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With inspiration from other libraries
/*
* [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.
*/
/** Build an AST from a single StringTemplate template */
parser grammar STParser;
options {
language=Java;
tokenVocab=STLexer;
TokenLabelType=CommonToken;
output=AST;
ASTLabelType=CommonTree;
}
tokens {
EXPR; OPTIONS; PROP; PROP_IND; INCLUDE; INCLUDE_IND; EXEC_FUNC; INCLUDE_SUPER;
INCLUDE_SUPER_REGION; INCLUDE_REGION; TO_STR; LIST; MAP; ZIP; SUBTEMPLATE; ARGS;
ELEMENTS; REGION; NULL; INDENTED_EXPR;
}
@header {
package org.stringtemplate.v4.compiler;
import org.stringtemplate.v4.misc.ErrorManager;
import org.stringtemplate.v4.misc.ErrorType;
}
@members {
ErrorManager errMgr;
Token templateToken;
public STParser(TokenStream input, ErrorManager errMgr, Token templateToken) {
this(input);
this.errMgr = errMgr;
this.templateToken = templateToken;
}
@Override
protected Object recoverFromMismatchedToken(IntStream input, int ttype, BitSet follow)
throws RecognitionException
{
throw new MismatchedTokenException(ttype, input);
}
}
@rulecatch {
catch (RecognitionException re) { throw re; }
}
templateAndEOF : template EOF -> template? ;
template : element* ;
element
: {input.LT(1).getCharPositionInLine()==0}? INDENT? COMMENT NEWLINE -> // throw away
| INDENT singleElement -> ^(INDENTED_EXPR INDENT singleElement?) // singleElement is optional to handle error returning nil
| singleElement
| compoundElement
;
singleElement
: exprTag
| TEXT
| NEWLINE
| COMMENT! // throw away
;
compoundElement
: ifstat
| region
;
exprTag
: LDELIM expr ( ';' exprOptions )? RDELIM
-> ^(EXPR[$LDELIM,"EXPR"] expr exprOptions?)
;
region
@init {Token indent=null;}
: i=INDENT? x=LDELIM '@' ID RDELIM {if (input.LA(1)!=NEWLINE) indent=$i;}
template
INDENT? LDELIM '@end' RDELIM
// kill \n for <@end> on line by itself if multi-line embedded region
({$region.start.getLine()!=input.LT(1).getLine()}?=> NEWLINE)?
-> {indent!=null}?
^(INDENTED_EXPR $i ^(REGION[$x] ID template?))
-> ^(REGION[$x] ID template?)
;
subtemplate
: lc='{' (ids+= ID ( ',' ids+= ID )* '|' )? template INDENT? '}'
// ignore final INDENT before } as it's not part of outer indent
-> ^(SUBTEMPLATE[$lc,"SUBTEMPLATE"] ^(ARGS $ids)* template?)
;
ifstat
@init {Token indent=null;}
: i=INDENT? LDELIM 'if' '(' c1=conditional ')' RDELIM {if (input.LA(1)!=NEWLINE) indent=$i;}
t1=template
( INDENT? LDELIM 'elseif' '(' c2+=conditional ')' RDELIM t2+=template )*
( INDENT? LDELIM 'else' RDELIM t3=template )?
INDENT? endif= LDELIM 'endif'
RDELIM
// kill \n for on line by itself if multi-line IF
({$ifstat.start.getLine()!=input.LT(1).getLine()}?=> NEWLINE)?
-> {indent!=null}?
^(INDENTED_EXPR $i ^('if' $c1 $t1? ^('elseif' $c2 $t2)* ^('else' $t3?)?))
-> ^('if' $c1 $t1? ^('elseif' $c2 $t2)* ^('else' $t3?)?)
;
conditional
scope {
boolean inside;
}
: andConditional ( '||'^ andConditional )*
;
andConditional : notConditional ( '&&'^ notConditional )* ;
notConditional
: '!'^ notConditional
| memberExpr
;
notConditionalExpr
: (ID->ID)
( p='.' prop=ID -> ^(PROP[$p,"PROP"] $notConditionalExpr $prop)
| p='.' '(' mapExpr ')' -> ^(PROP_IND[$p,"PROP_IND"] $notConditionalExpr mapExpr)
)*
;
exprOptions : option ( ',' option )* -> ^(OPTIONS option*) ;
option
@init {
String id = input.LT(1).getText();
String defVal = Compiler.defaultOptionValues.get(id);
boolean validOption = Compiler.supportedOptions.get(id)!=null;
}
: ID
{
if ( !validOption ) {
errMgr.compileTimeError(ErrorType.NO_SUCH_OPTION, templateToken, $ID, $ID.text);
}
}
( '=' exprNoComma -> {validOption}? ^('=' ID exprNoComma)
->
| {
if ( defVal==null ) {
errMgr.compileTimeError(ErrorType.NO_DEFAULT_VALUE, templateToken, $ID);
}
}
-> {validOption&&defVal!=null}?
^(EQUALS["="] ID STRING[$ID,'"'+defVal+'"'])
->
)
;
exprNoComma
: memberExpr
( ':' mapTemplateRef -> ^(MAP memberExpr mapTemplateRef)
| -> memberExpr
)
;
expr : mapExpr ;
// more complicated than necessary to avoid backtracking, which ruins
// error handling
mapExpr
: memberExpr
( (c=',' memberExpr)+ col=':' mapTemplateRef
-> ^(ZIP[$col] ^(ELEMENTS memberExpr+) mapTemplateRef)
| -> memberExpr
)
( {if ($x!=null) $x.clear();} // don't keep queueing x; new list for each iteration
col=':' x+=mapTemplateRef ({$c==null}?=> ',' x+=mapTemplateRef )*
-> ^(MAP[$col] $mapExpr $x+)
)*
;
/**
expr:template(args) apply template to expr
expr:{arg | ...} apply subtemplate to expr
expr:(e)(args) convert e to a string template name and apply to expr
*/
mapTemplateRef
: qualifiedId '(' args ')' -> ^(INCLUDE qualifiedId args?)
| subtemplate
| lp='(' mapExpr rp=')' '(' argExprList? ')' -> ^(INCLUDE_IND mapExpr argExprList?)
;
memberExpr
: (includeExpr->includeExpr)
( p='.' ID -> ^(PROP[$p,"PROP"] $memberExpr ID)
| p='.' '(' mapExpr ')' -> ^(PROP_IND[$p,"PROP_IND"] $memberExpr mapExpr)
)*
;
includeExpr
options {k=2;} // prevent full LL(*), which fails, falling back on k=1; need k=2
: {Compiler.funcs.containsKey(input.LT(1).getText())}? // predefined function
ID '(' expr? ')' -> ^(EXEC_FUNC ID expr?)
| 'super' '.' ID '(' args ')' -> ^(INCLUDE_SUPER ID args?)
| qualifiedId '(' args ')' -> ^(INCLUDE qualifiedId args?)
| '@' 'super' '.' ID '(' rp=')' -> ^(INCLUDE_SUPER_REGION ID)
| '@' ID '(' rp=')' -> ^(INCLUDE_REGION ID)
| primary
;
primary
: ID
| STRING
| TRUE
| FALSE
| subtemplate
| list
| {$conditional.size()>0}?=> '('! conditional ')'!
| {$conditional.size()==0}?=> lp='(' expr ')'
( '(' argExprList? ')' -> ^(INCLUDE_IND[$lp] expr argExprList?)
| -> ^(TO_STR[$lp] expr)
)
;
qualifiedId
: ( ID -> ID
| '/' ID -> ^('/' ID)
)
( '/' r=ID -> ^('/' $qualifiedId $r)
)*
;
args: argExprList
| namedArg ( ',' namedArg )* (',' '...')? -> namedArg+ '...'?
| '...'
|
;
argExprList : arg ( ',' arg )* -> arg+ ;
arg : exprNoComma ;
namedArg : ID '=' arg -> ^('=' ID arg) ;
list: {input.LA(2)==RBRACK}? // hush warning; [] special case
lb='[' ']' -> LIST[$lb]
| lb='[' listElement ( ',' listElement )* ']' -> ^(LIST[$lb] listElement*)
;
listElement : exprNoComma | -> NULL ;