/*
* [The "BSD license"]
* Copyright (c) 2010 Terence Parr
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
Please excuse my obvious lack of Java experience. The code here is probably
full of WTFs - though IMHO Java is the Real WTF(TM) here...
*/
package org.antlr.codegen;
import org.antlr.runtime.Token;
import org.antlr.tool.Grammar;
import java.util.ArrayList;
import java.util.List;
public class PythonTarget extends Target {
@Override
public boolean useBaseTemplatesForSynPredFragments() {
return false;
}
Target must be able to override the labels used for token types /** Target must be able to override the labels used for token types */
@Override
public String getTokenTypeAsTargetLabel(CodeGenerator generator,
int ttype) {
// use ints for predefined types;
// <invalid> <EOR> <DOWN> <UP>
if ( ttype >= 0 && ttype <= 3 ) {
return String.valueOf(ttype);
}
String name = generator.grammar.getTokenDisplayName(ttype);
// If name is a literal, return the token type instead
if ( name.charAt(0)=='\'' ) {
return String.valueOf(ttype);
}
return name;
}
@Override
public String getTargetCharLiteralFromANTLRCharLiteral(
CodeGenerator generator,
String literal) {
int c = Grammar.getCharValueFromGrammarCharLiteral(literal);
return String.valueOf(c);
}
private List<String> splitLines(String text) {
ArrayList<String> l = new ArrayList<String>();
int idx = 0;
while ( true ) {
int eol = text.indexOf("\n", idx);
if ( eol == -1 ) {
l.add(text.substring(idx));
break;
}
else {
l.add(text.substring(idx, eol+1));
idx = eol+1;
}
}
return l;
}
@Override
public List<Object> postProcessAction(List<Object> chunks, Token actionToken) {
/* TODO
- check for and report TAB usage
*/
//System.out.println("\n*** Action at " + actionToken.getLine() + ":" + actionToken.getColumn());
/* First I create a new list of chunks. String chunks are splitted into
lines and some whitespace my be added at the beginning.
As a result I get a list of chunks
- where the first line starts at column 0
- where every LF is at the end of a string chunk
*/
List<Object> nChunks = new ArrayList<Object>();
for (int i = 0; i < chunks.size(); i++) {
Object chunk = chunks.get(i);
if ( chunk instanceof String ) {
String text = (String)chunks.get(i);
if ( nChunks.isEmpty() && actionToken.getCharPositionInLine() >= 0 ) {
// first chunk and some 'virtual' WS at beginning
// prepend to this chunk
String ws = "";
for ( int j = 0 ; j < actionToken.getCharPositionInLine() ; j++ ) {
ws += " ";
}
text = ws + text;
}
nChunks.addAll(splitLines(text));
}
else {
if ( nChunks.isEmpty() && actionToken.getCharPositionInLine() >= 0 ) {
// first chunk and some 'virtual' WS at beginning
// add as a chunk of its own
String ws = "";
for ( int j = 0 ; j <= actionToken.getCharPositionInLine() ; j++ ) {
ws += " ";
}
nChunks.add(ws);
}
nChunks.add(chunk);
}
}
int lineNo = actionToken.getLine();
int col = 0;
// strip trailing empty lines
int lastChunk = nChunks.size() - 1;
while ( lastChunk > 0
&& nChunks.get(lastChunk) instanceof String
&& ((String)nChunks.get(lastChunk)).trim().length() == 0 )
lastChunk--;
// string leading empty lines
int firstChunk = 0;
while ( firstChunk <= lastChunk
&& nChunks.get(firstChunk) instanceof String
&& ((String)nChunks.get(firstChunk)).trim().length() == 0
&& ((String)nChunks.get(firstChunk)).endsWith("\n") ) {
lineNo++;
firstChunk++;
}
int indent = -1;
for ( int i = firstChunk ; i <= lastChunk ; i++ ) {
Object chunk = nChunks.get(i);
//System.out.println(lineNo + ":" + col + " " + quote(chunk.toString()));
if ( chunk instanceof String ) {
String text = (String)chunk;
if ( col == 0 ) {
if ( indent == -1 ) {
// first non-blank line
// count number of leading whitespaces
indent = 0;
for ( int j = 0; j < text.length(); j++ ) {
if ( !Character.isWhitespace(text.charAt(j)) )
break;
indent++;
}
}
if ( text.length() >= indent ) {
int j;
for ( j = 0; j < indent ; j++ ) {
if ( !Character.isWhitespace(text.charAt(j)) ) {
// should do real error reporting here...
System.err.println("Warning: badly indented line " + lineNo + " in action:");
System.err.println(text);
break;
}
}
nChunks.set(i, text.substring(j));
}
else if ( text.trim().length() > 0 ) {
// should do real error reporting here...
System.err.println("Warning: badly indented line " + lineNo + " in action:");
System.err.println(text);
}
}
if ( text.endsWith("\n") ) {
lineNo++;
col = 0;
}
else {
col += text.length();
}
}
else {
// not really correct, but all I need is col to increment...
col += 1;
}
}
return nChunks;
}
}