import org.xwt.util.*;
import java.io.*;
-/** parses a stream of lexed tokens into ForthBlock's */
-public class Parser extends Lexer implements OpCodes {
+/** Parses a stream of lexed tokens into a tree of CompiledFunction's */
+class Parser extends Lexer implements ByteCodes {
+
// Constructors //////////////////////////////////////////////////////
- public Parser(Reader r, String sourceName, int line) throws IOException {
- super(r);
- this.sourceName = sourceName;
- this.line = line;
- }
+ public Parser(Reader r, String sourceName, int line) throws IOException { super(r, sourceName, line); }
/** for debugging */
public static void main(String[] s) throws Exception {
- Parser p = new Parser(new InputStreamReader(System.in), "stdin", 0);
- while(true) {
- ForthBlock block = new ForthBlock(0, "stdin");
- p.parseStatement(false, block);
- if (block == null) return;
- System.out.println(block);
- if (p.peekToken() == -1) return;
- }
+ CompiledFunction block = new CompiledFunction("stdin", 0, new InputStreamReader(System.in), null);
+ if (block == null) return;
+ System.out.println(block);
}
precedence[LSH] = precedence[RSH] = precedence[URSH] = 12;
precedence[ADD] = precedence[SUB] = 13;
precedence[MUL] = precedence[DIV] = precedence[MOD] = 14;
- precedence[BITNOT] = precedence[INSTANCEOF] = 15;
+ precedence[BITNOT] = 15;
precedence[INC] = precedence[DEC] = 16;
precedence[LP] = 17;
precedence[LB] = 18;
/** gets a token and throws an exception if it is not <tt>code</tt> */
public void consume(int code) throws IOException {
if (getToken() != code)
- throw new ParserException("expected " + codeToString[code] + ", got " + (op == -1 ? "EOL" : codeToString[op]));
+ throw new ParserException("expected " + codeToString[code] + ", got " + (op == -1 ? "EOF" : codeToString[op]));
}
- /** append the largest expression beginning with prefix containing no operators of precedence below <tt>minPrecedence</tt> */
- public ForthBlock startExpr() throws IOException { return startExpr(-1); }
- public ForthBlock startExpr(int minPrecedence) throws IOException { return startExpr(minPrecedence, new ForthBlock(line, sourceName)); }
- public ForthBlock startExpr(int minPrecedence, ForthBlock appendTo) throws IOException {
-
+ /** append the largest possible expression containing no operators of precedence below <tt>minPrecedence</tt> */
+ public void startExpr(int minPrecedence, CompiledFunction appendTo) throws IOException {
int tok = getToken();
- int curLine = line;
- if (tok == -1) return null;
- if (minPrecedence > 0 && precedence[tok] != 0)
- if (precedence[tok] < minPrecedence || (precedence[tok] == minPrecedence && !isRightAssociative[tok]))
- { pushBackToken(); return null; }
-
- ForthBlock b = appendTo;
+ CompiledFunction b = appendTo;
switch (tok) {
- case NUMBER: return continueExpr(b.add(ForthBlock.LITERAL, number), minPrecedence);
- case STRING: return continueExpr(b.add(ForthBlock.LITERAL, string), minPrecedence);
- case THIS: return continueExpr(b.add(THIS, null), minPrecedence);
- case NULL: return continueExpr(b.add(ForthBlock.LITERAL, null), minPrecedence);
- case TRUE: case FALSE: return continueExpr(b.add(ForthBlock.LITERAL, new Boolean(tok == TRUE)), minPrecedence);
+ case -1: return;
+ case NUMBER: continueExpr(b.add(line, CompiledFunction.LITERAL, number), minPrecedence); return;
+ case STRING: continueExpr(b.add(line, CompiledFunction.LITERAL, string), minPrecedence); return;
+ case THIS: continueExpr(b.add(line, TOPSCOPE, null), minPrecedence); return;
+ case NULL: continueExpr(b.add(line, CompiledFunction.LITERAL, null), minPrecedence); return;
+ case TRUE: case FALSE: continueExpr(b.add(line, CompiledFunction.LITERAL, new Boolean(tok == TRUE)), minPrecedence); return;
case LB: {
- b.add(b.ARRAY, new Integer(0));
+ b.add(line, ARRAY, new Integer(0));
int i = 0;
while(true) {
- ForthBlock e = startExpr();
- if (e == null && peekToken() == RB) { consume(RB); return continueExpr(b, minPrecedence); }
- 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);
- b.add(b.POP);
- if (peekToken() == RB) { consume(RB); return continueExpr(b, minPrecedence); }
+ int size = b.size();
+ startExpr(-1, b);
+ if (size == b.size())
+ if (peekToken() == RB) { consume(RB); continueExpr(b, minPrecedence); return; }
+ b.add(line, LITERAL, new Integer(i++));
+ if (size == b.size()) b.add(line, LITERAL, null);
+ b.add(line, PUT);
+ b.add(line, POP);
+ if (peekToken() == RB) { consume(RB); continueExpr(b, minPrecedence); return; }
consume(COMMA);
}
}
case SUB: {
consume(NUMBER);
- return continueExpr(b.add(ForthBlock.LITERAL, new Double(number.doubleValue() * -1)), minPrecedence);
+ b.add(line, CompiledFunction.LITERAL, new Double(number.doubleValue() * -1));
+ continueExpr(b, minPrecedence);
+ return;
}
case LP: {
- b.add(EXPR, startExpr());
+ startExpr(-1, b);
consume(RP);
- return continueExpr(b, minPrecedence);
+ continueExpr(b, minPrecedence);
+ return;
}
case INC: case DEC: {
// prefix
- ForthBlock subexp = startExpr(precedence[tok]);
- subexp.set(subexp.size() - 1, tok, new Boolean(true));
- b.add(b.EXPR, subexp);
- return continueExpr(b, minPrecedence);
+ startExpr(precedence[tok], b);
+ b.set(b.size() - 1, tok, new Boolean(true));
+ continueExpr(b, minPrecedence);
+ return;
}
- case BANG: case BITNOT: case INSTANCEOF: case TYPEOF: {
- b.add(b.EXPR, startExpr(precedence[tok]));
- b.add(tok);
- return continueExpr(b, minPrecedence);
+ case BANG: case BITNOT: case TYPEOF: {
+ startExpr(precedence[tok], b);
+ b.add(line, tok);
+ continueExpr(b, minPrecedence);
+ return;
}
case LC: {
- b.add(b.OBJECT, null);
- if (peekToken() == RC) { consume(RC); return continueExpr(b, minPrecedence); }
- while(true) {
+ b.add(line, OBJECT, null);
+ if (peekToken() != RC) while(true) {
if (peekToken() != NAME && peekToken() != STRING) throw new Error("expected NAME or STRING");
getToken();
- b.add(b.LITERAL, string);
+ b.add(line, LITERAL, string);
consume(COLON);
- b.add(b.EXPR, startExpr());
- b.add(b.PUT);
- b.add(b.POP);
- if (peekToken() == RC) { consume(RC); return continueExpr(b, minPrecedence); }
+ startExpr(-1, b);
+ b.add(line, PUT);
+ b.add(line, POP);
+ if (peekToken() == RC) break;
consume(COMMA);
- if (peekToken() == RC) { consume(RC); return continueExpr(b, minPrecedence); }
+ if (peekToken() == RC) break;
}
+ consume(RC);
+ continueExpr(b, minPrecedence);
+ return;
}
case NAME: {
String name = string;
if (peekToken() == ASSIGN) {
consume(ASSIGN);
- b.add(THIS);
- b.add(ForthBlock.LITERAL, name);
- b.add(ForthBlock.EXPR, startExpr(minPrecedence));
- b.add(ForthBlock.PUT);
- b.add(ForthBlock.SWAP);
- b.add(ForthBlock.POP);
+ b.add(line, TOPSCOPE);
+ b.add(line, CompiledFunction.LITERAL, name);
+ startExpr(minPrecedence, b);
+ b.add(line, CompiledFunction.PUT);
+ b.add(line, CompiledFunction.SWAP);
+ b.add(line, CompiledFunction.POP);
} else {
- b.add(THIS);
- b.add(ForthBlock.LITERAL, name);
- b.add(ForthBlock.GET);
+ b.add(line, TOPSCOPE);
+ b.add(line, CompiledFunction.LITERAL, name);
+ b.add(line, CompiledFunction.GET);
}
- return continueExpr(b, minPrecedence);
+ continueExpr(b, minPrecedence);
+ return;
}
- case Tokens.FUNCTION: {
+ case FUNCTION: {
consume(LP);
int numArgs = 0;
- ForthBlock b2 = new ForthBlock(curLine, sourceName);
- b2.add(THIS);
- b2.add(b.SWAP);
- b2.add(b.LITERAL, "arguments");
- b2.add(b.LITERAL, "arguments");
- b2.add(b.DECLARE);
- b2.add(b.SWAP);
- b2.add(b.PUT);
- b2.add(b.SWAP);
- b2.add(b.POP);
+ CompiledFunction b2 = new CompiledFunction(sourceName, line, null);
+ b2.add(line, TOPSCOPE);
+ b2.add(line, SWAP);
+ b2.add(line, LITERAL, "arguments");
+ b2.add(line, LITERAL, "arguments");
+ b2.add(line, DECLARE);
+ b2.add(line, SWAP);
+ b2.add(line, PUT);
+ b2.add(line, SWAP);
+ b2.add(line, POP);
if (peekToken() == RP) consume(RP);
else while(true) {
if (peekToken() == COMMA) {
- // FIXME: pop an item off the stack here?
consume(COMMA);
+
} else {
consume(NAME);
// declare the name
- b2.add(b.LITERAL, string);
- b2.add(b.DECLARE);
+ b2.add(line, LITERAL, string);
+ b2.add(line, DECLARE);
// retrieve it from the arguments array
- b2.add(b.LITERAL, new Integer(numArgs));
- b2.add(b.GET_PRESERVE);
- b2.add(b.SWAP);
- b2.add(b.POP);
+ b2.add(line, LITERAL, new Integer(numArgs));
+ b2.add(line, GET_PRESERVE);
+ b2.add(line, SWAP);
+ b2.add(line, POP);
// put it to the current scope
- b2.add(THIS);
- b2.add(b.SWAP);
- b2.add(b.LITERAL, string);
- b2.add(b.SWAP);
- b2.add(b.PUT);
+ b2.add(line, TOPSCOPE);
+ b2.add(line, SWAP);
+ b2.add(line, LITERAL, string);
+ b2.add(line, SWAP);
+ b2.add(line, PUT);
// clean the stack
- b2.add(b.POP);
- b2.add(b.POP);
+ b2.add(line, POP);
+ b2.add(line, POP);
if (peekToken() == RP) { consume(RP); break; }
consume(COMMA);
numArgs++;
}
// pop off the arguments array
- b2.add(b.POP);
+ b2.add(line, POP);
parseStatement(true, b2);
- b2.add(b.LITERAL, null);
- b2.add(RETURN);
- return continueExpr(b.add(OpCodes.FUNCTION, b2), minPrecedence);
+ b2.add(line, LITERAL, null);
+ b2.add(line, RETURN);
+ continueExpr(b.add(line, NEWFUNCTION, b2), minPrecedence);
+ return;
}
- default: pushBackToken(); return null;
+ default: pushBackToken(); return;
}
}
-
- /** return the largest expression beginning with prefix containing no operators of precedence below <tt>minPrecedence</tt> */
- public ForthBlock continueExpr(ForthBlock prefix, int minPrecedence) throws IOException {
- return continueExpr(prefix, minPrecedence, new ForthBlock(line, sourceName));
- }
- public ForthBlock continueExpr(ForthBlock prefix, int minPrecedence, ForthBlock appendTo) throws IOException {
+ public void continueExpr(CompiledFunction prefix, int minPrecedence) throws IOException {
int tok = getToken();
- int curLine = line;
- if (tok == -1) return prefix;
+ if (tok == -1) return;
if (minPrecedence > 0 && precedence[tok] != 0)
if (precedence[tok] < minPrecedence || (precedence[tok] == minPrecedence && !isRightAssociative[tok]))
- { pushBackToken(); return prefix; }
-
+ { pushBackToken(); return; }
if (prefix == null) throw new Error("got null prefix");
-
- ForthBlock b = appendTo;
+ CompiledFunction b = prefix;
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(b.EXPR, prefix);
prefix.set(prefix.size() - 1, b.GET_PRESERVE, new Boolean(true));
- prefix.add(prefix.EXPR, startExpr(precedence[tok - 1]));
- prefix.add(tok - 1);
- prefix.add(b.PUT);
- prefix.add(b.SWAP);
- prefix.add(b.POP);
- return continueExpr(b, minPrecedence);
+ startExpr(precedence[tok - 1], b);
+ prefix.add(line, tok - 1);
+ prefix.add(line, PUT);
+ prefix.add(line, SWAP);
+ prefix.add(line, POP);
+ continueExpr(b, minPrecedence);
+ return;
}
case INC: case DEC: {
// postfix
- prefix.set(prefix.size() - 1, tok, new Boolean(false));
- b.add(b.EXPR, prefix);
- return continueExpr(b, minPrecedence);
+ b.set(b.size() - 1, tok, new Boolean(false));
+ continueExpr(b, minPrecedence);
+ return;
}
case LP: {
// invocation
int i = 0;
- b.add(b.EXPR, prefix);
while(peekToken() != RP) {
- b.add(b.EXPR, startExpr());
i++;
+ startExpr(-1, b);
if (peekToken() == RP) break;
consume(COMMA);
}
consume(RP);
- b.add(b.CALL, new Integer(i));
- return continueExpr(b, minPrecedence);
+ b.add(line, CALL, new Integer(i));
+ continueExpr(b, minPrecedence);
+ return;
}
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: {
- b.add(b.EXPR, prefix);
- b.add(b.EXPR, startExpr(precedence[tok]));
- b.add(tok);
- return continueExpr(b, minPrecedence);
+ startExpr(precedence[tok], b);
+ b.add(line, tok);
+ continueExpr(b, minPrecedence);
+ return;
}
case OR: case AND: {
- 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);
- b.add(b.EXPR, startExpr(precedence[tok]));
- return continueExpr(b, minPrecedence);
+ b.add(line, tok == AND ? b.JF : b.JT, new Integer(0));
+ int size = b.size();
+ startExpr(precedence[tok], b);
+ b.set(size - 1, new Integer(b.size() - size + 2));
+ b.add(line, JMP, new Integer(2));
+ b.add(line, LITERAL, tok == AND ? new Boolean(false) : new Boolean(true));
+ continueExpr(b, minPrecedence);
+ return;
}
case DOT: {
consume(NAME);
String target = string;
- b.add(b.EXPR, prefix);
if (peekToken() == ASSIGN) {
consume(ASSIGN);
- ForthBlock val = startExpr();
- b.add(b.LITERAL, target);
- b.add(b.EXPR, val);
- b.add(b.PUT);
- b.add(b.SWAP);
- b.add(b.POP);
+ b.add(line, LITERAL, target);
+ startExpr(-1, b);
+ b.add(line, PUT);
+ b.add(line, SWAP);
+ b.add(line, POP);
} else {
- b.add(b.LITERAL, target);
- b.add(b.GET);
+ b.add(line, LITERAL, target);
+ b.add(line, GET);
}
- return continueExpr(b, minPrecedence);
+ continueExpr(b, minPrecedence);
+ return;
}
case LB: {
- b.add(b.EXPR, prefix);
- b.add(b.EXPR, startExpr());
+ startExpr(-1, b);
consume(RB);
if (peekToken() == ASSIGN) {
consume(ASSIGN);
- b.add(b.EXPR, startExpr());
- b.add(b.PUT);
- b.add(b.SWAP);
- b.add(b.POP);
+ startExpr(-1, b);
+ b.add(line, PUT);
+ b.add(line, SWAP);
+ b.add(line, POP);
} else {
- b.add(b.GET);
+ b.add(line, GET);
}
- return continueExpr(b, minPrecedence);
+ continueExpr(b, minPrecedence);
+ return;
}
case HOOK: {
- b.add(b.EXPR, prefix);
- b.add(b.JF, new Integer(3));
- b.add(b.EXPR, startExpr());
- b.add(b.JMP, new Integer(2));
+ b.add(line, JF, new Integer(0));
+ int size = b.size();
+ startExpr(-1, b);
+ b.set(size - 1, new Integer(b.size() - size + 2));
+ b.add(line, JMP, new Integer(0));
consume(COLON);
- b.add(b.EXPR, startExpr());
- return continueExpr(b, minPrecedence);
+ size = b.size();
+ startExpr(-1, b);
+ b.set(size - 1, new Integer(b.size() - size + 1));
+ continueExpr(b, minPrecedence);
+ return;
}
-
- default: pushBackToken(); return prefix;
+ default: { pushBackToken(); return; }
}
}
- /** a block is either a single statement or a list of statements surrounded by curly braces; all expressions are also statements */
- public ForthBlock parseStatement() throws IOException {
- ForthBlock ret = new ForthBlock(line, sourceName);
- ret.add(ret.LITERAL, null);
+ /**
+ * a block is either a single statement or a list of statements surrounded by curly braces;
+ * all expressions are also statements
+ */
+ public CompiledFunction parseStatement() throws IOException {
+ CompiledFunction ret = new CompiledFunction(sourceName, line, null);
+ ret.add(line, ret.LITERAL, null);
parseStatement(false, ret);
if (ret.size() == 1) return null;
return ret;
}
- public void parseStatement(boolean requireBraces) throws IOException {
- parseStatement(requireBraces, new ForthBlock(line, sourceName));
- }
- public void parseStatement(boolean requireBraces, ForthBlock b) throws IOException {
+ public void parseStatement(boolean r, CompiledFunction b) throws IOException { parseStatement(r, b, null); }
+ public void parseStatement(boolean requireBraces, CompiledFunction b, String label) throws IOException {
int tok = peekToken();
if (tok == -1) return;
+ int line = this.line;
boolean braced = tok == LC;
if (requireBraces && !braced) throw new ParserException("expected {, got " + codeToString[tok]);
if (braced) consume(LC);
- int curLine = line;
while(true) {
switch(tok = peekToken()) {
case THROW: case RETURN: case ASSERT: {
getToken();
- if (tok == RETURN && peekToken() == SEMI) b.add(b.LITERAL, null);
- else b.add(b.EXPR, startExpr());
+ if (tok == RETURN && peekToken() == SEMI) b.add(line, LITERAL, null);
+ else startExpr(-1, b);
consume(SEMI);
- b.add(tok);
+ b.add(line, tok);
break;
}
case BREAK: case CONTINUE: {
getToken();
if (peekToken() == NAME) consume(NAME);
- b.add(tok, string);
+ b.add(line, tok, string);
consume(SEMI);
break;
}
- case SEMI:
+ case SEMI: {
consume(SEMI);
if (!braced) return;
break;
+ }
case VAR: {
consume(VAR);
- b.add(THIS); // push the current scope
+ b.add(line, TOPSCOPE); // push the current scope
while(true) {
consume(NAME);
String name = string;
- b.add(b.LITERAL, name); // push the name to be declared
- b.add(b.DECLARE); // declare it
+ 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(b.LITERAL, name); // put the var name back on the stack
+ b.add(line, LITERAL, name); // put the var name back on the stack
consume(ASSIGN);
- b.add(b.EXPR, startExpr());
- b.add(b.PUT);
- b.add(b.POP);
+ startExpr(-1, b);
+ b.add(line, PUT);
+ b.add(line, POP);
}
if (peekToken() != COMMA) break;
consume(COMMA);
}
- b.add(b.POP);
+ b.add(line, POP);
if (peekToken() == SEMI) consume(SEMI);
break;
}
case IF: {
consume(IF);
consume(LP);
- b.add(b.EXPR, startExpr());
+ startExpr(-1, b);
consume(RP);
- b.add(b.JF, new Integer(4));
- b.add(b.EXPR, parseStatement());
- b.add(b.POP);
- b.add(b.JMP, new Integer(3));
+
+ b.add(line, JF, new Integer(0));
+ int size = b.size();
+ parseStatement(false, b);
+
if (peekToken() == ELSE) {
consume(ELSE);
- b.add(b.EXPR, parseStatement());
- b.add(b.POP);
- } else {
- b.add(b.JMP, new Integer(1)); // nop
- b.add(b.JMP, new Integer(1)); // nop
+ b.set(size - 1, new Integer(2 + b.size() - size));
+ b.add(line, JMP, new Integer(0));
+ size = b.size();
+ parseStatement(false, b);
}
+ b.set(size - 1, new Integer(1 + b.size() - size));
break;
}
case WHILE: {
consume(WHILE);
consume(LP);
- ForthBlock loop = new ForthBlock(curLine, sourceName);
- b.add(loop.LOOP, loop);
-
- loop.add(loop.POP);
- loop.add(loop.EXPR, startExpr());
- loop.add(loop.JT, new Integer(2));
- loop.add(Lexer.BREAK);
+ if (label != null) b.add(line, LABEL, label);
+ b.add(line, LOOP);
+ int size = b.size();
+ b.add(line, POP);
+ startExpr(-1, b);
+ b.add(line, JT, new Integer(2));
+ b.add(line, BREAK);
consume(RP);
- parseStatement(false, loop);
-
- // if we fall out of the end, definately continue
- loop.add(CONTINUE);
+ parseStatement(false, b);
+ 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(SWITCH);
consume(LP);
- ForthBlock loop = new ForthBlock(curLine, sourceName);
- b.add(loop.LOOP, loop);
- loop.add(loop.EXPR, startExpr());
+ if (label != null) b.add(line, LABEL, label);
+ b.add(line, LOOP);
+ int size0 = b.size();
+ startExpr(-1, b);
consume(RP);
consume(LC);
- while(true) {
- ForthBlock caseForthBlock;
- tok = getToken();
- if (tok == CASE) {
- loop.add(loop.DUP);
- loop.add(loop.EXPR, startExpr());
- loop.add(EQ);
- loop.add(loop.JF, new Integer(2));
- } else if (tok != DEFAULT) throw new ParserException("expected CASE or DEFAULT");
- consume(COLON);
- ForthBlock b2 = new ForthBlock(curLine, sourceName);
- ForthBlock e1 = null;
- while(peekToken() != CASE && peekToken() != DEFAULT && peekToken() != RC) {
- if ((e1 = parseStatement()) == null) break;
- b2.add(b.EXPR, e1);
- b2.add(b.POP);
- }
- loop.add(loop.EXPR, b2);
- if (peekToken() == RC) {
+ while(true)
+ if (peekToken() == CASE) {
+ consume(CASE);
+ b.add(line, DUP);
+ startExpr(-1, b);
+ 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(false, b);
+ 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(false, b);
+ if (size2 == b.size()) break;
+ }
+ } else if (peekToken() == RC) {
consume(RC);
- loop.add(BREAK);
+ 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: {
consume(DO);
- ForthBlock loop = new ForthBlock(curLine, sourceName);
- b.add(loop.LOOP, loop);
-
- parseStatement(false, loop);
+ if (label != null) b.add(line, LABEL, label);
+ b.add(line, LOOP);
+ int size = b.size();
+ parseStatement(false, b);
consume(WHILE);
consume(LP);
- loop.add(loop.EXPR, startExpr());
- loop.add(loop.JT, new Integer(2));
- loop.add(Lexer.BREAK);
- loop.add(Lexer.CONTINUE);
+ startExpr(-1, b);
+ 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: {
- // FIXME: don't just ignore this!
// We deliberately allow you to omit braces in catch{}/finally{} if they are single statements...
consume(TRY);
+ b.add(line, TRY);
+ int size = b.size();
parseStatement(true, b);
+ 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);
- parseStatement(); // just discard the catchblock
+ // 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(false, b);
}
+ 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(false, b);
break;
}
- case FOR: {
- consume(FOR);
- consume(LP);
-
- tok = getToken();
- if (tok == VAR) tok = getToken();
- String varName = string;
- boolean forIn = peekToken() == IN;
- pushBackToken(tok, varName);
-
- if (forIn) {
- consume(NAME);
- consume(IN);
- b.add(b.EXPR, startExpr());
- b.add(b.PUSHKEYS);
- b.add(b.LITERAL, "length");
- b.add(b.GET);
- consume(RP);
- ForthBlock b2 = new ForthBlock(curLine, sourceName);
- b.add(b.SCOPE, b2);
- b2.add(b.LITERAL, new Integer(1));
- b2.add(SUB);
- b2.add(b.DUP);
- b2.add(b.LITERAL, new Integer(0));
- b2.add(LT);
- b2.add(b.JT, new Integer(7));
- b2.add(b.GET_PRESERVE);
- b2.add(b.LITERAL, varName);
- b2.add(b.LITERAL, varName);
- b2.add(b.DECLARE);
- b2.add(b.PUT);
- b2.add(b.EXPR, parseStatement());
- //b2.add(b.LITERAL, null);
- break;
+ case FOR: {
+ consume(FOR);
+ consume(LP);
- } else {
- ForthBlock b2 = new ForthBlock(curLine, sourceName);
- b.add(b.SCOPE, b2);
- b.add(b.POP);
-
- ForthBlock e1 = startExpr();
- if (e1 == null) e1 = new ForthBlock(curLine, sourceName, b.LITERAL, null);
-
- b2.add(b.EXPR, e1);
- b2.add(b.POP);
- consume(SEMI);
- ForthBlock e2 = startExpr();
- consume(SEMI);
- ForthBlock e3 = startExpr();
- consume(RP);
-
- if (e2 == null) e2 = new ForthBlock(curLine, sourceName, b.LITERAL, null);
- if (e3 == null) e3 = new ForthBlock(curLine, sourceName, b.LITERAL, null);
-
- ForthBlock b3 = new ForthBlock(curLine, sourceName);
- b2.add(b.LOOP, b3);
- b2.add(b.LITERAL, null);
- b3.add(b.JT, new Integer(3));
- b3.add(b.EXPR, e3);
- b3.add(b.POP);
- b3.add(b.EXPR, e2);
- b3.add(b.JT, new Integer(2));
- b3.add(BREAK);
- parseStatement(false, b3);
- b3.add(BREAK);
- break;
+ 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(-1, b);
+ 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(false, b);
+
+ b.add(line, OLDSCOPE);
+
+ break;
+
+ } else {
+ if (hadVar) pushBackToken(VAR, null);
+ b.add(line, NEWSCOPE);
+
+ parseStatement(false, b);
+ CompiledFunction e2 = new CompiledFunction(sourceName, line, null);
+ startExpr(-1, e2);
+ consume(SEMI);
+ if (e2 == null) e2 = new CompiledFunction(sourceName, line, null).add(line, b.LITERAL, Boolean.TRUE);
+
+ 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();
+ startExpr(-1, b);
+ if (b.size() > size) 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(false, b);
+ 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: {
consume(NAME);
- String name = string;
+ String possiblyTheLabel = string;
if (peekToken() == COLON) {
consume(COLON);
- b.add(ForthBlock.LABEL, string);
+ label = possiblyTheLabel;
+ System.out.println("label == " + label);
+ parseStatement(false, b, label);
break;
} else {
- pushBackToken(NAME, name);
+ pushBackToken(NAME, possiblyTheLabel);
// fall through to default case
}
}
if (tok == RC && braced) { consume(RC); return; }
// fall through
default: {
- ForthBlock ret = startExpr();
- if (ret == null) return;
- b.add(b.EXPR, ret);
- b.add(b.POP);
+ int size = b.size();
+ startExpr(-1, b);
+ if (size == b.size()) return;
+ b.add(line, POP);
if (peekToken() == SEMI) consume(SEMI);
break;
}
}
}
- class ParserException extends RuntimeException {
+ private class ParserException extends RuntimeException {
public ParserException(String s) { super(sourceName + ":" + line + " " + s); }
}
projects / org.ibex.core.git / blobdiff