package org.xwt.js;
// FIXME: line number accuracy
+// FIXME: scope management
import org.xwt.util.*;
import java.io.*;
/** for debugging */
public static void main(String[] s) throws Exception {
- CompiledFunction block = new CompiledFunction("stdin", 0, new InputStreamReader(System.in), null);
- if (block == null) return;
- System.out.println(block);
+ CompiledFunction block = new CompiledFunction("stdin", 0, new InputStreamReader(System.in), null);
+ if (block == null) return;
+ System.out.println(block);
}
static byte[] precedence = new byte[MAX_TOKEN + 1];
static boolean[] isRightAssociative = new boolean[MAX_TOKEN + 1];
static {
- isRightAssociative[ASSIGN] = true;
-
- precedence[ASSIGN] = 1;
- precedence[HOOK] = 2;
- precedence[COMMA] = 3;
- precedence[OR] = precedence[AND] = 4;
- precedence[GT] = precedence[GE] = 5;
- precedence[BITOR] = 6;
- precedence[BITXOR] = 7;
- precedence[BITAND] = 8;
- precedence[EQ] = precedence[NE] = 9;
- precedence[LT] = precedence[LE] = 10;
- precedence[SHEQ] = precedence[SHNE] = 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[LB] = 18;
- precedence[DOT] = 19;
+ isRightAssociative[ASSIGN] = true;
+
+ precedence[ASSIGN] = 1;
+ precedence[HOOK] = 2;
+ precedence[COMMA] = 3;
+ precedence[OR] = precedence[AND] = 4;
+ precedence[GT] = precedence[GE] = 5;
+ precedence[BITOR] = 6;
+ precedence[BITXOR] = 7;
+ precedence[BITAND] = 8;
+ precedence[EQ] = precedence[NE] = 9;
+ precedence[LT] = precedence[LE] = 10;
+ precedence[SHEQ] = precedence[SHNE] = 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[LB] = 18;
+ precedence[DOT] = 19;
}
/** gets a token and throws an exception if it is not <tt>code</tt> */
private void consume(int code) throws IOException {
- if (getToken() != code) throw new ParserException("expected " + codeToString[code] + ", got " + (op == -1 ? "EOF" : codeToString[op]));
+ if (getToken() != code) throw new ParserException("expected " + codeToString[code] + ", got " + (op == -1 ? "EOF" : codeToString[op]));
}
/**
* appended bytecodes MUST grow the stack by exactly one element.
*/
private void startExpr(CompiledFunction appendTo, int minPrecedence) throws IOException {
- int tok = getToken();
- CompiledFunction b = appendTo;
+ int tok = getToken();
+ CompiledFunction b = appendTo;
- switch (tok) {
- case -1: throw new ParserException("expected expression");
+ switch (tok) {
+ case -1: throw new ParserException("expected expression");
// all of these simply push values onto the stack
- case NUMBER: b.add(line, LITERAL, number); break;
- case STRING: b.add(line, LITERAL, string); break;
- case THIS: b.add(line, TOPSCOPE, null); break;
- case NULL: b.add(line, LITERAL, null); break;
- case TRUE: case FALSE: b.add(line, LITERAL, new Boolean(tok == TRUE)); break;
-
- case LB: {
- b.add(line, ARRAY, new Integer(0)); // 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();
- if (peekToken() == COMMA || peekToken() == RB)
- b.add(line, LITERAL, null); // for stuff like [1,,2,]
- else
- startExpr(b, -1); // push the value onto the stack
- b.add(line, LITERAL, new Integer(i++)); // push the index in the array to place it into
- b.add(line, PUT); // put it into the array
- b.add(line, POP); // discard the value remaining on the stack
- if (peekToken() == RB) break;
- consume(COMMA);
- }
- b.set(size0 - 1, new Integer(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(line, LITERAL, new Double(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]);
- b.set(b.size() - 1, tok, new Boolean(true)); // FIXME, ugly; need startAssignTarget
- break;
- }
- case BANG: case BITNOT: case TYPEOF: {
- startExpr(b, precedence[tok]);
- b.add(line, tok);
- break;
- }
- case LC: { // object constructor
- b.add(line, OBJECT, null); // put an object on the stack
- if (peekToken() != RC)
- while(true) {
- if (peekToken() != NAME && peekToken() != STRING)
- throw new ParserException("expected NAME or STRING");
- getToken();
- b.add(line, LITERAL, string); // grab the key
- consume(COLON);
- startExpr(b, -1); // grab the value
- b.add(line, PUT); // put the value into the object
- b.add(line, 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: { // FIXME; this is an lvalue
- String name = string;
- if (peekToken() == ASSIGN) {
- consume(ASSIGN);
- b.add(line, TOPSCOPE);
- b.add(line, LITERAL, name);
- startExpr(b, minPrecedence);
- b.add(line, PUT);
- b.add(line, SWAP);
- b.add(line, POP);
- } else {
- b.add(line, TOPSCOPE);
- b.add(line, LITERAL, name);
- b.add(line, GET);
- }
- break;
- }
- case FUNCTION: {
- consume(LP);
- int numArgs = 0;
- CompiledFunction b2 = new CompiledFunction(sourceName, line, null);
- b.add(line, NEWFUNCTION, b2);
-
- // function prelude; arguments array is already on the stack
- b2.add(line, TOPSCOPE); // push the scope onto the stack
- b2.add(line, SWAP); // swap 'this' and 'arguments'
-
- b2.add(line, LITERAL, "arguments"); // declare arguments (equivalent to 'var arguments;')
- b2.add(line, DECLARE);
-
- b2.add(line, LITERAL, "arguments"); // set this.arguments and leave the value on the stack
- b2.add(line, SWAP);
- b2.add(line, PUT);
- b2.add(line, SWAP);
- b2.add(line, POP);
-
- while(peekToken() != RP) { // run through the list of argument names
- if (peekToken() == NAME) {
- consume(NAME); // a named argument
-
- b2.add(line, LITERAL, string); // declare the name
- b2.add(line, DECLARE);
-
- b2.add(line, LITERAL, new Integer(numArgs)); // retrieve it from the arguments array
- b2.add(line, GET_PRESERVE);
- b2.add(line, SWAP);
- b2.add(line, POP);
-
- b2.add(line, TOPSCOPE); // put it to the current scope
- b2.add(line, SWAP);
- b2.add(line, LITERAL, string);
- b2.add(line, SWAP);
- b2.add(line, PUT);
-
- b2.add(line, POP); // clean the stack
- b2.add(line, POP);
- }
- if (peekToken() == RP) break;
- consume(COMMA);
- numArgs++;
- }
- consume(RP);
-
- b2.add(line, POP); // pop off the arguments array
-
- parseStatement(b2, null); // the function body
-
- b2.add(line, LITERAL, null); // in case we "fall out the bottom", return NULL
- b2.add(line, RETURN);
-
- break;
- }
- default: throw new ParserException("expected expression, found " + codeToString[tok] + ", which cannot start an expression");
- }
-
- // attempt to continue the expression
- continueExpr(b, minPrecedence);
+ case NUMBER: b.add(line, LITERAL, number); break;
+ case STRING: b.add(line, LITERAL, string); break;
+ case THIS: b.add(line, TOPSCOPE, null); break;
+ case NULL: b.add(line, LITERAL, null); break;
+ case TRUE: case FALSE: b.add(line, LITERAL, new Boolean(tok == TRUE)); break;
+
+ case LB: {
+ b.add(line, ARRAY, new Integer(0)); // 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();
+ if (peekToken() == COMMA || peekToken() == RB)
+ b.add(line, LITERAL, null); // for stuff like [1,,2,]
+ else
+ startExpr(b, -1); // push the value onto the stack
+ b.add(line, LITERAL, new Integer(i++)); // push the index in the array to place it into
+ b.add(line, PUT); // put it into the array
+ b.add(line, POP); // discard the value remaining on the stack
+ if (peekToken() == RB) break;
+ consume(COMMA);
+ }
+ b.set(size0 - 1, new Integer(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(line, LITERAL, new Double(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]);
+ b.set(b.size() - 1, tok, new Boolean(true)); // FIXME, ugly; need startAssignTarget
+ break;
+ }
+ case BANG: case BITNOT: case TYPEOF: {
+ startExpr(b, precedence[tok]);
+ b.add(line, tok);
+ break;
+ }
+ case LC: { // object constructor
+ b.add(line, OBJECT, null); // put an object on the stack
+ if (peekToken() != RC)
+ while(true) {
+ if (peekToken() != NAME && peekToken() != STRING)
+ throw new ParserException("expected NAME or STRING");
+ getToken();
+ b.add(line, LITERAL, string); // grab the key
+ consume(COLON);
+ startExpr(b, -1); // grab the value
+ b.add(line, PUT); // put the value into the object
+ b.add(line, 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: { // FIXME; this is an lvalue
+ String name = string;
+ if (peekToken() == ASSIGN) {
+ consume(ASSIGN);
+ b.add(line, TOPSCOPE);
+ b.add(line, LITERAL, name);
+ startExpr(b, minPrecedence);
+ b.add(line, PUT);
+ b.add(line, SWAP);
+ b.add(line, POP);
+ } else {
+ b.add(line, TOPSCOPE);
+ b.add(line, LITERAL, name);
+ b.add(line, GET);
+ }
+ break;
+ }
+ case FUNCTION: {
+ consume(LP);
+ int numArgs = 0;
+ CompiledFunction b2 = new CompiledFunction(sourceName, line, null);
+ b.add(line, NEWFUNCTION, b2);
+
+ // function prelude; arguments array is already on the stack
+ b2.add(line, TOPSCOPE); // push the scope onto the stack
+ b2.add(line, SWAP); // swap 'this' and 'arguments'
+
+ b2.add(line, LITERAL, "arguments"); // declare arguments (equivalent to 'var arguments;')
+ b2.add(line, DECLARE);
+
+ b2.add(line, LITERAL, "arguments"); // set this.arguments and leave the value on the stack
+ b2.add(line, SWAP);
+ b2.add(line, PUT);
+ b2.add(line, SWAP);
+ b2.add(line, POP);
+
+ while(peekToken() != RP) { // run through the list of argument names
+ if (peekToken() == NAME) {
+ consume(NAME); // a named argument
+
+ b2.add(line, LITERAL, string); // declare the name
+ b2.add(line, DECLARE);
+
+ b2.add(line, LITERAL, new Integer(numArgs)); // retrieve it from the arguments array
+ b2.add(line, GET_PRESERVE);
+ b2.add(line, SWAP);
+ b2.add(line, POP);
+
+ b2.add(line, TOPSCOPE); // put it to the current scope
+ b2.add(line, SWAP);
+ b2.add(line, LITERAL, string);
+ b2.add(line, SWAP);
+ b2.add(line, PUT);
+
+ b2.add(line, POP); // clean the stack
+ b2.add(line, POP);
+ }
+ if (peekToken() == RP) break;
+ consume(COMMA);
+ numArgs++;
+ }
+ consume(RP);
+
+ b2.add(line, POP); // pop off the arguments array
+
+ parseStatement(b2, null); // the function body
+
+ b2.add(line, LITERAL, null); // in case we "fall out the bottom", return NULL
+ b2.add(line, RETURN);
+
+ break;
+ }
+ default: throw new ParserException("expected expression, found " + codeToString[tok] + ", which cannot start an expression");
+ }
+
+ // attempt to continue the expression
+ continueExpr(b, minPrecedence);
}
/**
* depth.
*/
private void continueExpr(CompiledFunction b, int minPrecedence) throws IOException {
- if (b == null) throw new Error("got null b; this should never happen");
- int tok = getToken();
- if (tok == -1) return;
- if (minPrecedence != -1 && (precedence[tok] < minPrecedence || (precedence[tok] == minPrecedence && !isRightAssociative[tok]))) {
- pushBackToken();
- return;
- }
-
- switch (tok) {
+ if (b == null) throw new Error("got null b; this should never happen");
+ int tok = getToken();
+ if (tok == -1) return;
+ if (minPrecedence != -1 && (precedence[tok] < minPrecedence || (precedence[tok] == minPrecedence && !isRightAssociative[tok]))) {
+ pushBackToken();
+ return;
+ }
+
+ 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.set(b.size() - 1, b.GET_PRESERVE, new Boolean(true)); // FIXME should use AssignTarget
- startExpr(b, precedence[tok - 1]);
- b.add(line, tok - 1);
- b.add(line, PUT);
- b.add(line, SWAP);
- b.add(line, POP);
- break;
- }
- case INC: case DEC: { // postfix
- b.set(b.size() - 1, tok, new Boolean(false)); // FIXME use assignmenttarget
- break;
- }
- case LP: { // invocation (not grouping)
- int i = 0;
- while(peekToken() != RP) {
- i++;
- if (peekToken() != COMMA) {
- startExpr(b, -1);
- if (peekToken() == RP) break;
- }
- consume(COMMA);
- }
- consume(RP);
- b.add(line, CALL, new Integer(i));
- break;
- }
+ case ASSIGN_ADD: case ASSIGN_SUB: case ASSIGN_MUL: case ASSIGN_DIV: case ASSIGN_MOD: {
+ b.set(b.size() - 1, b.GET_PRESERVE, new Boolean(true)); // FIXME should use AssignTarget
+ startExpr(b, precedence[tok - 1]);
+ b.add(line, tok - 1);
+ b.add(line, PUT);
+ b.add(line, SWAP);
+ b.add(line, POP);
+ break;
+ }
+ case INC: case DEC: { // postfix
+ b.set(b.size() - 1, tok, new Boolean(false)); // FIXME use assignmenttarget
+ break;
+ }
+ case LP: { // invocation (not grouping)
+ int i = 0;
+ while(peekToken() != RP) {
+ i++;
+ if (peekToken() != COMMA) {
+ startExpr(b, -1);
+ if (peekToken() == RP) break;
+ }
+ consume(COMMA);
+ }
+ consume(RP);
+ b.add(line, CALL, new Integer(i));
+ break;
+ }
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: case SUB: {
- startExpr(b, precedence[tok]);
- b.add(line, tok);
- break;
- }
- case OR: case AND: {
- b.add(line, tok == AND ? b.JF : b.JT, new Integer(0)); // test to see if we can short-circuit
- int size = b.size();
- startExpr(b, precedence[tok]); // otherwise check the second value
- b.add(line, JMP, new Integer(2)); // leave the second value on the stack and jump to the end
- b.add(line, LITERAL, tok == AND ? new Boolean(false) : new Boolean(true)); // target of the short-circuit jump is here
- b.set(size - 1, new Integer(b.size() - size)); // write the target of the short-circuit jump
- break;
- }
- case DOT: { // FIXME, assigntarget
- consume(NAME);
- String target = string;
- if (peekToken() == ASSIGN) {
- consume(ASSIGN);
- b.add(line, LITERAL, target);
- startExpr(b, -1);
- b.add(line, PUT);
- b.add(line, SWAP);
- b.add(line, POP);
- } else {
- b.add(line, LITERAL, target);
- b.add(line, GET);
- }
- break;
- }
- case LB: { // subscripting (not array constructor)
- startExpr(b, -1);
- consume(RB);
- if (peekToken() == ASSIGN) { // FIXME: assigntarget
- consume(ASSIGN);
- startExpr(b, -1);
- b.add(line, PUT);
- b.add(line, SWAP);
- b.add(line, POP);
- } else {
- b.add(line, GET);
- }
- break;
- }
- case HOOK: {
- b.add(line, JF, new Integer(0)); // jump to the if-false expression
- int size = b.size();
- startExpr(b, -1); // write the if-true expression
- b.add(line, 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
- b.set(size - 1, new Integer(b.size() - size + 1)); // this is the end; jump to here
- break;
- }
- default: {
- pushBackToken();
- return;
- }
- }
-
- continueExpr(b, minPrecedence); // try to continue the expression
+ case RSH: case URSH: case ADD: case MUL: case DIV: case MOD:
+ case GT: case GE: case EQ: case NE: case LT: case LE: case SUB: {
+ startExpr(b, precedence[tok]);
+ b.add(line, tok);
+ break;
+ }
+ case OR: case AND: {
+ b.add(line, tok == AND ? b.JF : b.JT, new Integer(0)); // test to see if we can short-circuit
+ int size = b.size();
+ startExpr(b, precedence[tok]); // otherwise check the second value
+ b.add(line, JMP, new Integer(2)); // leave the second value on the stack and jump to the end
+ b.add(line, LITERAL, tok == AND ? new Boolean(false) : new Boolean(true)); // target of the short-circuit jump is here
+ b.set(size - 1, new Integer(b.size() - size)); // write the target of the short-circuit jump
+ break;
+ }
+ case DOT: { // FIXME, assigntarget
+ consume(NAME);
+ String target = string;
+ if (peekToken() == ASSIGN) {
+ consume(ASSIGN);
+ b.add(line, LITERAL, target);
+ startExpr(b, -1);
+ b.add(line, PUT);
+ b.add(line, SWAP);
+ b.add(line, POP);
+ } else {
+ b.add(line, LITERAL, target);
+ b.add(line, GET);
+ }
+ break;
+ }
+ case LB: { // subscripting (not array constructor)
+ startExpr(b, -1);
+ consume(RB);
+ if (peekToken() == ASSIGN) { // FIXME: assigntarget
+ consume(ASSIGN);
+ startExpr(b, -1);
+ b.add(line, PUT);
+ b.add(line, SWAP);
+ b.add(line, POP);
+ } else {
+ b.add(line, GET);
+ }
+ break;
+ }
+ case HOOK: {
+ b.add(line, JF, new Integer(0)); // jump to the if-false expression
+ int size = b.size();
+ startExpr(b, -1); // write the if-true expression
+ b.add(line, 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
+ b.set(size - 1, new Integer(b.size() - size + 1)); // this is the end; jump to here
+ break;
+ }
+ default: {
+ pushBackToken();
+ return;
+ }
+ }
+
+ continueExpr(b, minPrecedence); // try to continue the expression
}
/** Parse a block of statements which must be surrounded by LC..RC. */
void parseBlock(CompiledFunction b) throws IOException { parseBlock(b, null); }
void parseBlock(CompiledFunction b, String label) throws IOException {
- if (peekToken() == -1) return;
- else if (peekToken() != LC) parseStatement(b, null);
- else {
- consume(LC);
- while(peekToken() != RC && peekToken() != -1) parseStatement(b, null);
- consume(RC);
- }
+ if (peekToken() == -1) return;
+ else if (peekToken() != LC) parseStatement(b, null);
+ else {
+ consume(LC);
+ while(peekToken() != RC && peekToken() != -1) parseStatement(b, null);
+ consume(RC);
+ }
}
/** Parse a single statement, consuming the RC or SEMI which terminates it. */
void parseStatement(CompiledFunction b, String label) throws IOException {
- int tok = peekToken();
- if (tok == -1) return;
- switch(tok = getToken()) {
-
- case THROW: case ASSERT: case RETURN: {
- if (tok == RETURN && peekToken() == SEMI) b.add(line, LITERAL, null);
- else startExpr(b, -1);
- b.add(line, tok);
- consume(SEMI);
- break;
- }
-
- case BREAK: case CONTINUE: {
- if (peekToken() == NAME) consume(NAME);
- b.add(line, tok, string);
- consume(SEMI);
- break;
- }
-
- case VAR: {
- b.add(line, TOPSCOPE); // push the current scope
- while(true) {
- consume(NAME);
- String name = string;
- b.add(line, LITERAL, name); // push the name to be declared
- b.add(line, DECLARE); // declare it
- if (peekToken() == ASSIGN) { // if there is an '=' after the variable name
- b.add(line, LITERAL, name); // put the var name back on the stack
- consume(ASSIGN);
- startExpr(b, -1);
- b.add(line, PUT);
- b.add(line, POP);
- }
- if (peekToken() != COMMA) break;
- consume(COMMA);
- }
- b.add(line, POP);
- if ((mostRecentlyReadToken != RC || peekToken() == SEMI) && peekToken() != -1) consume(SEMI);
- break;
- }
-
- case IF: {
- consume(LP);
- startExpr(b, -1);
- consume(RP);
-
- b.add(line, JF, new Integer(0));
- int size = b.size();
- parseStatement(b, null);
-
- if (peekToken() == ELSE) {
- consume(ELSE);
- b.set(size - 1, new Integer(2 + b.size() - size));
- b.add(line, JMP, new Integer(0));
- size = b.size();
- parseStatement(b, null);
- }
- b.set(size - 1, new Integer(1 + b.size() - size));
- break;
- }
-
- case WHILE: {
- consume(LP);
- if (label != null) b.add(line, LABEL, label);
- b.add(line, LOOP);
- int size = b.size();
- b.add(line, POP);
- startExpr(b, -1);
- b.add(line, JT, new Integer(2));
- b.add(line, BREAK);
- consume(RP);
- parseStatement(b, null);
- b.add(line, CONTINUE); // if we fall out of the end, definately continue
- b.set(size - 1, new Integer(b.size() - size + 1)); // end of the loop
- break;
- }
-
- case SWITCH: {
- consume(LP);
- if (label != null) b.add(line, LABEL, label);
- b.add(line, LOOP);
- int size0 = b.size();
- startExpr(b, -1);
- consume(RP);
- consume(LC);
- while(true)
- if (peekToken() == CASE) {
- consume(CASE);
- b.add(line, DUP);
- startExpr(b, -1);
- consume(COLON);
- b.add(line, EQ);
- b.add(line, JF, new Integer(0));
- int size = b.size();
- while(peekToken() != CASE && peekToken() != DEFAULT && peekToken() != RC) {
- int size2 = b.size();
- parseStatement(b, null);
- if (size2 == b.size()) break;
- }
- b.set(size - 1, new Integer(1 + b.size() - size));
- } else if (peekToken() == DEFAULT) {
- consume(DEFAULT);
- consume(COLON);
- while(peekToken() != CASE && peekToken() != DEFAULT && peekToken() != RC) {
- int size2 = b.size();
- parseStatement(b, null);
- if (size2 == b.size()) break;
- }
- } else if (peekToken() == RC) {
- consume(RC);
- b.add(line, BREAK);
- break;
- } else {
- throw new ParserException("expected CASE, DEFAULT, or RC; got " + codeToString[peekToken()]);
- }
- b.add(line, BREAK);
- b.set(size0 - 1, new Integer(b.size() - size0 + 1)); // end of the loop
- break;
- }
-
- case DO: {
- if (label != null) b.add(line, LABEL, label);
- b.add(line, LOOP);
- int size = b.size();
- parseStatement(b, null);
- consume(WHILE);
- consume(LP);
- startExpr(b, -1);
- b.add(line, JT, new Integer(2));
- b.add(line, BREAK);
- b.add(line, CONTINUE);
- consume(RP);
- consume(SEMI);
- b.set(size - 1, new Integer(b.size() - size + 1)); // end of the loop
- break;
- }
-
- case TRY: {
- // We deliberately allow you to omit braces in catch{}/finally{} if they are single statements...
- b.add(line, TRY);
- int size = b.size();
- parseBlock(b, null);
- b.add(line, POP); // pop the TryMarker
- b.add(line, JMP); // jump forward to the end of the catch block
- int size2 = b.size();
- b.set(size - 1, new Integer(b.size() - size + 1));// the TRY argument points at the start of the CATCH block
-
- if (peekToken() == CATCH) {
- getToken();
- consume(LP);
- consume(NAME);
- consume(RP);
- // FIXME, we need an extra scope here
- b.add(line, TOPSCOPE); // the exception is on top of the stack; put it to the variable
- b.add(line, SWAP);
- b.add(line, LITERAL);
- b.add(line, SWAP);
- b.add(line, PUT);
- b.add(line, POP);
- b.add(line, POP);
- parseStatement(b, null);
- }
-
- b.set(size2 - 1, new Integer(b.size() - size2 + 1)); // jump here if no exception was thrown
-
- // FIXME: not implemented correctly
- if (peekToken() == FINALLY) {
- consume(FINALLY);
- parseStatement(b, null);
- }
- break;
- }
-
- case FOR: {
- consume(LP);
-
- tok = getToken();
- boolean hadVar = false;
- if (tok == VAR) { hadVar = true; tok = getToken(); }
- String varName = string;
- boolean forIn = peekToken() == IN;
- pushBackToken(tok, varName);
-
- if (forIn) {
- // FIXME: break needs to work in here
- consume(NAME);
- consume(IN);
- startExpr(b, -1);
- b.add(line, PUSHKEYS);
- b.add(line, LITERAL, "length");
- b.add(line, GET);
- consume(RP);
- CompiledFunction b2 = new CompiledFunction(sourceName, line, null);
-
- b.add(line, NEWSCOPE);
-
- b.add(line, LITERAL, new Integer(1));
- b.add(line, SUB);
- b.add(line, DUP);
- b.add(line, LITERAL, new Integer(0));
- b.add(line, LT);
- b.add(line, JT, new Integer(7));
- b.add(line, GET_PRESERVE);
- b.add(line, LITERAL, varName);
- b.add(line, LITERAL, varName);
- b.add(line, DECLARE);
- b.add(line, PUT);
- parseStatement(b, null);
-
- b.add(line, OLDSCOPE);
-
- break;
-
- } else {
- if (hadVar) pushBackToken(VAR, null);
- b.add(line, NEWSCOPE);
-
- parseStatement(b, null);
- CompiledFunction e2 = new CompiledFunction(sourceName, line, null);
- if (peekToken() != SEMI) {
- startExpr(e2, -1);
- } else {
- e2.add(line, b.LITERAL, Boolean.TRUE);
- }
- consume(SEMI);
- if (label != null) b.add(line, LABEL, label);
- b.add(line, LOOP);
- int size2 = b.size();
-
- b.add(line, JT, new Integer(0));
- int size = b.size();
- if (peekToken() != RP) {
- startExpr(b, -1);
- b.add(line, POP);
- }
- b.set(size - 1, new Integer(b.size() - size + 1));
- consume(RP);
-
- b.paste(e2);
- b.add(line, JT, new Integer(2));
- b.add(line, BREAK);
- parseStatement(b, null);
- b.add(line, CONTINUE);
- b.set(size2 - 1, new Integer(b.size() - size2 + 1)); // end of the loop
-
- b.add(line, OLDSCOPE);
- break;
- }
- }
-
- case NAME: {
- String possiblyTheLabel = string;
- if (peekToken() == COLON) {
- consume(COLON);
- label = possiblyTheLabel;
- parseStatement(b, label);
- break;
- } else {
- pushBackToken(NAME, possiblyTheLabel);
- startExpr(b, -1);
- b.add(line, POP);
- if ((mostRecentlyReadToken != RC || peekToken() == SEMI) && peekToken() != -1) consume(SEMI);
- break;
- }
- }
-
- case SEMI: return;
- case LC: {
- pushBackToken();
- parseBlock(b, label);
- break;
- }
-
- default: {
- pushBackToken();
- startExpr(b, -1);
- b.add(line, POP);
- if ((mostRecentlyReadToken != RC || peekToken() == SEMI) && peekToken() != -1) consume(SEMI);
- break;
- }
- }
+ int tok = peekToken();
+ if (tok == -1) return;
+ switch(tok = getToken()) {
+
+ case THROW: case ASSERT: case RETURN: {
+ if (tok == RETURN && peekToken() == SEMI)
+ b.add(line, LITERAL, null);
+ else
+ startExpr(b, -1);
+ b.add(line, tok);
+ consume(SEMI);
+ break;
+ }
+ case BREAK: case CONTINUE: {
+ if (peekToken() == NAME) consume(NAME);
+ b.add(line, tok, string);
+ consume(SEMI);
+ break;
+ }
+ case VAR: {
+ b.add(line, TOPSCOPE); // push the current scope
+ while(true) {
+ consume(NAME);
+ String name = string;
+ b.add(line, LITERAL, name); // push the name to be declared
+ b.add(line, DECLARE); // declare it
+ if (peekToken() == ASSIGN) { // if there is an '=' after the variable name
+ b.add(line, LITERAL, name); // put the var name back on the stack
+ consume(ASSIGN);
+ startExpr(b, -1);
+ b.add(line, PUT); // assign it
+ b.add(line, POP); // clean the stack
+ }
+ if (peekToken() != COMMA) break;
+ consume(COMMA);
+ }
+ b.add(line, POP); // pop off the topscope
+ if ((mostRecentlyReadToken != RC || peekToken() == SEMI) && peekToken() != -1) consume(SEMI);
+ break;
+ }
+ case IF: {
+ consume(LP);
+ startExpr(b, -1);
+ consume(RP);
+
+ b.add(line, JF, new Integer(0)); // if false, jump to the else-block
+ int size = b.size();
+ parseStatement(b, null);
+
+ if (peekToken() == ELSE) {
+ consume(ELSE);
+ b.add(line, JMP, new Integer(0)); // if we took the true-block, jump over the else-block
+ b.set(size - 1, new Integer(b.size() - size + 1));
+ size = b.size();
+ parseStatement(b, null);
+ }
+ b.set(size - 1, new Integer(b.size() - size + 1)); // regardless of which branch we took, b[size] needs to point here
+ break;
+ }
+ case WHILE: {
+ consume(LP);
+ if (label != null) b.add(line, LABEL, label);
+ b.add(line, LOOP);
+ int size = b.size();
+ b.add(line, POP); // discard the first-iteration indicator
+ startExpr(b, -1);
+ b.add(line, JT, new Integer(2)); // if the while() clause is true, jump over the BREAK
+ b.add(line, BREAK);
+ consume(RP);
+ parseStatement(b, null);
+ b.add(line, CONTINUE); // if we fall out of the end, definately continue
+ b.set(size - 1, new Integer(b.size() - size + 1)); // end of the loop
+ break;
+ }
+ case SWITCH: {
+ consume(LP);
+ if (label != null) b.add(line, LABEL, label);
+ b.add(line, LOOP);
+ int size0 = b.size();
+ startExpr(b, -1);
+ consume(RP);
+ consume(LC);
+ while(true)
+ if (peekToken() == CASE) { // we compile CASE statements like a bunch of if..else's
+ consume(CASE);
+ b.add(line, DUP); // duplicate the switch() value; we'll consume one copy
+ startExpr(b, -1);
+ consume(COLON);
+ b.add(line, EQ); // check if we should do this case-block
+ b.add(line, JF, new Integer(0)); // if not, jump to the next one
+ int size = b.size();
+ while(peekToken() != CASE && peekToken() != DEFAULT && peekToken() != RC) parseStatement(b, null);
+ b.set(size - 1, new Integer(1 + b.size() - size));
+ } else if (peekToken() == DEFAULT) {
+ consume(DEFAULT);
+ consume(COLON);
+ while(peekToken() != CASE && peekToken() != DEFAULT && peekToken() != RC) parseStatement(b, null);
+ } else if (peekToken() == RC) {
+ consume(RC);
+ b.add(line, BREAK); // break out of the loop if we 'fall through'
+ break;
+ } else {
+ throw new ParserException("expected CASE, DEFAULT, or RC; got " + codeToString[peekToken()]);
+ }
+ b.set(size0 - 1, new Integer(b.size() - size0 + 1)); // end of the loop
+ break;
+ }
+
+ case DO: {
+ if (label != null) b.add(line, LABEL, label);
+ b.add(line, LOOP);
+ int size = b.size();
+ parseStatement(b, null);
+ consume(WHILE);
+ consume(LP);
+ startExpr(b, -1);
+ b.add(line, JT, new Integer(2)); // check the while() clause; jump over the BREAK if true
+ b.add(line, BREAK);
+ b.add(line, CONTINUE);
+ consume(RP);
+ consume(SEMI);
+ b.set(size - 1, new Integer(b.size() - size + 1)); // end of the loop; write this location to the LOOP instruction
+ break;
+ }
+
+ case TRY: {
+ b.add(line, TRY);
+ int size = b.size();
+ parseStatement(b, null); // parse the expression to be TRYed
+ b.add(line, POP); // pop the TryMarker
+ b.add(line, JMP); // jump forward to the end of the catch block
+ int size2 = b.size();
+ b.set(size - 1, new Integer(b.size() - size + 1)); // the TRY argument points at the start of the CATCH block
+
+ if (peekToken() == CATCH) {
+ getToken();
+ consume(LP);
+ consume(NAME);
+ consume(RP);
+ // FIXME, we need an extra scope here
+ b.add(line, TOPSCOPE); // the exception is on top of the stack; put it to the chosen name
+ b.add(line, SWAP);
+ b.add(line, LITERAL);
+ b.add(line, SWAP);
+ b.add(line, PUT);
+ b.add(line, POP);
+ b.add(line, POP);
+ parseStatement(b, null);
+ }
+
+ // jump here if no exception was thrown
+ b.set(size2 - 1, new Integer(b.size() - size2 + 1));
+
+ // FIXME: not implemented correctly
+ if (peekToken() == FINALLY) {
+ consume(FINALLY);
+ parseStatement(b, null);
+ }
+ break;
+ }
+
+ case FOR: {
+ consume(LP);
+
+ tok = getToken();
+ boolean hadVar = false; // if it's a for..in, we ignore the VAR
+ if (tok == VAR) { hadVar = true; tok = getToken(); }
+ String varName = string;
+ boolean forIn = peekToken() == IN; // determine if this is a for..in loop or not
+ pushBackToken(tok, varName);
+
+ if (forIn) {
+ b.add(line, NEWSCOPE);
+ b.add(line, LITERAL, varName); // declare the new variable
+ b.add(line, DECLARE);
+
+ b.add(line, LOOP); // we actually only add this to ensure that BREAK works
+ b.add(line, POP); // discard the first-iteration indicator
+ int size = b.size();
+ consume(NAME);
+ consume(IN);
+ startExpr(b, -1);
+ b.add(line, PUSHKEYS); // push the keys as an array; check the length
+ b.add(line, LITERAL, "length");
+ b.add(line, GET);
+ consume(RP);
+
+ b.add(line, LITERAL, new Integer(1)); // decrement the length
+ b.add(line, SUB);
+ b.add(line, DUP);
+ b.add(line, LITERAL, new Integer(0)); // see if we've exhausted all the elements
+ b.add(line, LT);
+ b.add(line, JF, new Integer(2));
+ b.add(line, BREAK); // if we have, then BREAK
+ b.add(line, GET_PRESERVE); // get the key out of the keys array
+ b.add(line, LITERAL, varName);
+ b.add(line, PUT); // write it to this[varName]
+ parseStatement(b, null); // do some stuff
+ b.add(line, CONTINUE); // continue if we fall out the bottom
+
+ b.set(size - 1, new Integer(b.size() - size + 1)); // BREAK to here
+ b.add(line, OLDSCOPE); // restore the scope
+
+ } else {
+ if (hadVar) pushBackToken(VAR, null); // yeah, this actually matters
+ b.add(line, NEWSCOPE); // grab a fresh scope
+
+ parseStatement(b, null); // initializer
+ CompiledFunction e2 = // we need to put the incrementor before the test
+ new CompiledFunction(sourceName, line, null); // so we save the test here
+ if (peekToken() != SEMI)
+ startExpr(e2, -1);
+ else
+ e2.add(line, b.LITERAL, Boolean.TRUE); // handle the for(foo;;foo) case
+ consume(SEMI);
+ if (label != null) b.add(line, LABEL, label);
+ b.add(line, LOOP);
+ int size2 = b.size();
+
+ b.add(line, JT, new Integer(0)); // if we're on the first iteration, jump over the incrementor
+ int size = b.size();
+ if (peekToken() != RP) { // do the increment thing
+ startExpr(b, -1);
+ b.add(line, POP);
+ }
+ b.set(size - 1, new Integer(b.size() - size + 1));
+ consume(RP);
+
+ b.paste(e2); // ok, *now* test if we're done yet
+ b.add(line, JT, new Integer(2)); // break out if we don't meet the test
+ b.add(line, BREAK);
+ parseStatement(b, null);
+ b.add(line, CONTINUE); // if we fall out the bottom, CONTINUE
+ b.set(size2 - 1, new Integer(b.size() - size2 + 1)); // end of the loop
+
+ b.add(line, OLDSCOPE); // get our scope back
+ }
+ break;
+ }
+
+ case NAME: { // either a label or an identifier; this is the one place we're not LL(1)
+ String possiblyTheLabel = string;
+ if (peekToken() == COLON) { // label
+ consume(COLON);
+ parseStatement(b, possiblyTheLabel);
+ break;
+ } else { // expression
+ pushBackToken(NAME, possiblyTheLabel);
+ startExpr(b, -1);
+ b.add(line, POP);
+ if ((mostRecentlyReadToken != RC || peekToken() == SEMI) && peekToken() != -1) consume(SEMI);
+ break;
+ }
+ }
+
+ case SEMI: return; // yep, the null statement is valid
+
+ case LC: { // blocks are statements too
+ pushBackToken();
+ parseBlock(b, label);
+ break;
+ }
+
+ default: { // hope that it's an expression
+ pushBackToken();
+ startExpr(b, -1);
+ b.add(line, POP);
+ if ((mostRecentlyReadToken != RC || peekToken() == SEMI) && peekToken() != -1) consume(SEMI);
+ break;
+ }
+ }
}
projects / org.ibex.core.git / commitdiff