if (head.equals("Elements")) return new Seq((ElementNode[])Reflection.rebuild(walkChildren(t), ElementNode[].class));
if (head.equals("NonTerminalReference")) return new ReferenceNode(stringifyChildren(t.child(0)));
if (head.equals(")")) return new ReferenceNode(stringifyChildren(t.child(0)), true);
+ if (head.equals(":")) return new LabelNode(stringifyChildren(t.child(0)), walkElement(t.child(1)));
if (head.equals("::")) return walkSeq(t.child(1)).tag(walkString(t.child(0)));
if (head.equals("...")) return new DropNode(new RepeatNode(new TildeNode(new AtomNode()), null, true, true, false));
}
if (head.equals("\"\"")) return "";
if (head.equals("\n")) return "\n";
+ if (head.equals("\t")) return "\t";
if (head.equals("\r")) return "\r";
if (head.equals("SubGrammar")) return GrammarAST.buildFromAST(t.child(0), "s", resolver);
if (head.equals("NonTerminal"))
}
}
- /** a node in the AST which is resolved into an Element */
- private abstract class ElementNode {
- public boolean isLifted() { return false; }
- public boolean isDropped(Context cx) { return false; }
- public Atom toAtom(Context cx) { throw new Error("can't convert a " + this.getClass().getName() + " to an atom: " + this); }
- public abstract Element build(Context cx, NonTerminalNode cnt, boolean dropall);
- }
-
- private class UnionNode extends ElementNode {
- public Seq[][] sequences;
- public String sep = null;
- public boolean rep;
- public UnionNode(Seq seq) { this(new Seq[][] { new Seq[] { seq } }); }
- public UnionNode(Seq[][] sequences) { this(sequences, false, null); }
- public UnionNode(Seq[][] sequences, boolean rep, String sep) {
- this.sequences = sequences;
- this.rep = rep;
- this.sep = sep;
- }
- public boolean isDropped(Context cx) {
- for(Seq[] seqs : sequences)
- for(Seq seq : seqs)
- if (!seq.isDropped(cx))
- return false;
- return true;
- }
- public Atom toAtom(Context cx) {
- Atom ret = null;
- for(Seq[] ss : sequences)
- for(Seq s : ss)
- ret = ret==null ? s.toAtom(cx) : (Atom)ret.union(s.toAtom(cx));
- return ret;
- }
- public Element build(Context cx, NonTerminalNode cnt, boolean dropall) {
- return buildIntoPreallocatedUnion(cx, cnt, dropall, new Union(null, false)); }
- public Element buildIntoPreallocatedUnion(Context cx, NonTerminalNode cnt, boolean dropall, Union u) {
- Union urep = null;
- if (rep) {
- urep = new Union(null, false);
- urep.add(Sequence.create(cnt.name, new Element[0]));
- urep.add(sep==null
- ? Sequence.create(new Element[] { u }, 0)
- : Sequence.create(new Element[] { cx.get(sep), u }, 1));
- }
- HashSet<Sequence> bad2 = new HashSet<Sequence>();
- for(int i=0; i<sequences.length; i++) {
- Seq[] group = sequences[i];
- Union u2 = new Union(null, false);
- if (sequences.length==1) u2 = u;
- for(int j=0; j<group.length; j++)
- if (!rep)
- group[j].build(cx, u2, cnt, dropall);
- else {
- Union u3 = new Union(null, false);
- group[j].build(cx, u3, cnt, dropall);
- Sequence s = Sequence.create(cnt.name,
- new Element[] { u3, urep },
- new boolean[] { false, false },
- new boolean[] { false, true});
- u2.add(s);
- }
- if (sequences.length==1) break;
- Sequence seq = Sequence.create(u2);
- for(Sequence s : bad2) seq = seq.andnot(s);
- u.add(seq);
- bad2.add(Sequence.create(u2));
- }
- return u;
- }
- }
-
- private class NonTerminalNode extends UnionNode {
- public boolean alwaysDrop;
- public String name = null;
- public boolean isDropped(Context cx) { return alwaysDrop; }
+ /** a NonTerminal is always a union at the top level */
+ private class NonTerminalNode {
+ public final boolean alwaysDrop;
+ public final String name;
+ public final ElementNode elementNode;
+ public final UnionNode unionNode;
public NonTerminalNode(String name, Seq[][] sequences, boolean rep, String sep, boolean alwaysDrop) {
- super(sequences, rep, sep==null?null:(prefix + sep));
this.name = prefix + name;
this.alwaysDrop = alwaysDrop;
+ this.unionNode = new UnionNode(sequences, rep, sep==null?null:(prefix + sep));
+ this.elementNode = alwaysDrop ? new DropNode(unionNode) : unionNode;
}
+ public boolean isDropped(Context cx) { return alwaysDrop; }
public Element build(Context cx, NonTerminalNode cnt, boolean dropall) { return cx.get(name); }
+ public ElementNode getElementNode() { return elementNode; }
+ public UnionNode getUnionNode() { return unionNode; }
}
+ /** a sequence */
private class Seq {
+ /** elements of the sequence */
+ ElementNode[] elements;
+ /** follow-set, if explicit */
+ ElementNode follow;
+ /** tag to add when building the AST */
+ String tag = null;
+ /** positive conjuncts */
+ HashSet<Seq> and = new HashSet<Seq>();
+ /** negative conjuncts */
+ HashSet<Seq> not = new HashSet<Seq>();
public boolean alwaysDrop = false;
public boolean isDropped(Context cx) {
if (alwaysDrop) return true;
if (tag!=null) return false;
for(int i=0; i<elements.length; i++)
- if (!elements[i].isDropped(cx))
+ if (!elements[i].isDropped(cx) || ((elements[i] instanceof LiteralNode) && ((LiteralNode)elements[i]).caret))
return false;
return true;
}
- HashSet<Seq> and = new HashSet<Seq>();
- HashSet<Seq> not = new HashSet<Seq>();
- ElementNode[] elements;
- ElementNode follow;
- String tag = null;
public Seq(ElementNode e) { this(new ElementNode[] { e }); }
public Seq(ElementNode[] elements) { this(elements, true); }
public Seq(ElementNode[] el, boolean check) {
}
}
+ /** a node in the AST which is resolved into an Element */
+ private abstract class ElementNode {
+ /** the field name to be used when synthesizing AST classes; null if none suggested */
+ public String getFieldName() { return null; }
+ public boolean isLifted() { return false; }
+ public boolean isDropped(Context cx) { return false; }
+ public Atom toAtom(Context cx) { throw new Error("can't convert a " + this.getClass().getName() + " to an atom: " + this); }
+ public abstract Element build(Context cx, NonTerminalNode cnt, boolean dropall);
+ }
+
+ /** a union, produced by a ( .. | .. | .. ) construct */
+ private class UnionNode extends ElementNode {
+
+ /** each component of a union is a sequence */
+ public Seq[][] sequences;
+
+ /** if the union is a NonTerminal specified as Foo*=..., this is true */
+ public boolean rep;
+
+ /** if the union is a NonTerminal specified as Foo* /ws=..., then this is "ws" */
+ public String sep = null;
+
+ public UnionNode(Seq seq) { this(new Seq[][] { new Seq[] { seq } }); }
+ public UnionNode(Seq[][] sequences) { this(sequences, false, null); }
+ public UnionNode(Seq[][] sequences, boolean rep, String sep) {
+ this.sequences = sequences;
+ this.rep = rep;
+ this.sep = sep;
+ }
+ public String getFieldName() { return null; }
+ public boolean isLifted() { return false; }
+ public boolean isDropped(Context cx) {
+ for(Seq[] seqs : sequences)
+ for(Seq seq : seqs)
+ if (!seq.isDropped(cx))
+ return false;
+ return true;
+ }
+ public Atom toAtom(Context cx) {
+ Atom ret = null;
+ for(Seq[] ss : sequences)
+ for(Seq s : ss)
+ ret = ret==null ? s.toAtom(cx) : (Atom)ret.union(s.toAtom(cx));
+ return ret;
+ }
+
+ public Element build(Context cx, NonTerminalNode cnt, boolean dropall) {
+ return buildIntoPreallocatedUnion(cx, cnt, dropall, new Union(null, false)); }
+ public Element buildIntoPreallocatedUnion(Context cx, NonTerminalNode cnt, boolean dropall, Union u) {
+ Union urep = null;
+ if (rep) {
+ urep = new Union(null, false);
+ urep.add(Sequence.create(cnt.name, new Element[0]));
+ urep.add(sep==null
+ ? Sequence.create(new Element[] { u }, 0)
+ : Sequence.create(new Element[] { cx.get(sep), u }, 1));
+ }
+ HashSet<Sequence> bad2 = new HashSet<Sequence>();
+ for(int i=0; i<sequences.length; i++) {
+ Seq[] group = sequences[i];
+ Union u2 = new Union(null, false);
+ if (sequences.length==1) u2 = u;
+ for(int j=0; j<group.length; j++)
+ if (!rep)
+ group[j].build(cx, u2, cnt, dropall);
+ else {
+ Union u3 = new Union(null, false);
+ group[j].build(cx, u3, cnt, dropall);
+ Sequence s = Sequence.create(cnt.name,
+ new Element[] { u3, urep },
+ new boolean[] { false, false },
+ new boolean[] { false, true});
+ u2.add(s);
+ }
+ if (sequences.length==1) break;
+ Sequence seq = Sequence.create(u2);
+ for(Sequence s : bad2) seq = seq.andnot(s);
+ u.add(seq);
+ bad2.add(Sequence.create(u2));
+ }
+ return u;
+ }
+ }
+
+ /** reference to a NonTerminal by name */
private class ReferenceNode extends ElementNode {
public String nonTerminal;
public boolean parenthesized;
return ret;
}
public Atom toAtom(Context cx) {
- ElementNode ret = cx.grammar.get(nonTerminal);
+ ElementNode ret = cx.grammar.get(nonTerminal).getElementNode();
if (ret == null) throw new RuntimeException("unknown nonterminal \""+nonTerminal+"\"");
return ret.toAtom(cx);
}
}
}
+ /** a literal string */
private class LiteralNode extends ElementNode {
private String string;
private final String thePrefix = prefix;
public Element build(Context cx, NonTerminalNode cnt, boolean dropall) { return CharAtom.string(string); }
}
+ /** an atom (usually a character class) */
private class AtomNode extends ElementNode {
char[][] ranges;
public AtomNode() { this(new char[0][]); }
}
}
+ /** a repetition */
private class RepeatNode extends ElementNode {
public ElementNode e, sep;
public final boolean zero, many, max;
}
}
+ /** helper class for syntactic constructs that wrap another construct */
private abstract class ElementNodeWrapper extends ElementNode {
protected ElementNode _e;
public ElementNodeWrapper(ElementNode e) { this._e = e; }
public Element build(Context cx, NonTerminalNode cnt, boolean dropall) { return _e.build(cx, cnt, dropall); }
}
+ /** a backtick node indicating that, when building the AST, the node's children should be inserted here */
private class BacktickNode extends ElementNodeWrapper {
public BacktickNode(ElementNode e) { super(e); }
public boolean isLifted() { return true; }
}
+ /** negation */
private class TildeNode extends ElementNodeWrapper {
public TildeNode(ElementNode e) { super(e); }
public Atom toAtom(Context cx) { return (Atom)((Topology<Character>)_e.toAtom(cx).complement()); }
public boolean isDropped(Context cx) { return true; }
}
+ /** provides a label on the fields of a Seq */
+ private class LabelNode extends ElementNodeWrapper {
+ public final String label;
+ public LabelNode(String label, ElementNode e) { super(e); this.label = label; }
+ }
+
//////////////////////////////////////////////////////////////////////////////
public class Context {
} else {
ret = new Union(name, false);
map.put(name, ret);
- nt.buildIntoPreallocatedUnion(this, nt, nt.isDropped(this), ret);
+ nt.getUnionNode().buildIntoPreallocatedUnion(this, nt, nt.isDropped(this), ret);
}
return ret;
}
projects / sbp.git / blobdiff