Fixed error message for types in match exprs not being unions

analyzer/control-flow_test.go

@@ -68,7 +68,7 @@ U: (| Int F64)
 
 func TestMatchErrNotUnion (test *testing.T) {
 testStringErr (test,
-"type U is not a union", 3, 24,
+"type U is not a union", 3, 30,
 `
 U: Int
 [matchToInt u:U]:Int = match u

analyzer/expression.go

@@ -549,7 +549,7 @@ func (this *Tree) analyzeOperation (
 		
 	case entity.OperatorLeftShift, entity.OperatorRightShift:
 		if len(operation.Arguments) != 2 { return wrongArgCount() }
-		if !isInteger(into)         { return wrongInto()     }
+		if !isInteger(into)              { return wrongInto()     }
 
 		arg, err := this.analyzeExpression(into, mode, operation.Arguments[0])
 		if err != nil { return nil, err }
@@ -594,7 +594,8 @@ func (this *Tree) analyzeBlock (
 
 	if len(block.Steps) == 0 && into != nil {
 		return nil, errors.Errorf (
-			block.Position(), "block must have at least one statement")
+			block.Position(),
+			"block must have at least one statement")
 	}
 
 	final := len(block.Steps) - 1
@@ -603,7 +604,8 @@ func (this *Tree) analyzeBlock (
 			expression, ok := step.(entity.Expression)
 			if !ok {
 				return nil, errors.Errorf (
-					block.Position(), "expected expression")
+					block.Position(),
+					"expected expression")
 			}
 			
 			step, err := this.analyzeExpression(into, strict, expression)
@@ -642,14 +644,16 @@ func (this *Tree) analyzeMemberAccess (
 		referenced, ok := ReduceToBase(sourceTypeAny.Referenced).(*entity.TypeStruct)
 		if !ok {
 			return nil, errors.Errorf (
-				access.Position(), "cannot access members of %v",
+				access.Position(),
+				"cannot access members of %v",
 				source)
 		}
 		sourceType          = referenced
 		qualifiedSourceType = sourceTypeAny.Referenced
 	default:
 		return nil, errors.Errorf (
-			access.Position(), "cannot access members of %v",
+			access.Position(),
+			"cannot access members of %v",
 			source)
 	}
 
@@ -723,10 +727,8 @@ func (this *Tree) analyzeMatch (
 	match.Value = value
 	rawUnion, ok := this.isUnion(value.Type())
 	if !ok {
-		// FIXME: add Position() method to Expression, then change this
-		// error message (and others) #53
 		return nil, errors.Errorf (
-			match.Position(), "type %v is not a union",
+			match.Value.Position(), "type %v is not a union",
 			value.Type())
 	}