Fix nested stacked exprs and parse members

1 files changed, 72 insertions, 41 deletions

diff --git a/pkg/lang/parser/exprs.go b/pkg/lang/parser/exprs.go
index 80b0fd6..48d1a8c 100644
--- a/pkg/lang/parser/exprs.go
+++ b/pkg/lang/parser/exprs.go
@@ -65,7 +65,7 @@ func (p *Parser) parseUnaryExpr() (ast.Expr, error) {
 func (p *Parser) parsePostfixExpr() (ast.Expr, error) {
 	// PostfixExpr = SubscriptionExpr | CallExpr
 
-	obj, err := p.parseUnitExpr()
+	obj, err := p.parseMemberExpr()
 	if err != nil {
 		return ast.Expr{}, err
 	}
@@ -81,42 +81,41 @@ func (p *Parser) parsePostfixExpr() (ast.Expr, error) {
 }
 
 func (p *Parser) parseArrayIndexExpr(obj ast.Expr) (ast.Expr, error) {
-	// SubscriptionExpr = UnitExpr ( "[" Expr "]" )*
+	// SubscriptionExpr = MemberExpr ( "[" Expr "]" )*
 
-	if _, err := p.expect(token.LBracket); err != nil {
-		return ast.Expr{}, err
-	}
+	for p.peek().Kind == token.LBracket {
+		p.next()
 
-	index, err := p.parseExpr()
-	if err != nil {
-		return ast.Expr{}, err
-	}
+		index, err := p.parseExpr()
+		if err != nil {
+			return ast.Expr{}, err
+		}
 
-	if _, err := p.expect(token.RBracket); err != nil {
-		return ast.Expr{}, err
-	}
+		if _, err := p.expect(token.RBracket); err != nil {
+			return ast.Expr{}, err
+		}
 
-	return ast.Expr{
-		At:   obj.At,
-		Kind: ast.ExprKindSubscription,
-		Value: ast.ExprSubscription{
-			Obj: obj,
-			Key: index,
-		},
-	}, nil
+		obj = ast.Expr{
+			At:   obj.At,
+			Kind: ast.ExprKindSubscription,
+			Value: ast.ExprSubscription{
+				Obj: obj,
+				Key: index,
+			},
+		}
+	}
 
+	return obj, nil
 }
 
 func (p *Parser) parseCallExpr(callee ast.Expr) (ast.Expr, error) {
-	// CallExpr = UnitExpr ( "(" ( Expr ( "," Expr )* )? ")" )*
+	// CallExpr = MemberExpr ( "(" ( Expr ( "," Expr )* )? ")" )*
 
-	if _, err := p.expect(token.LParen); err != nil {
-		return ast.Expr{}, err
-	}
+	for p.peek().Kind == token.LParen {
+		p.next()
 
-	args := []ast.Expr{}
-	if p.peek().Kind != token.RParen {
-		for {
+		args := []ast.Expr{}
+		for p.peek().Kind != token.RParen {
 			arg, err := p.parseExpr()
 			if err != nil {
 				return ast.Expr{}, err
@@ -124,29 +123,61 @@ func (p *Parser) parseCallExpr(callee ast.Expr) (ast.Expr, error) {
 
 			args = append(args, arg)
 
-			if p.peek().Kind == token.RParen {
+			if p.peek().Kind == token.Comma {
+				p.next()
+			} else {
 				break
 			}
+		}
 
-			if _, err := p.expect(token.Comma); err != nil {
-				return ast.Expr{}, err
-			}
+		if _, err := p.expect(token.RParen); err != nil {
+			return ast.Expr{}, err
+		}
+
+		callee = ast.Expr{
+			At:   callee.At,
+			Kind: ast.ExprKindCall,
+			Value: ast.ExprCall{
+				Callee: callee,
+				Args:   args,
+			},
 		}
 	}
 
-	if _, err := p.expect(token.RParen); err != nil {
+	return callee, nil
+}
+
+func (p *Parser) parseMemberExpr() (ast.Expr, error) {
+	// MemberExpr = UnitExpr ( "." Ident )*
+
+	left, err := p.parseUnitExpr()
+	if err != nil {
 		return ast.Expr{}, err
 	}
 
-	return ast.Expr{
-		At:   callee.At,
-		Kind: ast.ExprKindCall,
-		Value: ast.ExprCall{
-			Callee: callee,
-			Args:   args,
-		},
-	}, nil
+	for {
+		if p.peek().Kind != token.Dot {
+			break
+		}
+
+		p.next()
+
+		node, err := p.parseIdent()
+		if err != nil {
+			return ast.Expr{}, err
+		}
 
+		left = ast.Expr{
+			At:   left.At,
+			Kind: ast.ExprKindMember,
+			Value: ast.ExprMember{
+				Obj: left,
+				Key: node,
+			},
+		}
+	}
+
+	return left, nil
 }
 
 func (p *Parser) parseUnitExpr() (ast.Expr, error) {
@@ -176,7 +207,7 @@ func (p *Parser) parseUnitExpr() (ast.Expr, error) {
 	case token.KwTrue, token.KwFalse, token.KwNull, token.KwThis:
 		return p.parseValueLitExpr()
 	default:
-		panic(fmt.Errorf("unexpected token '%v', wanted unit expression start", p.peek()))
+		panic(fmt.Errorf("unexpected token '%v', wanted unit expression start", p.peek().Kind))
 	}
 }