language: today, we killed lambdas

ast/src/main/ast/pork.yml

@@ -115,13 +115,6 @@ types:
     values:
     - name: value
       type: Int
-  Lambda:
-    parent: Expression
-    values:
-    - name: arguments
-      type: List<Symbol>
-    - name: expressions
-      type: List<Expression>
   ListLiteral:
     parent: Expression
     values:

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

@@ -1,29 +0,0 @@
-// GENERATED CODE FROM PORK AST CODEGEN
-package gay.pizza.pork.ast
-
-import kotlinx.serialization.SerialName
-import kotlinx.serialization.Serializable
-
-@Serializable
-@SerialName("lambda")
-class Lambda(val arguments: List<Symbol>, val expressions: List<Expression>) : Expression() {
-  override val type: NodeType = NodeType.Lambda
-
-  override fun <T> visitChildren(visitor: NodeVisitor<T>): List<T> =
-    visitor.visitAll(arguments, expressions)
-
-  override fun <T> visit(visitor: NodeVisitor<T>): T =
-    visitor.visitLambda(this)
-
-  override fun equals(other: Any?): Boolean {
-    if (other !is Lambda) return false
-    return other.arguments == arguments && other.expressions == expressions
-  }
-
-  override fun hashCode(): Int {
-    var result = arguments.hashCode()
-    result = 31 * result + expressions.hashCode()
-    result = 31 * result + type.hashCode()
-    return result
-  }
-}

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

@@ -29,9 +29,6 @@ class NodeCoalescer(val handler: (Node) -> Unit) : NodeVisitor<Unit> {
   override fun visitIntLiteral(node: IntLiteral): Unit =
     handle(node)
 
-  override fun visitLambda(node: Lambda): Unit =
-    handle(node)
-
   override fun visitLetAssignment(node: LetAssignment): Unit =
     handle(node)
 

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

@@ -15,7 +15,6 @@ enum class NodeType(val parent: NodeType? = null) {
   ImportDeclaration(Declaration),
   InfixOperation(Expression),
   IntLiteral(Expression),
-  Lambda(Expression),
   LetAssignment(Expression),
   ListLiteral(Expression),
   Parentheses(Expression),

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

@@ -20,8 +20,6 @@ interface NodeVisitor<T> {
 
   fun visitIntLiteral(node: IntLiteral): T
 
-  fun visitLambda(node: Lambda): T
-
   fun visitLetAssignment(node: LetAssignment): T
 
   fun visitListLiteral(node: ListLiteral): T

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

@@ -14,7 +14,6 @@ fun <T> NodeVisitor<T>.visit(node: Node): T =
     is If -> visitIf(node)
     is ImportDeclaration -> visitImportDeclaration(node)
     is IntLiteral -> visitIntLiteral(node)
-    is Lambda -> visitLambda(node)
     is ListLiteral -> visitListLiteral(node)
     is Parentheses -> visitParentheses(node)
     is PrefixOperation -> visitPrefixOperation(node)

evaluator/src/main/kotlin/gay/pizza/pork/evaluator/EvaluationVisitor.kt

@@ -27,24 +27,6 @@ class EvaluationVisitor(root: Scope) : NodeVisitor<Any> {
   override fun visitSymbolReference(node: SymbolReference): Any =
     currentScope.value(node.symbol.id)
 
-  override fun visitLambda(node: Lambda): CallableFunction {
-    return CallableFunction { arguments ->
-      currentScope = currentScope.fork()
-      for ((index, argumentSymbol) in node.arguments.withIndex()) {
-        currentScope.define(argumentSymbol.id, arguments.values[index])
-      }
-      try {
-        var value: Any? = null
-        for (expression in node.expressions) {
-          value = expression.visit(this)
-        }
-        value ?: None
-      } finally {
-        currentScope = currentScope.leave()
-      }
-    }
-  }
-
   override fun visitParentheses(node: Parentheses): Any =
     node.expression.visit(this)
 

examples/syntax.pork

@@ -1,55 +0,0 @@
-export func main() {
-  let three = 3
-  let two = 2
-
-  let calculateSimple = { in
-    (50 + three) * two
-  }
-
-  let calculateComplex = { in
-    three + two + 50
-  }
-
-  let multiply = { a, b in
-    a * b
-  }
-
-  // calculates the result
-  let calculateSimpleResult = calculateSimple()
-  let calculateComplexResult = calculateComplex()
-  let multiplyResult = multiply(50, 50)
-
-  let list = [10, 20, 30]
-  let trueValue = true
-  let falseValue = false
-
-  let invert = { value in
-    !value
-  }
-
-  let notEqual = { a, b in
-    a != b
-  }
-
-  let equal = { a, b in
-    a == b
-  }
-
-  let 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)
-}

frontend/src/main/kotlin/gay/pizza/pork/frontend/World.kt

@@ -8,11 +8,14 @@ import gay.pizza.pork.parser.TokenStreamSource
 import gay.pizza.pork.parser.Tokenizer
 
 class World(val contentSource: ContentSource) {
-  private val units = mutableMapOf<String, CompilationUnit>()
+  private val internalUnits = mutableMapOf<String, CompilationUnit>()
+
+  val units: List<CompilationUnit>
+    get() = internalUnits.values.toList()
 
   private fun loadOneUnit(path: String): CompilationUnit {
     val stableIdentity = contentSource.stableContentIdentity(path)
-    val cached = units[stableIdentity]
+    val cached = internalUnits[stableIdentity]
     if (cached != null) {
       return cached
     }

parser/src/main/kotlin/gay/pizza/pork/parser/Parser.kt

@@ -56,26 +56,6 @@ class Parser(source: PeekableSource<Token>, val attribution: NodeAttribution) {
     }
   }
 
-  private fun readLambda(): Lambda = within {
-    expect(TokenType.LeftCurly)
-    val arguments = mutableListOf<Symbol>()
-    while (!peek(TokenType.In)) {
-      val symbol = readSymbolRaw()
-      arguments.add(symbol)
-      if (next(TokenType.Comma)) {
-        continue
-      } else {
-        break
-      }
-    }
-    expect(TokenType.In)
-    val items = collect(TokenType.RightCurly) {
-      readExpression()
-    }
-    expect(TokenType.RightCurly)
-    Lambda(arguments, items)
-  }
-
   private fun readParentheses(): Parentheses = within {
     expect(TokenType.LeftParentheses)
     val expression = readExpression()
@@ -128,10 +108,6 @@ class Parser(source: PeekableSource<Token>, val attribution: NodeAttribution) {
         readSymbolCases()
       }
 
-      TokenType.LeftCurly -> {
-        readLambda()
-      }
-
       TokenType.LeftParentheses -> {
         readParentheses()
       }

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

@@ -82,34 +82,6 @@ class Printer(buffer: StringBuilder) : NodeVisitor<Unit> {
     visit(node.symbol)
   }
 
-  override fun visitLambda(node: Lambda) {
-    append("{")
-    if (node.arguments.isNotEmpty()) {
-      append(" ")
-      for ((index, argument) in node.arguments.withIndex()) {
-        visit(argument)
-        if (index + 1 != node.arguments.size) {
-          append(",")
-        }
-        append(" ")
-      }
-    } else {
-      append(" ")
-    }
-    append("in")
-    out.increaseIndent()
-    for (expression in node.expressions) {
-      appendLine()
-      visit(expression)
-    }
-
-    if (node.expressions.isNotEmpty()) {
-      appendLine()
-    }
-    out.decreaseIndent()
-    append("}")
-  }
-
   override fun visitParentheses(node: Parentheses) {
     append("(")
     visit(node.expression)

parser/src/main/kotlin/gay/pizza/pork/parser/TokenType.kt

@@ -24,7 +24,6 @@ enum class TokenType(vararg properties: TokenTypeProperty) {
   Comma(SingleChar(',')),
   False(Keyword("false"), KeywordFamily),
   True(Keyword("true"), KeywordFamily),
-  In(Keyword("in"), KeywordFamily),
   If(Keyword("if"), KeywordFamily),
   Then(Keyword("then"), KeywordFamily),
   Else(Keyword("else"), KeywordFamily),