X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2Fmeta%2FGrammarAST.java;h=05c7b39dc7394dac4cc448b59f5a6dbc70f76422;hp=fc76a0091652aab573776dd4ea481b6ffd3f0f3e;hb=013262fd96a3dfc4c2cd7a0ba320dd7981ce678c;hpb=b3b610d65969bcd5325bdba70f9e9c9e03cc83b3
diff --git a/src/edu/berkeley/sbp/meta/GrammarAST.java b/src/edu/berkeley/sbp/meta/GrammarAST.java
index fc76a00..05c7b39 100644
--- a/src/edu/berkeley/sbp/meta/GrammarAST.java
+++ b/src/edu/berkeley/sbp/meta/GrammarAST.java
@@ -1,4 +1,4 @@
-// Copyright 2006 all rights reserved; see LICENSE file for BSD-style license
+// Copyright 2006-2007 all rights reserved; see LICENSE file for BSD-style license
package edu.berkeley.sbp.meta;
import edu.berkeley.sbp.util.*;
@@ -17,6 +17,14 @@ import java.io.*;
public class GrammarAST {
/**
+ * Returns a Union representing the metagrammar (meta.g); the Tree produced by
+ * parsing with this Union should be provided to buildFromAST
+ */
+ 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
@@ -42,19 +50,18 @@ public class GrammarAST {
// 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".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)),
@@ -141,13 +146,6 @@ public class GrammarAST {
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) {
@@ -209,6 +207,15 @@ public class GrammarAST {
}
}
+ 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;
@@ -336,8 +343,8 @@ public class GrammarAST {
}
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