X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2Fmeta%2FGrammarAST.java;fp=src%2Fedu%2Fberkeley%2Fsbp%2Fmeta%2FGrammarAST.java;h=046c3ac6a039f1a24110bb0493d62649e6da95a4;hp=297886b36f69cfe5427d71d5020aacf9a04b2dc5;hb=5fa948c7db9597445448194418537a1c74f46a27;hpb=9e1149086929874c9e7bd09daaef22f55432f750
diff --git a/src/edu/berkeley/sbp/meta/GrammarAST.java b/src/edu/berkeley/sbp/meta/GrammarAST.java
index 297886b..046c3ac 100644
--- a/src/edu/berkeley/sbp/meta/GrammarAST.java
+++ b/src/edu/berkeley/sbp/meta/GrammarAST.java
@@ -16,12 +16,16 @@ import java.io.*;
*/
public class GrammarAST {
+ public static interface ImportResolver {
+ public InputStream getImportStream(String importname);
+ }
+
/**
* 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]);
+ return buildFromAST(MetaGrammar.meta, "s", null);
}
/**
@@ -31,8 +35,8 @@ public class GrammarAST {
* @param s the name of the "start symbol"
* @param gbr a GrammarBindingResolver that resolves grammatical reductions into tree-node-heads
*/
- public static Union buildFromAST(Tree grammarAST, String startingNonterminal, File[] includes) {
- return new GrammarAST(includes, "").buildGrammar(grammarAST, startingNonterminal);
+ public static Union buildFromAST(Tree grammarAST, String startingNonterminal, ImportResolver resolver) {
+ return new GrammarAST(resolver, "").buildGrammar(grammarAST, startingNonterminal);
}
private static Object illegalTag = ""; // this is the tag that should never appear in the non-dropped output FIXME
@@ -40,11 +44,11 @@ public class GrammarAST {
// Instance //////////////////////////////////////////////////////////////////////////////
private final String prefix;
- private final File[] includes;
+ private final ImportResolver resolver;
- public GrammarAST(File[] includes, String prefix) {
+ public GrammarAST(ImportResolver resolver, String prefix) {
this.prefix = prefix;
- this.includes = includes;
+ this.resolver = resolver;
}
// Methods //////////////////////////////////////////////////////////////////////////////
@@ -134,7 +138,7 @@ public class GrammarAST {
if (head.equals("\"\"")) return "";
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("SubGrammar")) return GrammarAST.buildFromAST(t.child(0), "s", resolver);
if (head.equals("NonTerminal"))
return new NonTerminalNode(walkString(t.child(0)),
(Seq[][])walkChildren(t.child(1)), false, null, false);
@@ -147,20 +151,21 @@ public class GrammarAST {
return new NonTerminalNode(tag, seqs, false, null, false);
}
if (head.equals("#import")) {
- String fileName = (String)stringifyChildren(t.child(0));
- for(File f : includes) {
- File file = new File(f.getAbsolutePath()+File.separatorChar+fileName);
- if (!file.exists()) continue;
+ if (resolver != null) {
+ String fileName = (String)stringifyChildren(t.child(0));
try {
String newPrefix = t.size()<2 ? "" : (walkString(t.child(1))+".");
- FileInputStream fis = new FileInputStream(file);
+ InputStream fis = resolver.getImportStream(fileName);
+ if (fis==null)
+ throw new RuntimeException("unable to find #include file \""+fileName+"\"");
Tree tr = new CharParser(getMetaGrammar()).parse(fis).expand1();
- return (GrammarNode)new GrammarAST(includes, newPrefix).walk(tr);
+ return (GrammarNode)new GrammarAST(resolver, newPrefix).walk(tr);
} catch (Exception e) {
- throw new RuntimeException("while parsing " + file, e);
+ throw new RuntimeException("while parsing " + fileName, e);
}
+ } else {
+ throw new RuntimeException("no resolver given");
}
- throw new RuntimeException("unable to find #include file \""+fileName+"\"");
}
throw new RuntimeException("unknown head: \"" + head + "\" => " + (head.equals("...")));
}
@@ -210,7 +215,7 @@ 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 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);
}
@@ -226,10 +231,10 @@ public class GrammarAST {
this.rep = rep;
this.sep = sep;
}
- public boolean drop(Context cx) {
+ public boolean isDropped(Context cx) {
for(Seq[] seqs : sequences)
for(Seq seq : seqs)
- if (!seq.drop(cx))
+ if (!seq.isDropped(cx))
return false;
return true;
}
@@ -281,7 +286,7 @@ public class GrammarAST {
private class NonTerminalNode extends UnionNode {
public boolean alwaysDrop;
public String name = null;
- public boolean drop(Context cx) { return alwaysDrop; }
+ public boolean isDropped(Context cx) { return alwaysDrop; }
public NonTerminalNode(String name, Seq[][] sequences, boolean rep, String sep, boolean alwaysDrop) {
super(sequences, rep, sep==null?null:(prefix + sep));
this.name = prefix + name;
@@ -292,11 +297,11 @@ public class GrammarAST {
private class Seq {
public boolean alwaysDrop = false;
- public boolean drop(Context cx) {
+ public boolean isDropped(Context cx) {
if (alwaysDrop) return true;
if (tag!=null) return false;
for(int i=0; i