Add untested constant access analysis

analyzer/expression-multiplex.go

@@ -14,6 +14,8 @@ func (this *Tree) analyzeExpression (
 	switch expression := expression.(type) {
 	case *entity.Assignment:
 		return this.analyzeAssignment(expression)
+	case *entity.Constant:
+		return this.analyzeConstant(into, mode, expression)
 	case *entity.Variable:
 		return this.analyzeVariable(into, mode, expression)
 	case *entity.Declaration:

analyzer/expression.go

@@ -33,6 +33,47 @@ func (this *Tree) analyzeAssignment (
 	return assignment, nil
 }
 
+func (this *Tree) analyzeConstant (
+	into     entity.Type,
+	mode     strictness,
+	constant *entity.Constant,
+) (
+	entity.Expression,
+	error,
+) {
+	// get typedef
+	unit, err := this.resolveNickname(constant.Position(), constant.UnitNickname)
+	if err != nil { return nil, err }
+	typedef, err := this.analyzeTypedef(constant.Position(), entity.Key {
+			Unit: unit,
+			Name: constant.TypeName,
+		}, false) // TODO perhaps we should accept incomplete ones?
+	if err != nil { return nil, err }
+	constant.Unit = typedef.Unit()
+	constant.Ty   = into
+	
+	// check access permissions
+	if typedef.Acc == entity.AccessPrivate && typedef.Unit() != this.unit {
+		return nil, errors.Errorf (
+			constant.Position(), "type %v::%v is private",
+			constant.UnitNickname, constant.TypeName)
+	}
+
+	// get declaration
+	declaration, ok := typedef.ConstantMap[constant.Name]
+	if !ok {
+		return nil, errors.Errorf (
+			constant.Position(), "no constant %v",
+			constant)
+	}
+	constant.Declaration = declaration
+
+	err = this.canAssign(constant.Position(), into, mode, declaration.Type())
+	if err != nil { return nil, err }
+
+	return constant, nil
+}
+
 func (this *Tree) analyzeVariable (
 	into     entity.Type,
 	mode     strictness,

analyzer/type.go

@@ -59,8 +59,9 @@ func (this *Tree) analyzeTypedef (
 		if constant.Value == nil {
 			if !isNumeric(definition.Type) {
 				return nil, errors.Errorf (
-					pos, "cannot fill in constant values for non-numeric type %v",
-					definition.Type)
+					constant.Position(),
+					"cannot fill in constant value for non-numeric type %v",
+					definition.Name)
 			}
 			constant.Value = &entity.LiteralInt {
 				Pos:   pos,

entity/expression.go

@@ -719,8 +719,9 @@ type Constant struct {
 	Name         string
 	
 	// Semantics
-	Ty   Type
-	Unit uuid.UUID
+	Ty          Type
+	Unit        uuid.UUID
+	Declaration *ConstantDeclaration
 }
 func (*Constant) expression(){}
 func (this *Constant) Position () errors.Position { return this.Pos }