1 // Copyright 2006-2007 all rights reserved; see LICENSE file for BSD-style license
3 package edu.berkeley.sbp.meta;
4 import edu.berkeley.sbp.util.*;
5 import edu.berkeley.sbp.*;
6 import edu.berkeley.sbp.chr.*;
7 import edu.berkeley.sbp.misc.*;
9 import java.lang.annotation.*;
10 import java.lang.reflect.*;
14 * The inner classes of this class represent nodes in the Abstract
15 * Syntax Tree of a grammar.
17 public class GrammarAST {
19 public static interface ImportResolver {
20 public InputStream getImportStream(String importname);
24 * Returns a Union representing the metagrammar (<tt>meta.g</tt>); the Tree produced by
25 * parsing with this Union should be provided to <tt>buildFromAST</tt>
27 public static Union getMetaGrammar() {
28 return buildFromAST(MetaGrammar.meta, "s", null);
32 * Create a grammar from a parse tree and binding resolver
34 * @param t a tree produced by parsing a grammar using the metagrammar
35 * @param s the name of the "start symbol"
36 * @param gbr a GrammarBindingResolver that resolves grammatical reductions into tree-node-heads
38 public static Union buildFromAST(Tree grammarAST, String startingNonterminal, ImportResolver resolver) {
39 return new GrammarAST(resolver, "").buildGrammar(grammarAST, startingNonterminal);
42 public static void emitCode(PrintWriter pw, Tree grammarAST, String startingNonterminal, ImportResolver resolver) {
43 GrammarAST ga = new GrammarAST(resolver, "");
44 Object o = ga.walk(grammarAST);
45 GrammarAST.GrammarNode gn = (GrammarAST.GrammarNode)o;
46 EmitContext ecx = ga.new EmitContext(gn);
47 gn.emitCode(ecx, pw, "com.foo", "ClassName");
50 private static Object illegalTag = ""; // this is the tag that should never appear in the non-dropped output FIXME
52 // Instance //////////////////////////////////////////////////////////////////////////////
54 private final String prefix;
55 private final ImportResolver resolver;
57 public GrammarAST(ImportResolver resolver, String prefix) {
59 this.resolver = resolver;
62 // Methods //////////////////////////////////////////////////////////////////////////////
64 private Union buildGrammar(Tree t, String rootNonTerminal) {
66 if (o instanceof Union) return (Union)o;
67 return ((GrammarAST.GrammarNode)o).build(rootNonTerminal);
70 private Object[] walkChildren(Tree t) {
71 Object[] ret = new Object[t.size()];
72 for(int i=0; i<ret.length; i++)
73 ret[i] = walk(t.child(i));
74 return Reflection.lub(ret);
76 private static String stringifyChildren(Tree t) {
77 StringBuffer sb = new StringBuffer();
78 for(int i=0; i<t.size(); i++) {
79 sb.append(t.child(i).head());
80 sb.append(stringifyChildren(t.child(i)));
84 private static String unescape(Tree t) {
85 StringBuffer sb = new StringBuffer();
86 for(int i=0; i<t.size(); i++)
87 sb.append(t.child(i).head()+stringifyChildren(t.child(i)));
91 private ElementNode walkElement(Tree t) { return (ElementNode)walk(t); }
92 private String walkString(Tree t) { return (String)walk(t); }
93 private Seq walkSeq(Tree t) { return (Seq)walk(t); }
94 private Object walk(Tree t) {
95 String head = (String)t.head();
96 while(head.indexOf('.') > 0)
97 head = head.substring(head.indexOf('.')+1);
98 if (head==null) throw new RuntimeException("head is null: " + t);
99 if (head.equals("|")) return walkChildren(t);
100 if (head.equals("RHS")) return walkChildren(t);
101 if (head.equals("Grammar")) return new GrammarNode(walkChildren(t));
102 if (head.equals("(")) return new UnionNode((Seq[][])walkChildren(t.child(0)));
103 if (head.equals("Word")) return stringifyChildren(t);
104 if (head.equals("Elements")) return new Seq((ElementNode[])Reflection.rebuild(walkChildren(t), ElementNode[].class));
105 if (head.equals("NonTerminalReference")) return new ReferenceNode(stringifyChildren(t.child(0)));
106 if (head.equals(")")) return new ReferenceNode(stringifyChildren(t.child(0)), true);
107 if (head.equals(":")) return new LabelNode(stringifyChildren(t.child(0)), walkElement(t.child(1)));
108 if (head.equals("::")) return walkSeq(t.child(1)).tag(walkString(t.child(0)));
109 if (head.equals("...")) return new DropNode(new RepeatNode(new TildeNode(new AtomNode()), null, true, true, false));
111 if (head.equals("++")) return new RepeatNode(walkElement(t.child(0)), null, false, true, true);
112 if (head.equals("+")) return new RepeatNode(walkElement(t.child(0)), null, false, true, false);
113 if (head.equals("++/")) return new RepeatNode(walkElement(t.child(0)), walkElement(t.child(1)), false, true, true);
114 if (head.equals("+/")) return new RepeatNode(walkElement(t.child(0)), walkElement(t.child(1)), false, true, false);
115 if (head.equals("**")) return new RepeatNode(walkElement(t.child(0)), null, true, true, true);
116 if (head.equals("*")) return new RepeatNode(walkElement(t.child(0)), null, true, true, false);
117 if (head.equals("**/")) return new RepeatNode(walkElement(t.child(0)), walkElement(t.child(1)), true, true, true);
118 if (head.equals("*/")) return new RepeatNode(walkElement(t.child(0)), walkElement(t.child(1)), true, true, false);
119 if (head.equals("?")) return new RepeatNode(walkElement(t.child(0)), null, true, false, false);
121 if (head.equals("!")) return new DropNode(walkElement(t.child(0)));
122 if (head.equals("^")) return new LiteralNode(walkString(t.child(0)), true);
123 if (head.equals("`")) return new BacktickNode(walkElement(t.child(0)));
124 if (head.equals("Quoted")) return stringifyChildren(t);
125 if (head.equals("Literal")) return new LiteralNode(walkString(t.child(0)));
126 if (head.equals("->")) return walkSeq(t.child(0)).follow(walkElement(t.child(1)));
127 if (head.equals("DropNT")) return new NonTerminalNode(walkString(t.child(0)), (Seq[][])walkChildren(t.child(1)), false, null, true, false);
128 if (head.equals("=")) return new NonTerminalNode(walkString(t.child(0)), (Seq[][])walk(t.child(2)),
129 true, t.size()==2 ? null : walkString(t.child(1)), false, false);
130 if (head.equals("&")) return walkSeq(t.child(0)).and(walkSeq(t.child(1)));
131 if (head.equals("&~")) return walkSeq(t.child(0)).andnot(walkSeq(t.child(1)));
132 if (head.equals("/")) return (walkSeq(t.child(0))).separate(walkElement(t.child(1)));
133 if (head.equals("()")) return new LiteralNode("");
134 if (head.equals("[")) return new AtomNode((char[][])Reflection.rebuild(walkChildren(t), char[][].class));
135 if (head.equals("\\{")) return new DropNode(new AtomNode(new char[] { CharAtom.left, CharAtom.left }));
136 if (head.equals("\\}")) return new DropNode(new AtomNode(new char[] { CharAtom.right, CharAtom.right }));
137 if (head.equals(">>")) return new DropNode(new AtomNode(new char[] { CharAtom.left, CharAtom.left }));
138 if (head.equals("<<")) return new DropNode(new AtomNode(new char[] { CharAtom.right, CharAtom.right }));
139 if (head.equals("~")) return new TildeNode(walkElement(t.child(0)));
140 if (head.equals("~~")) return new Seq(new RepeatNode(new TildeNode(new AtomNode()), null, true, true, false)).andnot(walkSeq(t.child(0)));
141 if (head.equals("Range")) {
142 if (t.size()==2 && ">".equals(t.child(0).head())) return new char[] { CharAtom.left, CharAtom.left };
143 if (t.size()==2 && "<".equals(t.child(0).head())) return new char[] { CharAtom.right, CharAtom.right };
144 if (t.size()==1) return new char[] { unescape(t).charAt(0), unescape(t).charAt(0) };
145 return new char[] { unescape(t).charAt(0), unescape(t).charAt(1) };
147 if (head.equals("\"\"")) return "";
148 if (head.equals("\n")) return "\n";
149 if (head.equals("\t")) return "\t";
150 if (head.equals("\r")) return "\r";
151 if (head.equals("SubGrammar")) return GrammarAST.buildFromAST(t.child(0), "s", resolver);
152 if (head.equals("NonTerminal"))
153 return new NonTerminalNode(walkString(t.child(0)),
154 (Seq[][])walkChildren(t.child(1)), false, null, false, false);
155 if (head.equals("Colons")) {
156 String tag = walkString(t.child(0));
157 Seq[][] seqs = (Seq[][])walk(t.child(1));
158 for(Seq[] seq : seqs)
159 for(int i=0; i<seq.length; i++)
160 seq[i] = seq[i].tag(tag);
161 return new NonTerminalNode(tag, seqs, false, null, false, true);
163 if (head.equals("#import")) {
164 if (resolver != null) {
165 String fileName = (String)stringifyChildren(t.child(0));
167 String newPrefix = t.size()<2 ? "" : (walkString(t.child(1))+".");
168 InputStream fis = resolver.getImportStream(fileName);
170 throw new RuntimeException("unable to find #include file \""+fileName+"\"");
171 Tree tr = new CharParser(getMetaGrammar()).parse(fis).expand1();
172 return (GrammarNode)new GrammarAST(resolver, newPrefix).walk(tr);
173 } catch (Exception e) {
174 throw new RuntimeException("while parsing " + fileName, e);
177 throw new RuntimeException("no resolver given");
180 throw new RuntimeException("unknown head: \"" + head + "\" => " + (head.equals("...")));
184 // Nodes //////////////////////////////////////////////////////////////////////////////
186 /** Root node of a grammar's AST; a set of named nonterminals */
187 private class GrammarNode extends HashMap<String,NonTerminalNode> {
188 public GrammarNode(NonTerminalNode[] nonterminals) {
189 for(NonTerminalNode nt : nonterminals) {
190 if (nt==null) continue;
191 if (this.get(nt.name)!=null)
192 throw new RuntimeException("duplicate definition of nonterminal \""+nt.name+"\"");
193 this.put(nt.name, nt);
196 public GrammarNode(Object[] nt) { add(nt); }
197 private void add(Object o) {
199 else if (o instanceof Object[]) for(Object o2 : (Object[])o) add(o2);
200 else if (o instanceof NonTerminalNode) {
201 NonTerminalNode nt = (NonTerminalNode)o;
202 if (this.get(nt.name)!=null)
203 throw new RuntimeException("duplicate definition of nonterminal \""+nt.name+"\"");
204 this.put(nt.name, nt);
206 else if (o instanceof GrammarNode)
207 for(NonTerminalNode n : ((GrammarNode)o).values())
210 public String toString() {
212 for(NonTerminalNode nt : values()) ret += nt + ", ";
215 public Union build(String rootNonterminal) {
216 BuildContext cx = new BuildContext(this);
218 for(GrammarAST.NonTerminalNode nt : values())
219 if (nt.name.equals(rootNonterminal))
220 return (Union)cx.get(nt.name);
223 public void emitCode(EmitContext cx, PrintWriter pw, String packageName, String className) {
224 pw.println("package " + packageName + ";");
225 pw.println("public class " + className + " {");
226 // FIXME: root walking method
227 //pw.println(" public static XXX walk() root");
228 for(NonTerminalNode nt : values()) {
229 if (!(nt.name.charAt(0) >= 'A' && nt.name.charAt(0) <= 'Z')) continue;
230 StringBuffer fieldDeclarations = new StringBuffer();
231 StringBuffer walkCode = new StringBuffer();
232 nt.getUnionNode().emitCode(cx, fieldDeclarations, walkCode);
234 pw.println(" public static class " + nt.name + "{");
235 pw.println(fieldDeclarations);
237 pw.println(" public static " + nt.name + " walk"+nt.name+"(Tree t) {");
238 pw.println(" int i = 0;");
239 pw.println(walkCode);
242 // FIXME; list who extends it
243 pw.println(" public static interface " + nt.name + "{ }");
244 // FIXME: what on earth is this going to be?
245 pw.println(" public static " + nt.name + " walk"+nt.name+"(Tree t) {");
246 pw.println(" throw new Error(\"FIXME\");");
254 /** a NonTerminal is always a union at the top level */
255 private class NonTerminalNode {
256 public final boolean alwaysDrop;
257 public final String name;
258 public final ElementNode elementNode;
259 public final UnionNode unionNode;
260 public final boolean tagged;
261 public NonTerminalNode(String name, Seq[][] sequences, boolean rep, String sep, boolean alwaysDrop, boolean tagged) {
262 this.name = prefix + name;
263 this.alwaysDrop = alwaysDrop;
264 this.tagged = tagged;
265 this.unionNode = new UnionNode(sequences, rep, sep==null?null:(prefix + sep));
266 this.elementNode = alwaysDrop ? new DropNode(unionNode) : unionNode;
268 public boolean isDropped(Context cx) { return alwaysDrop; }
269 public Element build(BuildContext cx, NonTerminalNode cnt, boolean dropall) { return cx.get(name); }
270 public ElementNode getElementNode() { return elementNode; }
271 public UnionNode getUnionNode() { return unionNode; }
276 /** elements of the sequence */
277 ElementNode[] elements;
278 /** follow-set, if explicit */
280 /** tag to add when building the AST */
282 /** positive conjuncts */
283 HashSet<Seq> and = new HashSet<Seq>();
284 /** negative conjuncts */
285 HashSet<Seq> not = new HashSet<Seq>();
286 public boolean alwaysDrop = false;
288 public boolean isTagless() {
289 if (alwaysDrop) return true;
290 for(int i=0; i<elements.length; i++)
291 if ((elements[i] instanceof LiteralNode) && ((LiteralNode)elements[i]).caret)
293 if (tag==null) return true;
297 public boolean isDropped(Context cx) {
298 if (alwaysDrop) return true;
299 if (tag!=null) return false;
300 for(int i=0; i<elements.length; i++)
301 if (!elements[i].isDropped(cx) || ((elements[i] instanceof LiteralNode) && ((LiteralNode)elements[i]).caret))
305 public Seq(ElementNode e) { this(new ElementNode[] { e }); }
306 public Seq(ElementNode[] elements) { this(elements, true); }
307 public Seq(ElementNode[] el, boolean check) {
308 this.elements = new ElementNode[el.length];
309 System.arraycopy(el, 0, elements, 0, el.length);
310 for(int i=0; i<elements.length; i++) {
311 if (elements[i]==null)
312 throw new RuntimeException();
314 // FIXME: this whole mechanism is sketchy
316 for(int i=0; i<elements.length; i++) {
317 if ((elements[i] instanceof ReferenceNode) && ((ReferenceNode)elements[i]).parenthesized) {
318 ReferenceNode rn = (ReferenceNode)elements[i];
319 ElementNode replace = null;
320 for(int j=0; j<elements.length; j++) {
321 if (!(elements[j] instanceof ReferenceNode)) continue;
322 ReferenceNode rn2 = (ReferenceNode)elements[j];
323 if (rn2.nonTerminal.equals(rn.nonTerminal) && !rn2.parenthesized) {
324 if (replace == null) {
325 replace = new UnionNode(new Seq(rn2).andnot(new Seq(elements, false)));
327 elements[j] = replace;
333 public Atom toAtom(BuildContext cx) {
334 if (elements.length != 1)
335 throw new Error("you attempted to use ->, **, ++, or a similar character-class"+
336 " operator on a [potentially] multicharacter production");
337 return elements[0].toAtom(cx);
339 public Seq tag(String tag) { this.tag = tag; return this; }
340 public Seq follow(ElementNode follow) { this.follow = follow; return this; }
341 public Seq and(Seq s) { and.add(s); s.alwaysDrop = true; return this; }
342 public Seq andnot(Seq s) { not.add(s); s.alwaysDrop = true; return this; }
343 public Seq separate(ElementNode sep) {
344 ElementNode[] elements = new ElementNode[this.elements.length * 2 - 1];
345 for(int i=0; i<this.elements.length; i++) {
346 elements[i*2] = this.elements[i];
347 if (i<this.elements.length-1)
348 elements[i*2+1] = new DropNode(sep);
350 this.elements = elements;
353 public Sequence build(BuildContext cx, Union u, NonTerminalNode cnt, boolean dropall) {
354 Sequence ret = build0(cx, cnt, dropall);
355 for(Seq s : and) ret = ret.and(s.build(cx, null, cnt, true));
356 for(Seq s : not) ret = ret.andnot(s.build(cx, null, cnt, true));
357 if (u!=null) u.add(ret);
360 public Sequence build0(BuildContext cx, NonTerminalNode cnt, boolean dropall) {
361 boolean[] drops = new boolean[elements.length];
362 Element[] els = new Element[elements.length];
363 dropall |= isDropped(cx);
364 for(int i=0; i<elements.length; i++) {
365 if (dropall) drops[i] = true;
366 else drops[i] = elements[i].isDropped(cx);
367 if (elements[i] instanceof LiteralNode && ((LiteralNode)elements[i]).caret) {
368 if (tag != null) throw new RuntimeException("cannot have multiple tags in a sequence: " + this);
369 tag = ((LiteralNode)elements[i]).getLiteralTag();
374 boolean multiNonDrop = false;
375 for(int i=0; i<drops.length; i++)
377 if (idx==-1) idx = i;
378 else multiNonDrop = true;
379 for(int i=0; i<elements.length; i++) {
380 if (!multiNonDrop && i==idx && tag!=null && elements[i] instanceof RepeatNode) {
381 els[i] = ((RepeatNode)elements[i]).build(cx, cnt, dropall, tag);
384 els[i] = elements[i].build(cx, cnt, dropall);
386 if (tag==null && multiNonDrop)
387 throw new RuntimeException("multiple non-dropped elements in sequence: " + Sequence.create("", els));
388 boolean[] lifts = new boolean[elements.length];
389 for(int i=0; i<elements.length; i++)
390 lifts[i] = elements[i].isLifted();
394 ? Sequence.create(illegalTag, els)
395 : Sequence.create(tag, els, drops, lifts);
396 else if (tag==null) ret = Sequence.create(els, idx);
397 else ret = Sequence.create(tag, els, drops, lifts);
400 ret = Sequence.create(tag, els, drops, lifts);
401 if (this.follow != null)
402 ret = ret.followedBy(this.follow.toAtom(cx));
407 /** a node in the AST which is resolved into an Element */
408 private abstract class ElementNode {
409 /** the field name to be used when synthesizing AST classes; null if none suggested */
410 public String getFieldName() { return null; }
411 public boolean isLifted() { return false; }
412 public boolean isDropped(Context cx) { return false; }
413 //public abstract boolean isTagless();
414 public boolean isTagless() { return false; }
415 public void _emitCode(EmitContext cx,
416 StringBuffer fieldDeclarations,
417 StringBuffer walkCode) {
418 throw new RuntimeException("not implemented " + this.getClass().getName());
420 public final void emitCode(EmitContext cx,
421 StringBuffer fieldDeclarations,
422 StringBuffer walkCode) {
423 if (isDropped(cx)) return;
425 // parse just the literal text, create an int/float/char/string
426 // FIXME: how do we know which one?
427 walkCode.append(" stringify");
430 _emitCode(cx, fieldDeclarations, walkCode);
431 walkCode.append(" i++;");
433 public Atom toAtom(BuildContext cx) { throw new Error("can't convert a " + this.getClass().getName() + " to an atom: " + this); }
434 public abstract Element build(BuildContext cx, NonTerminalNode cnt, boolean dropall);
437 /** a union, produced by a ( .. | .. | .. ) construct */
438 private class UnionNode extends ElementNode {
440 /** each component of a union is a sequence */
441 public Seq[][] sequences;
443 /** if the union is a NonTerminal specified as Foo*=..., this is true */
446 /** if the union is a NonTerminal specified as Foo* /ws=..., then this is "ws" */
447 public String sep = null;
449 public UnionNode(Seq seq) { this(new Seq[][] { new Seq[] { seq } }); }
450 public UnionNode(Seq[][] sequences) { this(sequences, false, null); }
451 public UnionNode(Seq[][] sequences, boolean rep, String sep) {
452 this.sequences = sequences;
457 public boolean isTagless() {
458 for (Seq[] ss : sequences)
460 if (!s.isTagless()) return false;
464 public String[] getPossibleEmitClasses() {
465 HashSet<String> cl = new HashSet<String> ();
466 for(Seq[] ss : sequences)
469 String cls = s.getEmitClass();
470 if (cls != null) cl.add(cls);
473 return (String[])cl.toArray(new String[0]);
476 public void _emitCode(EmitContext cx,
477 StringBuffer fieldDeclarations,
478 StringBuffer walkCode) {
479 throw new RuntimeException("not implemented " + this.getClass().getName());
482 public String getFieldName() { return null; }
483 public boolean isLifted() { return false; }
484 public boolean isDropped(Context cx) {
485 for(Seq[] seqs : sequences)
487 if (!seq.isDropped(cx))
491 public Atom toAtom(BuildContext cx) {
493 for(Seq[] ss : sequences)
495 ret = ret==null ? s.toAtom(cx) : (Atom)ret.union(s.toAtom(cx));
499 public Element build(BuildContext cx, NonTerminalNode cnt, boolean dropall) {
500 return buildIntoPreallocatedUnion(cx, cnt, dropall, new Union(null, false)); }
501 public Element buildIntoPreallocatedUnion(BuildContext cx, NonTerminalNode cnt, boolean dropall, Union u) {
504 urep = new Union(null, false);
505 urep.add(Sequence.create(cnt.name, new Element[0]));
507 ? Sequence.create(new Element[] { u }, 0)
508 : Sequence.create(new Element[] { cx.get(sep), u }, 1));
510 HashSet<Sequence> bad2 = new HashSet<Sequence>();
511 for(int i=0; i<sequences.length; i++) {
512 Seq[] group = sequences[i];
513 Union u2 = new Union(null, false);
514 if (sequences.length==1) u2 = u;
515 for(int j=0; j<group.length; j++)
517 group[j].build(cx, u2, cnt, dropall);
519 Union u3 = new Union(null, false);
520 group[j].build(cx, u3, cnt, dropall);
521 Sequence s = Sequence.create(cnt.name,
522 new Element[] { u3, urep },
523 new boolean[] { false, false },
524 new boolean[] { false, true});
527 if (sequences.length==1) break;
528 Sequence seq = Sequence.create(u2);
529 for(Sequence s : bad2) seq = seq.andnot(s);
531 bad2.add(Sequence.create(u2));
537 /** reference to a NonTerminal by name */
538 private class ReferenceNode extends ElementNode {
539 public String nonTerminal;
540 public boolean parenthesized;
541 public ReferenceNode() { }
542 public ReferenceNode(String nonTerminal) { this(nonTerminal, false); }
543 public ReferenceNode(String nonTerminal, boolean parenthesized) {
544 this.nonTerminal = nonTerminal.indexOf('.')==-1 ? (prefix + nonTerminal) : nonTerminal;
545 this.parenthesized = parenthesized;
547 public NonTerminalNode resolve(Context cx) {
548 NonTerminalNode ret = cx.grammar.get(nonTerminal);
549 if (ret==null) throw new RuntimeException("undefined nonterminal: " + nonTerminal);
552 public Atom toAtom(BuildContext cx) {
553 ElementNode ret = cx.grammar.get(nonTerminal).getElementNode();
554 if (ret == null) throw new RuntimeException("unknown nonterminal \""+nonTerminal+"\"");
555 return ret.toAtom(cx);
557 public boolean isDropped(Context cx) { return resolve(cx).isDropped(cx); }
558 public Element build(BuildContext cx, NonTerminalNode cnt, boolean dropall) {
559 Element ret = cx.get(nonTerminal);
560 if (ret == null) throw new RuntimeException("unknown nonterminal \""+nonTerminal+"\"");
563 public String getFieldName() { return StringUtil.uncapitalize(nonTerminal); }
566 /** a literal string */
567 private class LiteralNode extends ElementNode {
568 private String string;
569 private final String thePrefix = prefix;
570 private boolean caret;
571 public LiteralNode(String string) { this(string, false); }
572 public LiteralNode(String string, boolean caret) {
573 this.string = string;
576 public String getLiteralTag() { return caret ? thePrefix+string : null; }
577 public String toString() { return "\""+string+"\""; }
578 public boolean isDropped(Context cx) { return true; }
579 public Atom toAtom(BuildContext cx) {
580 if (string.length()!=1) return super.toAtom(cx);
581 Range.Set set = new Range.Set();
582 set.add(string.charAt(0), string.charAt(0));
583 return CharAtom.set(set);
585 public Element build(BuildContext cx, NonTerminalNode cnt, boolean dropall) { return CharAtom.string(string); }
588 /** an atom (usually a character class) */
589 private class AtomNode extends ElementNode {
591 public AtomNode() { this(new char[0][]); }
592 public AtomNode(char[][] ranges) { this.ranges = ranges; }
593 public AtomNode(char[] range) { this.ranges = new char[][] { range }; }
594 public Element build(BuildContext cx, NonTerminalNode cnt, boolean dropall) { return toAtom(cx); }
595 public Atom toAtom(BuildContext cx) {
596 Range.Set set = new Range.Set();
597 for(char[] r : ranges) set.add(r[0], r[1]);
598 return CharAtom.set(set);
603 private class RepeatNode extends ElementNode {
604 public ElementNode e, sep;
605 public final boolean zero, many, max;
606 public RepeatNode(ElementNode e, ElementNode sep, boolean zero, boolean many, boolean max) {
607 this.e = e; this.sep = sep; this.zero = zero; this.many = many; this.max = max;
609 public Atom toAtom(BuildContext cx) { return sep==null ? e.toAtom(cx) : super.toAtom(cx); }
610 public boolean isDropped(Context cx) { return e.isDropped(cx); }
611 public Element build(BuildContext cx, NonTerminalNode cnt, boolean dropall) {
612 Element ret = build(cx, cnt, dropall, illegalTag);
613 String must = "must be tagged unless they appear within a dropped expression or their contents are dropped: ";
614 if (!dropall && !isDropped(cx) && !e.isDropped(cx))
615 if (!many) throw new RuntimeException("options (?) " + must + ret);
616 else if (zero) throw new RuntimeException("zero-or-more repetitions (*) " + must + ret);
617 else throw new RuntimeException("one-or-more repetitions (+) " + must + ret);
620 public Element build(BuildContext cx, NonTerminalNode cnt, boolean dropall, Object repeatTag) {
622 ? Repeat.repeat(e.build(cx, null, dropall), zero, many, sep==null ? null : sep.build(cx, null, dropall), repeatTag)
624 ? Repeat.repeatMaximal(e.toAtom(cx), zero, many, repeatTag)
625 : Repeat.repeatMaximal(e.build(cx, null, dropall), zero, many, sep.toAtom(cx), repeatTag);
629 /** helper class for syntactic constructs that wrap another construct */
630 private abstract class ElementNodeWrapper extends ElementNode {
631 protected ElementNode _e;
632 public ElementNodeWrapper(ElementNode e) { this._e = e; }
633 public boolean isDropped(Context cx) { return _e.isDropped(cx); }
634 public Atom toAtom(BuildContext cx) { return _e.toAtom(cx); }
635 public Element build(BuildContext cx, NonTerminalNode cnt, boolean dropall) { return _e.build(cx, cnt, dropall); }
636 public String getFieldName() { return _e.getFieldName(); }
637 public void _emitCode(EmitContext cx, StringBuffer fieldDeclarations, StringBuffer walkCode) {
638 _e._emitCode(cx, fieldDeclarations, walkCode);
642 /** a backtick node indicating that, when building the AST, the node's children should be inserted here */
643 private class BacktickNode extends ElementNodeWrapper {
644 public BacktickNode(ElementNode e) { super(e); }
645 public boolean isLifted() { return true; }
646 public String getFieldName() { throw new Error("FIXME: backtick isn't a single field"); }
647 public void _emitCode(EmitContext cx, StringBuffer fieldDeclarations, StringBuffer walkCode) {
648 _e._emitCode(cx, fieldDeclarations, walkCode);
653 private class TildeNode extends ElementNodeWrapper {
654 public TildeNode(ElementNode e) { super(e); }
655 public Atom toAtom(BuildContext cx) { return (Atom)((Topology<Character>)_e.toAtom(cx).complement()); }
656 public Element build(BuildContext cx, NonTerminalNode cnt, boolean dropall) { return toAtom(cx); }
659 private class DropNode extends ElementNodeWrapper {
660 public DropNode(ElementNode e) { super(e); }
661 public boolean isDropped(Context cx) { return true; }
664 /** provides a label on the fields of a Seq */
665 private class LabelNode extends ElementNodeWrapper {
666 public final String label;
667 public LabelNode(String label, ElementNode e) { super(e); this.label = label; }
668 public String getFieldName() { return label; }
671 //////////////////////////////////////////////////////////////////////////////
673 public class Context {
674 public HashMap<String,Union> map = new HashMap<String,Union>();
675 public GrammarNode grammar;
677 public Context(GrammarNode g) { this.grammar = g; }
681 public class EmitContext extends Context {
682 public EmitContext(GrammarNode g) { super(g); }
685 public class BuildContext extends Context {
686 public BuildContext(Tree t) { }
687 public BuildContext(GrammarNode g) { super(g); }
688 public Union build() {
690 for(NonTerminalNode nt : grammar.values()) {
691 Union u = get(nt.name);
692 if ("s".equals(nt.name))
697 public Union peek(String name) { return map.get(name); }
698 public void put(String name, Union u) { map.put(name, u); }
699 public Union get(String name) {
700 Union ret = map.get(name);
701 if (ret != null) return ret;
702 NonTerminalNode nt = grammar.get(name);
704 throw new Error("warning could not find " + name);
706 ret = new Union(name, false);
708 nt.getUnionNode().buildIntoPreallocatedUnion(this, nt, nt.isDropped(this), ret);