public class GrammarAST {
/**
+ * Returns a Union representing the metagrammar (<tt>meta.g</tt>); the Tree produced by
+ * parsing with this Union should be provided to <tt>buildFromAST</tt>
+ */
+ public static Union getMetaGrammar() {
+ return MetaGrammar.newInstance();
+ }
+
+ /**
* Create a grammar from a parse tree and binding resolver
*
* @param t a tree produced by parsing a grammar using the metagrammar
// Methods //////////////////////////////////////////////////////////////////////////////
private Union buildGrammar(Tree t, String rootNonTerminal) {
- return ((GrammarAST.GrammarNode)walk(t)).build(rootNonTerminal);
+ Object o = walk(t);
+ if (o instanceof Union) return (Union)o;
+ return ((GrammarAST.GrammarNode)o).build(rootNonTerminal);
}
- public Object[] walkChildren(Tree t) {
+ private Object[] walkChildren(Tree t) {
Object[] ret = new Object[t.size()];
- for(int i=0; i<ret.length; i++) {
+ for(int i=0; i<ret.length; i++)
ret[i] = walk(t.child(i));
- if (ret[i] instanceof Object[])
- ret[i] = Reflection.lub((Object[])ret[i]);
- }
return Reflection.lub(ret);
}
- private String stringifyChildren(Tree t) {
+ private static String stringifyChildren(Tree t) {
StringBuffer sb = new StringBuffer();
for(int i=0; i<t.size(); i++) {
sb.append(t.child(i).head());
}
return sb.toString();
}
- private String unescape(Tree t) {
+ private static String unescape(Tree t) {
StringBuffer sb = new StringBuffer();
for(int i=0; i<t.size(); i++)
sb.append(t.child(i).head()+stringifyChildren(t.child(i)));
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 BracedNode(walkSeq(t.child(0)));
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("DropNT")) return new NonTerminalNode(walkString(t.child(0)), (Seq[][])walkChildren(t.child(1)), false, null, true);
if (head.equals("=")) return new NonTerminalNode(walkString(t.child(0)), (Seq[][])walk(t.child(2)),
true, t.size()==2 ? null : walkString(t.child(1)), false);
- if (head.equals("&")) return and2(walkSeq(t.child(0)), walkSeq(t.child(1)));
- if (head.equals("&~")) return andnot2(walkSeq(t.child(0)), walkSeq(t.child(1)));
+ if (head.equals("&")) return walkSeq(t.child(0)).and(walkSeq(t.child(1)));
+ if (head.equals("&~")) return walkSeq(t.child(0)).andnot(walkSeq(t.child(1)));
if (head.equals("/")) return (walkSeq(t.child(0))).separate(walkElement(t.child(1)));
if (head.equals("()")) return new LiteralNode("");
if (head.equals("[")) return new AtomNode((char[][])Reflection.rebuild(walkChildren(t), char[][].class));
if (head.equals("<<")) return new DropNode(new AtomNode(new char[] { CharAtom.right, CharAtom.right }));
if (head.equals("~")) return new TildeNode(walkElement(t.child(0)));
if (head.equals("~~")) return new Seq(new RepeatNode(new TildeNode(new AtomNode()), null, true, true, false)).andnot(walkSeq(t.child(0)));
- if (head.equals("Range") && t.size()==2 && ">".equals(t.child(0).head()))
- return new char[] { CharAtom.left, CharAtom.left };
- if (head.equals("Range") && t.size()==2 && "<".equals(t.child(0).head()))
- return new char[] { CharAtom.right, CharAtom.right };
- if (head.equals("Range") && t.size()==1) return new char[] { unescape(t).charAt(0), unescape(t).charAt(0) };
- if (head.equals("Range")) return new char[] { unescape(t).charAt(0), unescape(t).charAt(1) };
+ if (head.equals("Range")) {
+ if (t.size()==2 && ">".equals(t.child(0).head())) return new char[] { CharAtom.left, CharAtom.left };
+ if (t.size()==2 && "<".equals(t.child(0).head())) return new char[] { CharAtom.right, CharAtom.right };
+ if (t.size()==1) return new char[] { unescape(t).charAt(0), unescape(t).charAt(0) };
+ return new char[] { unescape(t).charAt(0), unescape(t).charAt(1) };
+ }
if (head.equals("\"\"")) return "";
- if (head.equals("\n")) return "\n";
- if (head.equals("\r")) return "\r";
- if (head.equals("grammar.Grammar")) return walkChildren(t);
+ if (head.equals("\n")) return "\n";
+ if (head.equals("\r")) return "\r";
if (head.equals("SubGrammar")) return GrammarAST.buildFromAST(t.child(0), "s", includes);
if (head.equals("NonTerminal"))
return new NonTerminalNode(walkString(t.child(0)),
seq[i] = seq[i].tag(tag);
return new NonTerminalNode(tag, seqs, false, null, false);
}
- if (head.equals("TestCase"))
- return new RegressionTests.TestCase(walkString(t.child(0)),
- walkString(t.child(1)),
- (String[])Reflection.coerce(walkChildren(t.child(2)), String[].class),
- (Union)walk(t.child(3)),
- false,
- false);
if (head.equals("#import")) {
String fileName = (String)stringifyChildren(t.child(0));
for(File f : includes) {
}
}
+ private abstract class ElementNode {
+ public boolean lifted = false;
+ public Seq ownerSeq = null;
+ public ElementNode lifted() { this.lifted = true; return this; }
+ public boolean drop(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 Seq tag(String tag) { this.tag = tag; return this; }
public Seq follow(ElementNode follow) { this.follow = follow; return this; }
- public Seq and(Seq s) { and.add(s); return this; }
- public Seq andnot(Seq s) { not.add(s); return this; }
+ public Seq and(Seq s) { and.add(s); s.alwaysDrop = true; return this; }
+ public Seq andnot(Seq s) { not.add(s); s.alwaysDrop = true; return this; }
public Seq separate(ElementNode sep) {
ElementNode[] elements = new ElementNode[this.elements.length * 2 - 1];
for(int i=0; i<this.elements.length; i++) {
for(int i=0; i<elements.length; i++) {
if (dropall) drops[i] = true;
else drops[i] = elements[i].drop(cx);
- if (elements[i].getOwnerTag() != null)
- tag = elements[i].getOwnerTag();
+ if (elements[i] instanceof LiteralNode && ((LiteralNode)elements[i]).caret) {
+ if (tag != null) throw new RuntimeException("cannot have multiple tags in a sequence: " + this);
+ tag = ((LiteralNode)elements[i]).getLiteralTag();
+ }
}
Sequence ret = null;
int idx = -1;
}
public boolean drop(Context cx) { return resolve(cx).drop(cx); }
public Element build(Context cx, NonTerminalNode cnt, boolean dropall) {
- /*
- if (!this.nonTerminal.startsWith(prefix))
- nonTerminal = prefix + nonTerminal;
- */
Element ret = cx.get(nonTerminal);
if (ret == null) throw new RuntimeException("unknown nonterminal \""+nonTerminal+"\"");
return ret;
this.string = string;
this.caret = caret;
}
- public String getOwnerTag() { return caret ? thePrefix+string : super.getOwnerTag(); }
+ public String getLiteralTag() { return caret ? thePrefix+string : null; }
public String toString() { return "\""+string+"\""; }
public boolean drop(Context cx) { return true; }
public Atom toAtom(Context cx) {
}
}
- private abstract class ElementNode {
- public boolean lifted = false;
- public Seq ownerSeq = null;
- public String getOwnerTag() { return null; }
- public ElementNode lifted() { this.lifted = true; return this; }
- public boolean drop(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 abstract class ElementNodeWrapper extends ElementNode {
protected ElementNode _e;
public ElementNodeWrapper(ElementNode e) { this._e = e; }
- public String getOwnerTag() { return _e.getOwnerTag(); }
public boolean drop(Context cx) { return _e.drop(cx); }
public Atom toAtom(Context cx) { return _e.toAtom(cx); }
public Element build(Context cx, NonTerminalNode cnt, boolean dropall) { return _e.build(cx, cnt, dropall); }
public boolean drop(Context cx) { return true; }
}
- // FIXME: doesn't this require a tag?
- private class BracedNode extends ElementNode {
- public Seq body;
- public BracedNode(Seq seq) { this.body = seq; }
- public Element build(Context cx, NonTerminalNode cnt, boolean dropall) {
- Union u = new Union(null, false);
- Sequence s = body.build(cx, u, null, dropall);
- Union u2 = new Union(null, false);
- u2.add(Sequence.create(new Element[] {
- CharAtom.leftBrace,
- u,
- CharAtom.rightBrace
- }, 1));
- return u2;
- }
- }
-
- public Seq and2(Seq s, Seq a) { a.alwaysDrop = true; return s.and(a); }
- public Seq andnot2(Seq s, Seq a) { a.alwaysDrop = true; return s.andnot(a); }
-
//////////////////////////////////////////////////////////////////////////////
public class Context {
projects / sbp.git / blobdiff