-
- public Expr parseSingleExpr(Expr prefix, int minPrecedence) throws IOException {
- Expr e1 = null, e2 = null, e3 = null, head = null, tail = null, ret = null;
-
- int tok = peekToken();
- if (minPrecedence > 0 &&
- tok < precedence.length &&
- precedence[tok] != 0 &&
- (isRightAssociative[tok] ?
- (precedence[tok] < minPrecedence) :
- (precedence[tok] <= minPrecedence))) {
- return prefix;
- }
- getToken();
- int curLine = line;
-
- // these case arms match the precedence of operators; each arm is a precedence level.
- switch (tok) {
-
- case VAR: {
- if (prefix != null) { pushBackToken(); return prefix; }
- ByteCode b = new ByteCode(curLine);
- b.add(b.THIS, NO_ARG);
- while(true) {
- consume(NAME);
- String name = string;
- b.add(b.DECLARE, name);
- if (peekToken() == ASSIGN) {
- b.add(b.LITERAL, name);
- consume(ASSIGN);
- b.add(b.EXPR, parseMaximalExpr());
- b.add(b.PUT, NO_ARG);
- b.add(b.POP, NO_ARG);
- }
- if (peekToken() != COMMA) break;
- consume(COMMA);
- }
- return b;
- }
-
- case IN: pushBackToken(); return prefix;
-
- case IF: {
- if (prefix != null) { pushBackToken(); return prefix; }
- ByteCode b = new ByteCode(curLine);
- consume(LP);
- b.add(b.EXPR, parseMaximalExpr());
- consume(RP);
- b.add(b.JF, new Integer(3));
- b.add(b.EXPR, parseBlock(false));
- b.add(b.JMP, new Integer(2));
- if (peekToken() != ELSE) return b.add(b.LITERAL, null);
- consume(ELSE);
- b.add(b.EXPR, parseBlock(false));
- return b;
- }
-
- // FIXME: ugly hack!!
- case ASSIGN_BITOR: if (tok == ASSIGN_BITOR) tok = BITOR;
- case ASSIGN_BITXOR: if (tok == ASSIGN_BITXOR) tok = BITXOR;
- case ASSIGN_BITAND: if (tok == ASSIGN_BITAND) tok = BITAND;
- case ASSIGN_LSH: if (tok == ASSIGN_LSH) tok = LSH;
- case ASSIGN_RSH: if (tok == ASSIGN_RSH) tok = RSH;
- case ASSIGN_URSH: if (tok == ASSIGN_URSH) tok = URSH;
- case ASSIGN_ADD: if (tok == ASSIGN_ADD) tok = ADD;
- case ASSIGN_SUB: if (tok == ASSIGN_SUB) tok = SUB;
- case ASSIGN_MUL: if (tok == ASSIGN_MUL) tok = MUL;
- case ASSIGN_DIV: if (tok == ASSIGN_DIV) tok = DIV;
- case ASSIGN_MOD: if (tok == ASSIGN_MOD) tok = MOD;
- {
- ByteCode b = (ByteCode)prefix;
- b.set(b.size() - 1, b.GET_PRESERVE, new Boolean(true));
- b.add(b.EXPR, parseMaximalExpr(null, precedence[tok]));
- b.add(tok, NO_ARG);
- b.add(b.PUT, NO_ARG);
- b.add(b.SWAP, NO_ARG);
- b.add(b.POP, NO_ARG);
- return b;
- }
-
- case INC: case DEC:
- if (prefix == null) {
- // prefix
- ByteCode b = (ByteCode)parseMaximalExpr(null, precedence[tok]);
- b.set(b.size() - 1, tok, new Boolean(true));
- return b;
- } else {
- // postfix
- ByteCode b = (ByteCode)prefix;
- b.set(b.size() - 1, tok, new Boolean(false));
- return b;
- }
-
- case LP:
- if (prefix == null) { // grouping
- ByteCode b = new ByteCode(curLine, ByteCode.EXPR, parseMaximalExpr());
- consume(RP);
- return b;
-
- } else { // invocation
- ByteCode b = new ByteCode(curLine);
- int i = 0;
- b.add(b.EXPR, prefix);
- while(peekToken() != RP) {
- b.add(b.EXPR, parseMaximalExpr());
- i++;
- if (peekToken() == RP) break;
- consume(COMMA);
- }
- consume(RP);
- b.add(b.CALL, new Integer(i));
- return b;
- }
-
- case BANG: case BITNOT: case INSTANCEOF: case TYPEOF: {
- if (prefix != null) { pushBackToken(); return prefix; }
- ByteCode b = new ByteCode(curLine);
- b.add(b.EXPR, parseMaximalExpr(null, precedence[tok]));
- b.add(tok, NO_ARG);
- return b;
- }
-
- case SUB:
- if (prefix == null && peekToken() == NUMBER) {
- getToken();
- return new ByteCode(curLine, ByteCode.LITERAL, new Double(number.doubleValue() * -1));
- } // else fall through
- case BITOR: case BITXOR: case BITAND: case SHEQ: case SHNE: case LSH:
- case RSH: case URSH: case ADD: case MUL: case DIV: case MOD:
- case GT: case GE: case EQ: case NE: case LT: case LE: {
- if (prefix == null) throw new ParserException("the " + codeToString[tok] + " token cannot start an expression");
- ByteCode b = new ByteCode(curLine);
- b.add(b.EXPR, prefix);
- b.add(b.EXPR, parseMaximalExpr(null, precedence[tok]));
- b.add(tok, NO_ARG);
- return b;
- }
-
- // includes short-circuit logic
- case OR: case AND: {
- if (prefix == null) throw new ParserException("the " + codeToString[tok] + " token cannot start an expression");
- ByteCode b = new ByteCode(curLine);
- b.add(b.LITERAL, tok == AND ? new Boolean(false) : new Boolean(true));
- b.add(b.EXPR, prefix);
- b.add(tok == AND ? b.JF : b.JT, new Integer(3));
- b.add(b.POP, NO_ARG);
- b.add(b.EXPR, parseMaximalExpr(null, precedence[tok]));
- return b;
- }
-
- case ASSIGN: {
- if (prefix == null) throw new ParserException("the " + codeToString[tok] + " token cannot start an expression");
- ByteCode b = new ByteCode(curLine);
- b.add(b.THIS, NO_ARG);
- b.add(b.LITERAL, prefix.string); // FIXME, this is ass-ugly
- b.add(b.EXPR, parseMaximalExpr(null, precedence[ASSIGN]));
- b.add(b.PUT, NO_ARG);
- b.add(b.SWAP, NO_ARG);
- b.add(b.POP, NO_ARG);
- return b;
- }
-
- case WITH: throw new ParserException("XWT does not allow the WITH keyword");
- case VOID: case RESERVED: throw new ParserException("reserved word that you shouldn't be using");
-
- case NUMBER:
- if (prefix != null) { pushBackToken(); return prefix; }
- return new ByteCode(curLine, ByteCode.LITERAL, number);
-
- case STRING:
- if (prefix != null) { pushBackToken(); return prefix; }
- return new ByteCode(curLine, ByteCode.LITERAL, string);
-
- case NULL: case TRUE: case FALSE: case NOP:
- if (prefix != null) { pushBackToken(); return prefix; }
- return new ByteCode(curLine, ByteCode.LITERAL, (tok == NULL || tok == NOP) ? null : new Boolean(tok == TRUE));
-
- case COMMA: pushBackToken(); return prefix;
-
- case THIS:
- if (prefix != null) { pushBackToken(); return prefix; }
- return new ByteCode(curLine, ByteCode.THIS, NO_ARG);
-
- // potential lvalues
-
- case NAME: {
- if (prefix != null) { pushBackToken(); return prefix; }
- String name = string;
- ByteCode b = new ByteCode(curLine);
- if (peekToken() == ASSIGN) {
- consume(ASSIGN);
- b.add(ByteCode.THIS, NO_ARG);
- b.add(ByteCode.LITERAL, name);
- b.add(ByteCode.EXPR, parseMaximalExpr(null, minPrecedence));
- b.add(ByteCode.PUT, NO_ARG);
- b.add(ByteCode.SWAP, NO_ARG);
- b.add(ByteCode.POP, NO_ARG);
- return b;
- } else {
- b.add(ByteCode.THIS, NO_ARG);
- b.add(ByteCode.LITERAL, name);
- b.add(ByteCode.GET, NO_ARG);
- return parseMaximalExpr(b, minPrecedence);
- }
- }
-
- case DOT: {
- consume(NAME);
- String target = string;
- ByteCode b = new ByteCode(curLine);
- b.add(b.EXPR, prefix);
- if (peekToken() == ASSIGN) {
- consume(ASSIGN);
- Expr val = parseMaximalExpr();
- b.add(b.LITERAL, target);
- b.add(b.EXPR, val);
- b.add(b.PUT, NO_ARG);
- b.add(b.SWAP, NO_ARG);
- b.add(b.POP, NO_ARG);
- } else {
- b.add(b.LITERAL, target);
- b.add(b.GET, NO_ARG);
- }
- return b;
- }
-
- case LB: {
- ByteCode b = new ByteCode(curLine);
- if (prefix == null) {
- b.add(b.ARRAY, new Integer(0));
- int i = 0;
- while(true) {
- Expr e = parseMaximalExpr();
- if (e == null && peekToken() == RB) { consume(RB); return b; }
- b.add(b.LITERAL, new Integer(i++));
- if (e == null) b.add(b.LITERAL, null);
- else b.add(b.EXPR, e);
- b.add(b.PUT, NO_ARG);
- b.add(b.POP, NO_ARG);
- if (peekToken() == RB) { consume(RB); return b; }
- consume(COMMA);
- }
- } else {
- b.add(b.EXPR, prefix);
- b.add(b.EXPR, parseMaximalExpr());
- consume(RB);
- if (peekToken() == ASSIGN) {
- consume(ASSIGN);
- b.add(b.EXPR, parseMaximalExpr());
- b.add(b.PUT, NO_ARG);
- b.add(b.SWAP, NO_ARG);
- b.add(b.POP, NO_ARG);
- } else {
- b.add(b.GET, NO_ARG);
- }
- return b;
- }
- }
-
- case LC: {
- if (prefix != null) { pushBackToken(); return prefix; }
- ByteCode b = new ByteCode(curLine);
- b.add(b.OBJECT, null);
- if (peekToken() == RC) { consume(RC); return b; }
- while(true) {
- if (peekToken() != NAME && peekToken() != STRING) throw new Error("expected NAME or STRING");
- getToken();
- b.add(b.LITERAL, string);
- consume(COLON);
- b.add(b.EXPR, parseMaximalExpr());
- b.add(b.PUT, NO_ARG);
- b.add(b.POP, NO_ARG);
- if (peekToken() == RC) { consume(RC); return b; }
- consume(COMMA);
- if (peekToken() == RC) { consume(RC); return b; }
- }
- }
-
- case HOOK: {
- ByteCode b = new ByteCode(curLine);
- b.add(b.EXPR, prefix);
- b.add(b.JF, new Integer(3));
- b.add(b.EXPR, parseMaximalExpr());
- b.add(b.JMP, new Integer(2));
- consume(COLON);
- b.add(b.EXPR, parseMaximalExpr());
- return b;
- }
-
- case FUNCTION: {
- if (prefix != null) { pushBackToken(); return prefix; }
- consume(LP);
- ByteCode b = new ByteCode(curLine);
- int numArgs = 0;
- b.add(b.THIS, NO_ARG);
- b.add(b.SWAP, NO_ARG);
- b.add(b.LITERAL, "arguments");
- b.add(b.LITERAL, "arguments");
- b.add(b.DECLARE, NO_ARG);
- b.add(b.SWAP, NO_ARG);
- b.add(b.PUT, NO_ARG);
- b.add(b.SWAP, NO_ARG);
- b.add(b.POP, NO_ARG);
- if (peekToken() == RP) consume(RP);
- else while(true) {
- if (peekToken() == COMMA) {
- consume(COMMA);
- } else {
- consume(NAME);
-
- // declare the name
- b.add(b.LITERAL, string);
- b.add(b.DECLARE, NO_ARG);
-
- // retrieve it from the arguments array
- b.add(b.LITERAL, new Integer(numArgs));
- b.add(b.GET_PRESERVE, NO_ARG);
- b.add(b.SWAP, NO_ARG);
- b.add(b.POP, NO_ARG);
-
- // put it to the current scope
- b.add(b.THIS, NO_ARG);
- b.add(b.SWAP, NO_ARG);
- b.add(b.LITERAL, string);
- b.add(b.SWAP, NO_ARG);
- b.add(b.PUT, NO_ARG);
-
- // clean the stack
- b.add(b.POP, NO_ARG);
- b.add(b.POP, NO_ARG);
-
- if (peekToken() == RP) { consume(RP); break; }
- consume(COMMA);
- }
- numArgs++;
- }
- // pop off the arguments array
- b.add(b.POP, NO_ARG);
- parseBlock(true, b);
- return new ByteCode(curLine, b.FUNCTION, b);
- }
-
- case WHILE: {
- if (prefix != null) { pushBackToken(); return prefix; }
- consume(LP);
- ByteCode r = new ByteCode(curLine);
- ByteCode loop = new ByteCode(curLine);
- r.add(loop.LOOP, loop);
- r.add(r.LITERAL, null);
-
- loop.add(loop.EXPR, parseMaximalExpr());
- loop.add(loop.JT, new Integer(2));
- loop.add(Lexer.BREAK, NO_ARG);
- consume(RP);
- parseBlock(false, loop);
-
- // if we fall out of the end, definately continue
- loop.add(CONTINUE, NO_ARG);
- return r;
- }
-
- case SWITCH: {
- if (prefix != null) { pushBackToken(); return prefix; }
- consume(LP);
- ByteCode r = new ByteCode(curLine);
- ByteCode loop = new ByteCode(curLine);
- r.add(loop.LOOP, loop);
- r.add(r.LITERAL, null);
- loop.add(loop.EXPR, parseMaximalExpr());
- consume(RP);
- consume(LC);
- while(true) {
- Expr caseExpr;
- tok = getToken();
- if (tok == CASE) {
- loop.add(loop.DUP, NO_ARG);
- loop.add(loop.EXPR, parseMaximalExpr());
- loop.add(EQ, NO_ARG);
- loop.add(loop.JF, new Integer(2));
- } else if (tok != DEFAULT) throw new ParserException("expected CASE or DEFAULT");
- consume(COLON);
- ByteCode b = new ByteCode(curLine);
- while(peekToken() != CASE && peekToken() != DEFAULT && peekToken() != RC) {
- if ((e1 = parseBlock(false)) == null) break;
- b.add(b.EXPR, e1);
- }
- loop.add(loop.EXPR, b);
- if (peekToken() == RC) {
- consume(RC);
- r.add(BREAK, NO_ARG);
- return r;
- }
- }
- }
-
- case DO: {
- if (prefix != null) { pushBackToken(); return prefix; }
- ByteCode r = new ByteCode(curLine);
- ByteCode loop = new ByteCode(curLine);
- r.add(loop.LOOP, loop);
- r.add(r.LITERAL, null);
-
- parseBlock(false, loop);
- consume(WHILE);
- consume(LP);
- loop.add(loop.EXPR, parseMaximalExpr());
- loop.add(loop.JT, new Integer(2));
- loop.add(Lexer.BREAK, NO_ARG);
- loop.add(Lexer.CONTINUE, NO_ARG);
- consume(RP);
- consume(SEMI);
- return r;
- }
-
- // Needs break //
-
- case FOR:
- if (prefix != null) { pushBackToken(); return prefix; }
- if (getToken() != LP) throw new ParserException("expected left paren");
- e1 = parseMaximalExpr();
- if (peekToken() == IN) {
- getToken();
- e2 = parseMaximalExpr();
- if (getToken() != RP) throw new ParserException("expected right paren");
- return new Expr(curLine, FOR, new Expr(curLine, IN, e1.left, e2), parseBlock(false));
-
- } else {
- Expr initExpr = e1;
- if (initExpr == null) initExpr = new Expr(curLine, NULL);
- consume(SEMI);
- Expr whileExpr = parseMaximalExpr();
- consume(SEMI);
- Expr incExpr = parseMaximalExpr();
- consume(RP);
- Expr body = parseBlock(false);
- Expr loop = new Expr(curLine, WHILE, whileExpr, body);
- ExprList list = new ExprList(curLine, LC);
- list.add(initExpr);
- ExprList list2 = new ExprList(curLine, WHILE);
- list.add(list2);
- list2.add(whileExpr);
- list2.add(body);
- list2.add(incExpr);
- return list;
- }
-
- case TRY: {
- // We deliberately allow you to omit braces in catch{}/finally{} if they are single statements...
- if (prefix != null) { pushBackToken(); return prefix; }
- Expr tryBlock = parseBlock(true);
-
- tok = peekToken();
- ExprList list = new ExprList(curLine, TRY);
- if (tok == CATCH) {
- getToken();
- if (getToken() != LP) throw new ParserException("expected (");
- if (getToken() != NAME) throw new ParserException("expected name");
- Expr name = new Expr(curLine, NAME, string);
- if (getToken() != RP) throw new ParserException("expected )");
- list.add(new Expr(curLine, CATCH, name, parseBlock(false)));
- tok = peekToken();
- }
- if (tok == FINALLY) {
- getToken();
- list.add(new Expr(curLine, FINALLY, parseBlock(false)));
- }
-
- if (list.size() == 0) throw new ParserException("try without catch or finally");
- return new Expr(curLine, TRY, tryBlock, list);
- }
-
- default:
- pushBackToken();
- return prefix;
- }
+ private void _startExpr(JSFunction appendTo, int minPrecedence) throws IOException {
+ int tok = getToken();
+ JSFunction b = appendTo;
+
+ switch (tok) {
+ case -1: throw pe("expected expression");
+
+ // all of these simply push values onto the stack
+ case NUMBER: b.add(parserLine, LITERAL, number); break;
+ case STRING: b.add(parserLine, LITERAL, string); break;
+ case NULL: b.add(parserLine, LITERAL, null); break;
+ case TRUE: case FALSE: b.add(parserLine, LITERAL, JS.B(tok == TRUE)); break;
+
+ // (.foo) syntax
+ case DOT: {
+ consume(NAME);
+ b.add(parserLine, TOPSCOPE);
+ b.add(parserLine, LITERAL, "");
+ b.add(parserLine, GET);
+ b.add(parserLine, LITERAL, string);
+ b.add(parserLine, GET);
+ continueExpr(b, minPrecedence);
+ break;
+ }
+
+ case LB: {
+ b.add(parserLine, ARRAY, JS.ZERO); // push an array onto the stack
+ int size0 = b.size;
+ int i = 0;
+ if (peekToken() != RB)
+ while(true) { // iterate over the initialization values
+ int size = b.size;
+ b.add(parserLine, LITERAL, JS.N(i++)); // push the index in the array to place it into
+ if (peekToken() == COMMA || peekToken() == RB)
+ b.add(parserLine, LITERAL, null); // for stuff like [1,,2,]
+ else
+ 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;
+ consume(COMMA);
+ }
+ b.set(size0 - 1, JS.N(i)); // back at the ARRAY instruction, write the size of the array
+ consume(RB);
+ break;
+ }
+ case SUB: { // negative literal (like "3 * -1")
+ consume(NUMBER);
+ b.add(parserLine, LITERAL, JS.N(number.doubleValue() * -1));
+ break;
+ }
+ case LP: { // grouping (not calling)
+ startExpr(b, -1);
+ consume(RP);
+ break;
+ }
+ case INC: case DEC: { // prefix (not postfix)
+ startExpr(b, precedence[tok]);
+ int prev = b.size - 1;
+ if (b.get(prev) == GET && b.getArg(prev) != null)
+ b.set(prev, LITERAL, b.getArg(prev));
+ else if(b.get(prev) == GET)
+ b.pop();
+ else
+ throw pe("prefixed increment/decrement can only be performed on a valid assignment target");
+ b.add(parserLine, GET_PRESERVE, Boolean.TRUE);
+ b.add(parserLine, LITERAL, JS.N(1));
+ b.add(parserLine, tok == INC ? ADD : SUB, JS.N(2));
+ b.add(parserLine, PUT, null);
+ b.add(parserLine, SWAP, null);
+ b.add(parserLine, POP, null);
+ break;
+ }
+ case BANG: case BITNOT: case TYPEOF: {
+ startExpr(b, precedence[tok]);
+ b.add(parserLine, tok);
+ break;
+ }
+ case LC: { // object constructor
+ b.add(parserLine, OBJECT, null); // put an object on the stack
+ if (peekToken() != RC)
+ while(true) {
+ if (peekToken() != NAME && peekToken() != STRING)
+ throw pe("expected NAME or STRING");
+ getToken();
+ b.add(parserLine, LITERAL, string); // grab the key
+ consume(COLON);
+ 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;
+ consume(COMMA);
+ if (peekToken() == RC) break; // we permit {,,} -- I'm not sure if ECMA does
+ }
+ consume(RC);
+ break;
+ }
+ case NAME: {
+ b.add(parserLine, TOPSCOPE);
+ b.add(parserLine, LITERAL, string);
+ continueExprAfterAssignable(b,minPrecedence);
+ break;
+ }
+ case FUNCTION: {
+ consume(LP);
+ int numArgs = 0;
+ JSFunction b2 = new JSFunction(sourceName, parserLine, null);
+ b.add(parserLine, NEWFUNCTION, b2);
+
+ // function prelude; arguments array is already on the stack
+ b2.add(parserLine, TOPSCOPE);
+ b2.add(parserLine, SWAP);
+ b2.add(parserLine, DECLARE, "arguments"); // declare arguments (equivalent to 'var arguments;')
+ b2.add(parserLine, SWAP); // set this.arguments and leave the value on the stack
+ b2.add(parserLine, PUT);
+
+ while(peekToken() != RP) { // run through the list of argument names
+ numArgs++;
+ if (peekToken() == NAME) {
+ consume(NAME); // a named argument
+ String varName = string;
+
+ b2.add(parserLine, DUP); // dup the args array
+ b2.add(parserLine, GET, JS.N(numArgs - 1)); // retrieve it from the arguments array
+ b2.add(parserLine, TOPSCOPE);
+ b2.add(parserLine, SWAP);
+ b2.add(parserLine, DECLARE, varName); // declare the name
+ b2.add(parserLine, SWAP);
+ b2.add(parserLine, PUT);
+ b2.add(parserLine, POP); // pop the value
+ b2.add(parserLine, POP); // pop the scope
+ }
+ if (peekToken() == RP) break;
+ consume(COMMA);
+ }
+ consume(RP);
+
+ b2.numFormalArgs = numArgs;
+ b2.add(parserLine, POP); // pop off the arguments array
+ b2.add(parserLine, POP); // pop off TOPSCOPE
+
+ if(peekToken() != LC)
+ throw pe("JSFunctions must have a block surrounded by curly brackets");
+
+ parseBlock(b2, null); // the function body
+
+ b2.add(parserLine, LITERAL, null); // in case we "fall out the bottom", return NULL
+ b2.add(parserLine, RETURN);
+
+ break;
+ }
+ default: throw pe("expected expression, found " + codeToString[tok] + ", which cannot start an expression");
+ }
+
+ // attempt to continue the expression
+ continueExpr(b, minPrecedence);