Removed Void as a concept

analyzer/assignment.go

@@ -66,8 +66,7 @@ func (this *Tree) canAssign (
 		}
 
 	// base type
-	case *entity.TypeVoid,
-		*entity.TypePointer,
+	case *entity.TypePointer,
 		*entity.TypeSlice,
 		*entity.TypeArray,
 		*entity.TypeStruct,
@@ -190,8 +189,7 @@ func (this *Tree) areStructurallyEquivalent (left, right entity.Type) bool {
 		}
 
 	// terminals
-	case *entity.TypeVoid,
-		*entity.TypeInt,
+	case *entity.TypeInt,
 		*entity.TypeFloat,
 		*entity.TypeWord,
 		*entity.TypeBool:

analyzer/expression.go

@@ -174,7 +174,7 @@ func (this *Tree) analyzeSubscript (
 		subscript.Slice)
 	if err != nil { return nil, err }
 	subscript.Slice = slice
-	subscript.Ty    = voidIfNil(into)
+	subscript.Ty    = into
 
 	offset, err := this.analyzeExpression (
 		builtinType("Index"), weak,
@@ -232,7 +232,7 @@ func (this *Tree) analyzeDereference (
 		dereference.Pointer)
 	if err != nil { return nil, err }
 	dereference.Pointer = pointer
-	dereference.Ty      = voidIfNil(into)
+	dereference.Ty      = into
 
 	return pointer, nil
 }
@@ -471,7 +471,6 @@ func (this *Tree) analyzeBlock (
 	}
 
 	final := len(block.Steps) - 1
-	block.Ty = &entity.TypeVoid { }
 	for index, step := range block.Steps {
 		if index == final && into != nil {
 			expression, ok := step.(entity.Expression)
@@ -567,7 +566,7 @@ func (this *Tree) analyzeLoop (
 	entity.Expression,
 	error,
 ) {
-	loop.Ty = voidIfNil(into)
+	loop.Ty = into
 	this.pushLoop(loop)
 	defer this.popLoop()
 
@@ -598,7 +597,7 @@ func (this *Tree) analyzeBreak (
 	}
 	brk.Loop = loop
 
-	if !loop.Type().Equals(&entity.TypeVoid { }) && brk.Value == nil {
+	if loop.Type() != nil && brk.Value == nil {
 		return nil, participle.Errorf (
 			brk.Pos,
 			"break statement must have value")
@@ -634,7 +633,7 @@ func (this *Tree) analyzeReturn (
 		ty = ret.Declaration.(*entity.Method).Signature.Return
 	}
 
-	if !ty.Equals(&entity.TypeVoid { }) && ret.Value == nil {
+	if ty != nil && ret.Value == nil {
 		return nil, participle.Errorf (
 			ret.Pos,
 			"break statement must have value")

analyzer/method.go

@@ -103,8 +103,7 @@ func (this *Tree) analyzeMethodOrBehavior (
 		ty := ty.(*entity.TypePointer)
 		return this.analyzeMethodOrBehavior(pos, ty.Referenced, name)
 	
-	case *entity.TypeVoid,
-		*entity.TypeSlice,
+	case *entity.TypeSlice,
 		*entity.TypeArray,
 		*entity.TypeStruct,
 		*entity.TypeInt,

analyzer/type.go

@@ -60,9 +60,7 @@ func (this *Tree) analyzeTypeInternal (
 	error,
 ) {
 	// edge cases
-	void := &entity.TypeVoid { }
-	if ty == nil       { return void, nil }
-	if ty.Equals(void) { return ty,   nil }
+	if ty == nil { return nil, nil }
 	var err error
 
 	// if we are analyzing a typedef, we will need to update incomplete type
@@ -201,11 +199,3 @@ func (this *Tree) analyzeBehavior (behavior *entity.Signature) (*entity.Signatur
 	behavior.Return, err = this.analyzeType(behavior.Return, false)
 	return behavior, err
 }
-
-func voidIfNil (ty entity.Type) entity.Type {
-	if ty == nil {
-		return &entity.TypeVoid { }
-	} else {
-		return ty
-	}
-}

entity/expression.go

@@ -365,7 +365,7 @@ type Break struct {
 }
 func (*Break) expression(){}
 func (*Break) statement(){}
-func (this *Break) Type () Type { return &TypeVoid { } }
+func (this *Break) Type () Type { return nil }
 func (this *Break) String () string {
 	if this.Value == nil {
 		return "[break]"
@@ -388,7 +388,7 @@ type Return struct {
 }
 func (*Return) expression(){}
 func (*Return) statement(){}
-func (this *Return) Type () Type { return &TypeVoid { } }
+func (this *Return) Type () Type { return nil }
 func (this *Return) String () string {
 	if this.Value == nil {
 		return "[return]"

entity/type.go

@@ -11,15 +11,6 @@ type Type interface {
 	ty ()
 }
 
-// TypeVoid represents the absence of a type.
-type TypeVoid struct { }
-func (*TypeVoid) ty(){}
-func (*TypeVoid) Equals (ty Type) bool {
-	_, equals := ty.(*TypeVoid)
-	return equals
-}
-func (*TypeVoid) String () string { return "Void" }
-
 // TypeNamed refers to a user-defined or built in named type.
 type TypeNamed struct {
 	Pos lexer.Position