- removed need for lhs field in stat node

- as a result deleted some more code

R=r
OCL=17449
CL=17449

usr/gri/pretty/node.go

@@ -173,7 +173,7 @@ export var BadType = NewType(0, Scanner.ILLEGAL);
 export type Stat struct {
 	pos, tok int;
 	init, post *Stat;
-	lhs, expr *Expr;
+	expr *Expr;
 	block *List;
 	decl *Decl;
 }

usr/gri/pretty/parser.go

@@ -904,13 +904,15 @@ func (P *Parser) ParseSimpleStat() *Node.Stat {
 		Scanner.SUB_ASSIGN, Scanner.MUL_ASSIGN, Scanner.QUO_ASSIGN,
 		Scanner.REM_ASSIGN, Scanner.AND_ASSIGN, Scanner.OR_ASSIGN,
 		Scanner.XOR_ASSIGN, Scanner.SHL_ASSIGN, Scanner.SHR_ASSIGN:
-		s = Node.NewStat(P.pos, P.tok);
+		// assignment
+		pos, tok := P.pos, P.tok;
 		P.Next();
-		s.lhs = x;
-		s.expr = P.ParseExpressionList();
-		if l, r := x.len(), s.expr.len(); l > 1 && r > 1 && l != r {
+		y := P.ParseExpressionList();
+		if xl, yl := x.len(), y.len(); xl > 1 && yl > 1 && xl != yl {
 			P.Error(x.pos, "arity of lhs doesn't match rhs");
 		}
+		s = Node.NewStat(x.pos, Scanner.EXPRSTAT);
+		s.expr = Node.NewExpr(pos, tok, x, y);
 
 	default:
 		var pos, tok int;

usr/gri/pretty/printer.go

@@ -232,10 +232,10 @@ func (P *Printer) Expr1(x *Node.Expr, prec1 int) {
 
 	case Scanner.PERIOD:
 		// selector or type guard
-		P.Expr1(x.x, 8);  // 8 == highest precedence
+		P.Expr1(x.x, Scanner.HighestPrec);
 		P.String(x.pos, ".");
 		if x.y != nil {
-			P.Expr1(x.y, 8);
+			P.Expr1(x.y, Scanner.HighestPrec);
 		} else {
 			P.String(0, "(");
 			P.Type(x.t);
@@ -244,14 +244,14 @@ func (P *Printer) Expr1(x *Node.Expr, prec1 int) {
 		
 	case Scanner.LBRACK:
 		// index
-		P.Expr1(x.x, 8);
+		P.Expr1(x.x, Scanner.HighestPrec);
 		P.String(x.pos, "[");
 		P.Expr1(x.y, 0);
 		P.String(0, "]");
 
 	case Scanner.LPAREN:
 		// call
-		P.Expr1(x.x, 8);
+		P.Expr1(x.x, Scanner.HighestPrec);
 		P.String(x.pos, "(");
 		P.Expr1(x.y, 0);
 		P.String(0, ")");
@@ -268,7 +268,7 @@ func (P *Printer) Expr1(x *Node.Expr, prec1 int) {
 		if x.x == nil {
 			// unary expression
 			P.Token(x.pos, x.tok);
-			P.Expr1(x.y, 7);  // 7 == unary operator precedence
+			P.Expr1(x.y, Scanner.UnaryPrec);
 		} else {
 			// binary expression: print ()'s if necessary
 			prec := Scanner.Precedence(x.tok);
@@ -289,7 +289,7 @@ func (P *Printer) Expr1(x *Node.Expr, prec1 int) {
 
 
 func (P *Printer) Expr(x *Node.Expr) {
-	P.Expr1(x, 0);
+	P.Expr1(x, Scanner.LowestPrec);
 }
 
 
@@ -372,18 +372,6 @@ func (P *Printer) Stat(s *Node.Stat) {
 		// declaration
 		P.Declaration(s.decl, false);
 
-	case Scanner.DEFINE, Scanner.ASSIGN, Scanner.ADD_ASSIGN,
-		Scanner.SUB_ASSIGN, Scanner.MUL_ASSIGN, Scanner.QUO_ASSIGN,
-		Scanner.REM_ASSIGN, Scanner.AND_ASSIGN, Scanner.OR_ASSIGN,
-		Scanner.XOR_ASSIGN, Scanner.SHL_ASSIGN, Scanner.SHR_ASSIGN:
-		// assignment
-		P.Expr(s.lhs);
-		P.Blank();
-		P.Token(s.pos, s.tok);
-		P.Blank();
-		P.Expr(s.expr);
-		P.semi = true;
-
 	case Scanner.INC, Scanner.DEC:
 		P.Expr(s.expr);
 		P.Token(s.pos, s.tok);

usr/gri/pretty/scanner.go

@@ -210,6 +210,13 @@ export func TokenString(tok int) string {
 }
 
 
+export const (
+	LowestPrec = -1;
+	UnaryPrec = 7;
+	HighestPrec = 8;
+)
+
+
 export func Precedence(tok int) int {
 	switch tok {
 	case COLON:
@@ -227,7 +234,7 @@ export func Precedence(tok int) int {
 	case MUL, QUO, REM, SHL, SHR, AND:
 		return 6;
 	}
-	return -1;
+	return LowestPrec;
 }