import org.xwt.util.*;
import java.io.*;
+// FEATURE intern Integers/Numbers
+
/**
- * Parses a stream of lexed tokens into a tree of CompiledFunctionImpl's.
+ * Parses a stream of lexed tokens into a tree of JSFunction's.
*
* There are three kinds of things we parse: blocks, statements, and
* expressions.
/** for debugging */
public static void main(String[] s) throws Exception {
- CompiledFunctionImpl block = new JS.CompiledFunction("stdin", 0, new InputStreamReader(System.in), null);
+ JSFunction block = new JSFunction("stdin", 0, new InputStreamReader(System.in), null);
if (block == null) return;
System.out.println(block);
}
* bytecodes for that expression to <tt>appendTo</tt>; the
* appended bytecodes MUST grow the stack by exactly one element.
*/
- private void startExpr(CompiledFunctionImpl appendTo, int minPrecedence) throws IOException {
+ private void startExpr(JSFunction appendTo, int minPrecedence) throws IOException {
int saveParserLine = parserLine;
_startExpr(appendTo, minPrecedence);
parserLine = saveParserLine;
}
- private void _startExpr(CompiledFunctionImpl appendTo, int minPrecedence) throws IOException {
+ private void _startExpr(JSFunction appendTo, int minPrecedence) throws IOException {
int tok = getToken();
- CompiledFunctionImpl b = appendTo;
+ 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 THIS: b.add(parserLine, TOPSCOPE, null); break;
case NULL: b.add(parserLine, LITERAL, null); break;
case TRUE: case FALSE: b.add(parserLine, LITERAL, new Boolean(tok == TRUE)); break;
case LB: {
b.add(parserLine, ARRAY, new Integer(0)); // push an array onto the stack
- int size0 = b.size();
+ int size0 = b.size;
int i = 0;
if (peekToken() != RB)
while(true) { // iterate over the initialization values
- int size = b.size();
+ int size = b.size;
b.add(parserLine, LITERAL, new Integer(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,]
}
case INC: case DEC: { // prefix (not postfix)
startExpr(b, precedence[tok]);
- int prev = b.size() - 1;
+ 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, tok, Boolean.TRUE);
+ b.add(parserLine, GET_PRESERVE, Boolean.TRUE);
+ b.add(parserLine, LITERAL, new Integer(1));
+ b.add(parserLine, tok == INC ? ADD : SUB, null);
+ b.add(parserLine, PUT, null);
+ b.add(parserLine, SWAP, null);
+ b.add(parserLine, POP, null);
break;
}
case BANG: case BITNOT: case TYPEOF: {
case FUNCTION: {
consume(LP);
int numArgs = 0;
- CompiledFunctionImpl b2 = new JS.CompiledFunction(sourceName, parserLine, null, null);
+ JSFunction b2 = new JSFunction(sourceName, parserLine, null, null);
b.add(parserLine, NEWFUNCTION, b2);
// function prelude; arguments array is already 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, new Integer(numArgs)); // retrieve it from the arguments array
+ b2.add(parserLine, GET, new Integer(numArgs - 1)); // retrieve it from the arguments array
b2.add(parserLine, TOPSCOPE);
b2.add(parserLine, SWAP);
b2.add(parserLine, DECLARE, varName); // declare the name
}
if (peekToken() == RP) break;
consume(COMMA);
- numArgs++;
}
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("Functions must have a block surrounded by curly brackets");
+ throw pe("JSFunctions must have a block surrounded by curly brackets");
parseBlock(b2, null); // the function body
- if(b2.get(b2.size()-1) != RETURN) {
- b2.add(parserLine, LITERAL, null); // in case we "fall out the bottom", return NULL
- b2.add(parserLine, RETURN);
- }
+ b2.add(parserLine, LITERAL, null); // in case we "fall out the bottom", return NULL
+ b2.add(parserLine, RETURN);
break;
}
* expression that modifies the assignable. This method always
* decreases the stack depth by exactly one element.
*/
- private void continueExprAfterAssignable(CompiledFunctionImpl b,int minPrecedence) throws IOException {
+ private void continueExprAfterAssignable(JSFunction b,int minPrecedence) throws IOException {
int saveParserLine = parserLine;
_continueExprAfterAssignable(b,minPrecedence);
parserLine = saveParserLine;
}
- private void _continueExprAfterAssignable(CompiledFunctionImpl b,int minPrecedence) throws IOException {
+ private void _continueExprAfterAssignable(JSFunction 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])))
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: {
+ case ASSIGN_MUL: case ASSIGN_DIV: case ASSIGN_MOD: case ASSIGN_ADD: case ASSIGN_SUB: {
b.add(parserLine, GET_PRESERVE);
startExpr(b, precedence[tok]);
+ int size = b.size;
+ if (tok == ASSIGN_ADD || tok == ASSIGN_SUB) {
+ b.add(parserLine, 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);
b.add(parserLine, SWAP);
b.add(parserLine, POP);
+ if (tok == ASSIGN_ADD || tok == ASSIGN_SUB) b.set(size, tok, new Integer(b.size - size));
break;
}
case INC: case DEC: { // postfix
- b.add(parserLine, tok, Boolean.FALSE);
+ b.add(parserLine, GET_PRESERVE, Boolean.TRUE);
+ b.add(parserLine, LITERAL, new Integer(1));
+ b.add(parserLine, tok == INC ? ADD : SUB, null);
+ b.add(parserLine, PUT, null);
+ b.add(parserLine, SWAP, null);
+ b.add(parserLine, POP, null);
+ b.add(parserLine, LITERAL, new Integer(1));
+ b.add(parserLine, tok == INC ? SUB : ADD, null); // undo what we just did, since this is postfix
break;
}
case ASSIGN: {
break;
}
case LP: {
- int n = parseArgs(b);
+ int n = parseArgs(b, false);
+
+ // if the object supports GETCALL, we use this, and jump over the following two instructions
b.add(parserLine,CALLMETHOD,new Integer(n));
+ b.add(parserLine,GET);
+ b.add(parserLine,CALL,new Integer(n));
break;
}
default: {
pushBackToken();
- if(b.get(b.size()-1) == LITERAL && b.getArg(b.size()-1) != null)
- b.set(b.size()-1,GET,b.getArg(b.size()-1));
+ if(b.get(b.size-1) == LITERAL && b.getArg(b.size-1) != null)
+ b.set(b.size-1,GET,b.getArg(b.size-1));
else
b.add(parserLine, GET);
return;
* If any bytecodes are appended, they will not alter the stack
* depth.
*/
- private void continueExpr(CompiledFunctionImpl b, int minPrecedence) throws IOException {
+ private void continueExpr(JSFunction b, int minPrecedence) throws IOException {
int saveParserLine = parserLine;
_continueExpr(b, minPrecedence);
parserLine = saveParserLine;
}
- private void _continueExpr(CompiledFunctionImpl b, int minPrecedence) throws IOException {
+ private void _continueExpr(JSFunction 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;
switch (tok) {
case LP: { // invocation (not grouping)
- int n = parseArgs(b);
+ int n = parseArgs(b, true);
b.add(parserLine, CALL, new Integer(n));
break;
}
}
case OR: case AND: {
b.add(parserLine, tok == AND ? b.JF : b.JT, new Integer(0)); // test to see if we can short-circuit
- int size = b.size();
+ int size = b.size;
startExpr(b, precedence[tok]); // otherwise check the second value
b.add(parserLine, JMP, new Integer(2)); // leave the second value on the stack and jump to the end
b.add(parserLine, 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
+ b.set(size - 1, new Integer(b.size - size)); // write the target of the short-circuit jump
break;
}
case DOT: {
- consume(NAME);
+ // support foo..bar syntax for foo[""].bar
+ if (peekToken() == DOT) {
+ string = "";
+ } else {
+ consume(NAME);
+ }
b.add(parserLine, LITERAL, string);
continueExprAfterAssignable(b,minPrecedence);
break;
}
case HOOK: {
b.add(parserLine, JF, new Integer(0)); // jump to the if-false expression
- int size = b.size();
+ int size = b.size;
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
+ 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();
+ size = b.size;
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
+ b.set(size - 1, new Integer(b.size - size + 1)); // this is the end; jump to here
break;
}
case COMMA: {
}
// parse a set of comma separated function arguments, assume LP has already been consumed
- private int parseArgs(CompiledFunctionImpl b) throws IOException {
+ // if swap is true, (because the function is already on the stack) we will SWAP after each argument to keep it on top
+ private int parseArgs(JSFunction b, boolean swap) throws IOException {
int i = 0;
while(peekToken() != RP) {
i++;
if (peekToken() != COMMA) {
startExpr(b, NO_COMMA);
+ if (swap) b.add(parserLine, SWAP);
if (peekToken() == RP) break;
}
consume(COMMA);
}
/** Parse a block of statements which must be surrounded by LC..RC. */
- void parseBlock(CompiledFunctionImpl b) throws IOException { parseBlock(b, null); }
- void parseBlock(CompiledFunctionImpl b, String label) throws IOException {
+ void parseBlock(JSFunction b) throws IOException { parseBlock(b, null); }
+ void parseBlock(JSFunction b, String label) throws IOException {
int saveParserLine = parserLine;
_parseBlock(b, label);
parserLine = saveParserLine;
}
- void _parseBlock(CompiledFunctionImpl b, String label) throws IOException {
+ void _parseBlock(JSFunction b, String label) throws IOException {
if (peekToken() == -1) return;
else if (peekToken() != LC) parseStatement(b, null);
else {
}
/** Parse a single statement, consuming the RC or SEMI which terminates it. */
- void parseStatement(CompiledFunctionImpl b, String label) throws IOException {
+ void parseStatement(JSFunction b, String label) throws IOException {
int saveParserLine = parserLine;
_parseStatement(b, label);
parserLine = saveParserLine;
}
- void _parseStatement(CompiledFunctionImpl b, String label) throws IOException {
+ void _parseStatement(JSFunction b, String label) throws IOException {
int tok = peekToken();
if (tok == -1) return;
switch(tok = getToken()) {
consume(RP);
b.add(parserLine, JF, new Integer(0)); // if false, jump to the else-block
- int size = b.size();
+ int size = b.size;
parseStatement(b, null);
if (peekToken() == ELSE) {
consume(ELSE);
b.add(parserLine, 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();
+ 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
+ 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(parserLine, LABEL, label);
b.add(parserLine, LOOP);
- int size = b.size();
+ int size = b.size;
b.add(parserLine, POP); // discard the first-iteration indicator
startExpr(b, -1);
b.add(parserLine, JT, new Integer(2)); // if the while() clause is true, jump over the BREAK
consume(RP);
parseStatement(b, null);
b.add(parserLine, CONTINUE); // if we fall out of the end, definately continue
- b.set(size - 1, new Integer(b.size() - size + 1)); // end of the loop
+ b.set(size - 1, new Integer(b.size - size + 1)); // end of the loop
break;
}
case SWITCH: {
consume(LP);
if (label != null) b.add(parserLine, LABEL, label);
b.add(parserLine, LOOP);
- int size0 = b.size();
+ int size0 = b.size;
startExpr(b, -1);
consume(RP);
consume(LC);
consume(COLON);
b.add(parserLine, EQ); // check if we should do this case-block
b.add(parserLine, JF, new Integer(0)); // if not, jump to the next one
- int size = b.size();
+ int size = b.size;
while(peekToken() != CASE && peekToken() != DEFAULT && peekToken() != RC) parseStatement(b, null);
- b.set(size - 1, new Integer(1 + b.size() - size));
+ b.set(size - 1, new Integer(1 + b.size - size));
} else if (peekToken() == DEFAULT) {
consume(DEFAULT);
consume(COLON);
} else {
throw pe("expected CASE, DEFAULT, or RC; got " + codeToString[peekToken()]);
}
- b.set(size0 - 1, new Integer(b.size() - size0 + 1)); // end of the loop
+ b.set(size0 - 1, new Integer(b.size - size0 + 1)); // end of the loop
break;
}
case DO: {
if (label != null) b.add(parserLine, LABEL, label);
b.add(parserLine, LOOP);
- int size = b.size();
+ int size = b.size;
parseStatement(b, null);
consume(WHILE);
consume(LP);
b.add(parserLine, 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
+ 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(parserLine, TRY); // try bytecode causes a TryMarker to be pushed
- int tryInsn = b.size() - 1;
+ int tryInsn = b.size - 1;
// parse the expression to be TRYed
parseStatement(b, null);
// pop the try marker. this is pushed when the TRY bytecode is executed
b.add(parserLine, POP);
// jump forward to the end of the catch block, start of the finally block
b.add(parserLine, JMP);
- int successJMPInsn = b.size() - 1;
+ int successJMPInsn = b.size - 1;
if (peekToken() != CATCH && peekToken() != FINALLY)
throw pe("try without catch or finally");
int catchJMPDistance = -1;
if (peekToken() == CATCH) {
- catchJMPDistance = b.size() - tryInsn;
+ catchJMPDistance = b.size - tryInsn;
String exceptionVar;
getToken();
consume(LP);
}
// jump here if no exception was thrown
- b.set(successJMPInsn, new Integer(b.size() - successJMPInsn));
+ b.set(successJMPInsn, new Integer(b.size - successJMPInsn));
int finallyJMPDistance = -1;
if (peekToken() == FINALLY) {
b.add(parserLine, LITERAL, null); // null FinallyData
- finallyJMPDistance = b.size() - tryInsn;
+ finallyJMPDistance = b.size - tryInsn;
consume(FINALLY);
parseStatement(b, null);
b.add(parserLine,FINALLY_DONE);
b.add(parserLine, LOOP); // we actually only add this to ensure that BREAK works
b.add(parserLine, POP); // discard the first-iteration indicator
- int size = b.size();
+ int size = b.size;
consume(NAME);
consume(IN);
startExpr(b, -1);
parseStatement(b, null); // do some stuff
b.add(parserLine, CONTINUE); // continue if we fall out the bottom
- b.set(size - 1, new Integer(b.size() - size + 1)); // BREAK to here
+ b.set(size - 1, new Integer(b.size - size + 1)); // BREAK to here
b.add(parserLine, OLDSCOPE); // restore the scope
} else {
b.add(parserLine, NEWSCOPE); // grab a fresh scope
parseStatement(b, null); // initializer
- CompiledFunctionImpl e2 = // we need to put the incrementor before the test
- new JS.CompiledFunction(sourceName, parserLine, null, null); // so we save the test here
+ JSFunction e2 = // we need to put the incrementor before the test
+ new JSFunction(sourceName, parserLine, null, null); // so we save the test here
if (peekToken() != SEMI)
startExpr(e2, -1);
else
consume(SEMI);
if (label != null) b.add(parserLine, LABEL, label);
b.add(parserLine, LOOP);
- int size2 = b.size();
+ int size2 = b.size;
b.add(parserLine, JT, new Integer(0)); // if we're on the first iteration, jump over the incrementor
- int size = b.size();
+ int size = b.size;
if (peekToken() != RP) { // do the increment thing
startExpr(b, -1);
b.add(parserLine, POP);
}
- b.set(size - 1, new Integer(b.size() - size + 1));
+ 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(parserLine, BREAK);
parseStatement(b, null);
b.add(parserLine, CONTINUE); // if we fall out the bottom, CONTINUE
- b.set(size2 - 1, new Integer(b.size() - size2 + 1)); // end of the loop
+ b.set(size2 - 1, new Integer(b.size - size2 + 1)); // end of the loop
b.add(parserLine, OLDSCOPE); // get our scope back
}