From bebd488df5327f1ffe212c50236d6198f313ff3c Mon Sep 17 00:00:00 2001 From: brian Date: Fri, 30 Jan 2004 07:03:40 +0000 Subject: [PATCH] 2003/07/09 01:19:45 darcs-hash:20040130070340-aa32f-f75bcda4c93cef3af88f69a59d0e0d980bc3aa70.gz --- src/org/xwt/js/Parser.java | 71 +++++++++++++++++++++++++------------------- 1 file changed, 40 insertions(+), 31 deletions(-) diff --git a/src/org/xwt/js/Parser.java b/src/org/xwt/js/Parser.java index 782c756..4abbdea 100644 --- a/src/org/xwt/js/Parser.java +++ b/src/org/xwt/js/Parser.java @@ -83,6 +83,8 @@ class Parser extends Lexer implements ByteCodes { static byte[] precedence = new byte[MAX_TOKEN + 1]; static boolean[] isRightAssociative = new boolean[MAX_TOKEN + 1]; + // Use this as the precedence when we want anything up to the comma + private final static int NO_COMMA = 2; static { isRightAssociative[ASSIGN] = isRightAssociative[ASSIGN_BITOR] = @@ -97,6 +99,8 @@ class Parser extends Lexer implements ByteCodes { isRightAssociative[ASSIGN_DIV] = isRightAssociative[ASSIGN_MOD] = true; + precedence[COMMA] = 1; + // 2 is intentionally left unassigned. we use minPrecedence==2 for comma separated lists precedence[ASSIGN] = precedence[ASSIGN_BITOR] = precedence[ASSIGN_BITXOR] = @@ -108,24 +112,20 @@ class Parser extends Lexer implements ByteCodes { precedence[ASSIGN_SUB] = precedence[ASSIGN_MUL] = precedence[ASSIGN_DIV] = - precedence[ASSIGN_MOD] = 1; - precedence[HOOK] = 2; - precedence[COMMA] = 3; - precedence[OR] = precedence[AND] = precedence[BANG] = 4; - precedence[GT] = precedence[GE] = 5; - precedence[BITOR] = 6; - precedence[BITXOR] = 7; - precedence[BITAND] = 8; - precedence[EQ] = precedence[NE] = 9; - precedence[LT] = precedence[LE] = precedence[TYPEOF] = 10; - precedence[SHEQ] = precedence[SHNE] = 11; + precedence[ASSIGN_MOD] = 3; + precedence[HOOK] = 4; + precedence[OR] = 5; + precedence[AND] = 6; + precedence[BITOR] = 7; + precedence[BITXOR] = 8; + precedence[BITAND] = 9; + precedence[EQ] = precedence[NE] = precedence[SHEQ] = precedence[SHNE] = 10; + precedence[LT] = precedence[LE] = precedence[GT] = precedence[GE] = 11; precedence[LSH] = precedence[RSH] = precedence[URSH] = 12; - precedence[ADD] = precedence[SUB] = 13; - precedence[MUL] = precedence[DIV] = precedence[MOD] = 14; - precedence[BITNOT] = 15; - precedence[INC] = precedence[DEC] = 16; - precedence[LP] = 17; - precedence[DOT] = precedence[LB] = 18; + precedence[ADD] = precedence[SUB] = 12; + precedence[MUL] = precedence[DIV] = precedence[MOD] = 13; + precedence[BITNOT] = precedence[BANG] = precedence[TYPEOF] = 14; + precedence[DOT] = precedence[LB] = precedence[LP] = precedence[INC] = precedence[DEC] = 15; } @@ -172,7 +172,7 @@ class Parser extends Lexer implements ByteCodes { if (peekToken() == COMMA || peekToken() == RB) b.add(parserLine, LITERAL, null); // for stuff like [1,,2,] else - startExpr(b, -1); // push the value onto the stack + startExpr(b, NO_COMMA); // push the value onto the stack b.add(parserLine, PUT); // put it into the array b.add(parserLine, POP); // discard the value remaining on the stack if (peekToken() == RB) break; @@ -218,7 +218,7 @@ class Parser extends Lexer implements ByteCodes { getToken(); b.add(parserLine, LITERAL, string); // grab the key consume(COLON); - startExpr(b, -1); // grab the value + startExpr(b, NO_COMMA); // grab the value b.add(parserLine, PUT); // put the value into the object b.add(parserLine, POP); // discard the remaining value if (peekToken() == RC) break; @@ -231,7 +231,7 @@ class Parser extends Lexer implements ByteCodes { case NAME: { b.add(parserLine, TOPSCOPE); b.add(parserLine, LITERAL, string); - continueExprAfterAssignable(b); + continueExprAfterAssignable(b,minPrecedence); break; } case FUNCTION: { @@ -298,19 +298,22 @@ class Parser extends Lexer implements ByteCodes { * expression that modifies the assignable. This method always * decreases the stack depth by exactly one element. */ - private void continueExprAfterAssignable(CompiledFunctionImpl b) throws IOException { + private void continueExprAfterAssignable(CompiledFunctionImpl b,int minPrecedence) throws IOException { int saveParserLine = parserLine; - _continueExprAfterAssignable(b); + _continueExprAfterAssignable(b,minPrecedence); parserLine = saveParserLine; } - private void _continueExprAfterAssignable(CompiledFunctionImpl b) throws IOException { + private void _continueExprAfterAssignable(CompiledFunctionImpl b,int minPrecedence) throws IOException { if (b == null) throw new Error("got null b; this should never happen"); int tok = getToken(); + if (minPrecedence != -1 && (precedence[tok] < minPrecedence || (precedence[tok] == minPrecedence && !isRightAssociative[tok]))) + // force the default case + tok = -1; switch(tok) { case ASSIGN_BITOR: case ASSIGN_BITXOR: case ASSIGN_BITAND: case ASSIGN_LSH: case ASSIGN_RSH: case ASSIGN_URSH: case ASSIGN_ADD: case ASSIGN_SUB: case ASSIGN_MUL: case ASSIGN_DIV: case ASSIGN_MOD: { b.add(parserLine, GET_PRESERVE); - startExpr(b, -1); + startExpr(b, precedence[tok]); // tok-1 is always s/^ASSIGN_// (0 is BITOR, 1 is ASSIGN_BITOR, etc) b.add(parserLine, tok - 1, tok-1==ADD ? new Integer(2) : null); b.add(parserLine, PUT); @@ -323,7 +326,7 @@ class Parser extends Lexer implements ByteCodes { break; } case ASSIGN: { - startExpr(b, -1); + startExpr(b, precedence[tok]); b.add(parserLine, PUT); b.add(parserLine, SWAP); b.add(parserLine, POP); @@ -409,27 +412,33 @@ class Parser extends Lexer implements ByteCodes { case DOT: { consume(NAME); b.add(parserLine, LITERAL, string); - continueExprAfterAssignable(b); + continueExprAfterAssignable(b,minPrecedence); break; } case LB: { // subscripting (not array constructor) startExpr(b, -1); consume(RB); - continueExprAfterAssignable(b); + continueExprAfterAssignable(b,minPrecedence); break; } case HOOK: { b.add(parserLine, JF, new Integer(0)); // jump to the if-false expression int size = b.size(); - startExpr(b, -1); // write the if-true expression + startExpr(b, minPrecedence); // write the if-true expression b.add(parserLine, JMP, new Integer(0)); // if true, jump *over* the if-false expression b.set(size - 1, new Integer(b.size() - size + 1)); // now we know where the target of the jump is consume(COLON); size = b.size(); - startExpr(b, -1); // write the if-false expression + startExpr(b, minPrecedence); // write the if-false expression b.set(size - 1, new Integer(b.size() - size + 1)); // this is the end; jump to here break; } + case COMMA: { + // pop the result of the previous expression, it is ignored + b.add(parserLine,POP); + startExpr(b,-1); + break; + } default: { pushBackToken(); return; @@ -445,7 +454,7 @@ class Parser extends Lexer implements ByteCodes { while(peekToken() != RP) { i++; if (peekToken() != COMMA) { - startExpr(b, -1); + startExpr(b, NO_COMMA); if (peekToken() == RP) break; } consume(COMMA); @@ -504,7 +513,7 @@ class Parser extends Lexer implements ByteCodes { b.add(parserLine, DECLARE, string); // declare it if (peekToken() == ASSIGN) { // if there is an '=' after the variable name consume(ASSIGN); - startExpr(b, -1); + startExpr(b, NO_COMMA); b.add(parserLine, PUT); // assign it b.add(parserLine, POP); // clean the stack } else { -- 1.7.10.4