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StringTemplate is a java template engine for generating source code,
web pages, emails, or any other formatted text output.
StringTemplate is particularly good at multi-targeted code generators,
multiple site skins, and internationalization/localization.
It evolved over years of effort developing jGuru.com.
StringTemplate also powers the ANTLR 3 and 4 code generator. Its distinguishing characteristic
is that unlike other engines, it strictly enforces model-view separation.
Strict separation makes websites and code generators more flexible
and maintainable; it also provides an excellent defense against malicious
template authors.
/*
* [The "BSD license"]
* Copyright (c) 2011 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.
*/
package org.stringtemplate.v4.compiler;
import org.antlr.runtime.*;
import org.antlr.runtime.tree.CommonTree;
import org.antlr.runtime.tree.CommonTreeNodeStream;
import org.stringtemplate.v4.Interpreter;
import org.stringtemplate.v4.ST;
import org.stringtemplate.v4.STGroup;
import org.stringtemplate.v4.misc.ErrorType;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/** A compiler for a single template. */
public class Compiler {
public static final String SUBTEMPLATE_PREFIX = "_sub";
public static final int TEMPLATE_INITIAL_CODE_SIZE = 15;
public static final Map supportedOptions =
new HashMap() {
{
put("anchor", Interpreter.Option.ANCHOR);
put("format", Interpreter.Option.FORMAT);
put("null", Interpreter.Option.NULL);
put("separator", Interpreter.Option.SEPARATOR);
put("wrap", Interpreter.Option.WRAP);
}
};
public static final int NUM_OPTIONS = supportedOptions.size();
public static final Map defaultOptionValues =
new HashMap() {
{
put("anchor", "true");
put("wrap", "\n");
}
};
public static Map funcs = new HashMap() {
{
put("first", Bytecode.INSTR_FIRST);
put("last", Bytecode.INSTR_LAST);
put("rest", Bytecode.INSTR_REST);
put("trunc", Bytecode.INSTR_TRUNC);
put("strip", Bytecode.INSTR_STRIP);
put("trim", Bytecode.INSTR_TRIM);
put("length", Bytecode.INSTR_LENGTH);
put("strlen", Bytecode.INSTR_STRLEN);
put("reverse", Bytecode.INSTR_REVERSE);
}
};
/** Name subtemplates _sub1, _sub2, ... */
public static int subtemplateCount = 0;
public STGroup group;
public Compiler() { this(STGroup.defaultGroup); }
public Compiler(STGroup group) { this.group = group; }
public CompiledST compile(String template) {
CompiledST code = compile(null, null, null, template, null);
code.hasFormalArgs = false;
return code;
}
/** Compile full template with unknown formal args. */
public CompiledST compile(String name, String template) {
CompiledST code = compile(null, name, null, template, null);
code.hasFormalArgs = false;
return code;
}
/** Compile full template with respect to a list of formal args. */
public CompiledST compile(String srcName,
String name,
List args,
String template,
Token templateToken)
{
ANTLRStringStream is = new ANTLRStringStream(template);
is.name = srcName!=null ? srcName : name;
STLexer lexer = null;
if ( templateToken!=null &&
templateToken.getType() == GroupParser.BIGSTRING_NO_NL )
{
lexer = new STLexer(group.errMgr, is, templateToken,
group.delimiterStartChar, group.delimiterStopChar) {
/** Throw out \n and indentation tokens inside BIGSTRING_NO_NL */
@Override
public Token nextToken() {
Token t = super.nextToken();
while ( t.getType() == STLexer.NEWLINE ||
t.getType()==STLexer.INDENT )
{
t = super.nextToken();
}
return t;
}
};
}
else {
lexer = new STLexer(group.errMgr, is, templateToken,
group.delimiterStartChar, group.delimiterStopChar);
}
CommonTokenStream tokens = new CommonTokenStream(lexer);
STParser p = new STParser(tokens, group.errMgr, templateToken);
STParser.templateAndEOF_return r = null;
try {
r = p.templateAndEOF();
}
catch (RecognitionException re) {
reportMessageAndThrowSTException(tokens, templateToken, p, re);
return null;
}
if ( p.getNumberOfSyntaxErrors()>0 || r.getTree()==null ) {
CompiledST impl = new CompiledST();
impl.defineFormalArgs(args);
return impl;
}
//System.out.println(((CommonTree)r.getTree()).toStringTree());
CommonTreeNodeStream nodes = new CommonTreeNodeStream(r.getTree());
nodes.setTokenStream(tokens);
CodeGenerator gen = new CodeGenerator(nodes, group.errMgr, name, template, templateToken);
CompiledST impl=null;
try {
impl = gen.template(name,args);
impl.nativeGroup = group;
impl.template = template;
impl.ast = (CommonTree)r.getTree();
impl.ast.setUnknownTokenBoundaries();
impl.tokens = tokens;
}
catch (RecognitionException re) {
group.errMgr.internalError(null, "bad tree structure", re);
}
return impl;
}
public static CompiledST defineBlankRegion(CompiledST outermostImpl, Token nameToken) {
String outermostTemplateName = outermostImpl.name;
String mangled = STGroup.getMangledRegionName(outermostTemplateName, nameToken.getText());
CompiledST blank = new CompiledST();
blank.isRegion = true;
blank.templateDefStartToken = nameToken;
blank.regionDefType = ST.RegionType.IMPLICIT;
blank.name = mangled;
outermostImpl.addImplicitlyDefinedTemplate(blank);
return blank;
}
public static String getNewSubtemplateName() {
subtemplateCount++;
return SUBTEMPLATE_PREFIX+subtemplateCount;
}
protected void reportMessageAndThrowSTException(TokenStream tokens, Token templateToken,
Parser parser, RecognitionException re)
{
if ( re.token.getType() == STLexer.EOF_TYPE ) {
String msg = "premature EOF";
group.errMgr.compileTimeError(ErrorType.SYNTAX_ERROR, templateToken, re.token, msg);
}
else if ( re instanceof NoViableAltException) {
String msg = "'"+re.token.getText()+"' came as a complete surprise to me";
group.errMgr.compileTimeError(ErrorType.SYNTAX_ERROR, templateToken, re.token, msg);
}
else if ( tokens.index() == 0 ) { // couldn't parse anything
String msg = "this doesn't look like a template: \""+tokens+"\"";
group.errMgr.compileTimeError(ErrorType.SYNTAX_ERROR, templateToken, re.token, msg);
}
else if ( tokens.LA(1) == STLexer.LDELIM ) { // couldn't parse expr
String msg = "doesn't look like an expression";
group.errMgr.compileTimeError(ErrorType.SYNTAX_ERROR, templateToken, re.token, msg);
}
else {
String msg = parser.getErrorMessage(re, parser.getTokenNames());
group.errMgr.compileTimeError(ErrorType.SYNTAX_ERROR, templateToken, re.token, msg);
}
throw new STException(); // we have reported the error, so just blast out
}
}