn ")
+    visit(node.symbol)
+    append("(")
+    for ((index, argument) in node.arguments.withIndex()) {
+      visit(argument)
+      if (index + 1 != node.arguments.size) {
+        append(", ")
+      }
+    }
+    append(") ")
+    visit(node.block)
+  }
+
+  override fun visitBlock(node: Block) {
+    append("{")
+    if (node.expressions.isNotEmpty()) {
+      out.increaseIndent()
+      for (expression in node.expressions) {
+        appendLine()
+        visit(expression)
+      }
+      out.decreaseIndent()
+      appendLine()
+    }
+    append("}")
+  }
+
+  override fun visitCompilationUnit(node: CompilationUnit) {
+    for (declaration in node.declarations) {
+      visit(declaration)
       appendLine()
     }
   }

src/main/kotlin/gay/pizza/pork/ast/nodes/Program.kt → src/main/kotlin/gay/pizza/pork/ast/nodes/Block.kt

@@ -6,15 +6,15 @@ import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
 
 @Serializable
-@SerialName("program")
-class Program(val expressions: List<Expression>) : Node() {
-  override val type: NodeType = NodeType.Program
+@SerialName("block")
+class Block(val expressions: List<Expression>) : Node() {
+  override val type: NodeType = NodeType.Block
 
   override fun <T> visitChildren(visitor: NodeVisitor<T>): List<T> =
     visitor.visitAll(expressions)
 
   override fun equals(other: Any?): Boolean {
-    if (other !is Program) return false
+    if (other !is Block) return false
     return other.expressions == expressions
   }
 

src/main/kotlin/gay/pizza/pork/ast/nodes/CompilationUnit.kt

@@ -0,0 +1,26 @@
+package gay.pizza.pork.ast.nodes
+
+import gay.pizza.pork.ast.NodeType
+import gay.pizza.pork.ast.NodeVisitor
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+@SerialName("compilationUnit")
+class CompilationUnit(val declarations: List<Declaration>) : Node() {
+  override val type: NodeType = NodeType.CompilationUnit
+
+  override fun <T> visitChildren(visitor: NodeVisitor<T>): List<T> =
+    visitor.visitAll(declarations)
+
+  override fun equals(other: Any?): Boolean {
+    if (other !is CompilationUnit) return false
+    return other.declarations == declarations
+  }
+
+  override fun hashCode(): Int {
+    var result = declarations.hashCode()
+    result = 31 * result + type.hashCode()
+    return result
+  }
+}

src/main/kotlin/gay/pizza/pork/ast/nodes/Declaration.kt

@@ -0,0 +1,6 @@
+package gay.pizza.pork.ast.nodes
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+sealed class Declaration : Node()

src/main/kotlin/gay/pizza/pork/ast/nodes/FunctionDeclaration.kt

@@ -0,0 +1,28 @@
+package gay.pizza.pork.ast.nodes
+
+import gay.pizza.pork.ast.NodeType
+import gay.pizza.pork.ast.NodeVisitor
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+@SerialName("functionDeclaration")
+class FunctionDeclaration(val symbol: Symbol, val arguments: List<Symbol>, val block: Block) : Declaration() {
+  override val type: NodeType = NodeType.FunctionDeclaration
+
+  override fun <T> visitChildren(visitor: NodeVisitor<T>): List<T> =
+    visitor.visitNodes(symbol)
+
+  override fun equals(other: Any?): Boolean {
+    if (other !is FunctionDeclaration) return false
+    return other.symbol == symbol && other.arguments == arguments && other.block == block
+  }
+
+  override fun hashCode(): Int {
+    var result = symbol.hashCode()
+    result = 31 * result + symbol.hashCode()
+    result = 31 * result + arguments.hashCode()
+    result = 31 * result + block.hashCode()
+    return result
+  }
+}

src/main/kotlin/gay/pizza/pork/cli/AttributeCommand.kt

@@ -13,7 +13,7 @@ class AttributeCommand : CliktCommand(help = "Attribute AST", name = "attribute"
   override fun run() {
     val frontend = FileFrontend(path)
     val attribution = TokenNodeAttribution()
-    val program = frontend.parse(attribution)
+    val compilationUnit = frontend.parse(attribution)
 
     val coalescer = NodeCoalescer { node ->
       val tokens = attribution.assembleTokens(node)
@@ -22,6 +22,6 @@ class AttributeCommand : CliktCommand(help = "Attribute AST", name = "attribute"
         println("token $token")
       }
     }
-    coalescer.visit(program)
+    coalescer.visit(compilationUnit)
   }
 }