X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=inline;f=src%2Fedu%2Fberkeley%2Fsbp%2Fmeta%2FGrammarAST.java;h=297886b36f69cfe5427d71d5020aacf9a04b2dc5;hb=d474c27d3c37b00d2b2ec2dc62d123d69c8edac9;hp=fc76a0091652aab573776dd4ea481b6ffd3f0f3e;hpb=b3b610d65969bcd5325bdba70f9e9c9e03cc83b3;p=sbp.git
diff --git a/src/edu/berkeley/sbp/meta/GrammarAST.java b/src/edu/berkeley/sbp/meta/GrammarAST.java
index fc76a00..297886b 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 buildFromAST(MetaGrammar.meta, "s", new File[0]);
+ }
+
+ /**
* 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")) return walkSeq(t.child(0)).follow(walkElement(t.child(1)));
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));
@@ -119,16 +125,15 @@ public class GrammarAST {
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)),
@@ -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) {
@@ -156,7 +154,7 @@ public class GrammarAST {
try {
String newPrefix = t.size()<2 ? "" : (walkString(t.child(1))+".");
FileInputStream fis = new FileInputStream(file);
- Tree tr = new CharParser(MetaGrammar.newInstance()).parse(fis).expand1();
+ Tree tr = new CharParser(getMetaGrammar()).parse(fis).expand1();
return (GrammarNode)new GrammarAST(includes, newPrefix).walk(tr);
} catch (Exception e) {
throw new RuntimeException("while parsing " + file, e);
@@ -209,6 +207,14 @@ public class GrammarAST {
}
}
+ /** a node in the AST which is resolved into an Element */
+ private abstract class ElementNode {
+ public boolean isLifted() { return false; }
+ 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;
@@ -307,7 +313,6 @@ public class GrammarAST {
for(int i=0; i)_e.toAtom(cx).complement()); }
@@ -521,26 +518,6 @@ public class GrammarAST {
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 {