83 lines
2.9 KiB
Plaintext
83 lines
2.9 KiB
Plaintext
/*
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[The "BSD license"]
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Copyright (c) 2010 Terence Parr
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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1. Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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3. The name of the author may not be used to endorse or promote products
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derived from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/** How to generate rules derived from left-recursive rules.
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* These rely on recRuleDefArg(), recRuleAltPredicate(),
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* recRuleArg(), recRuleSetResultAction(), recRuleSetReturnAction()
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* templates in main language.stg
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*/
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group LeftRecursiveRules;
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recRuleName(ruleName) ::= "<ruleName>_"
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recPrimaryName(ruleName) ::= "<ruleName>_primary"
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recRuleStart(ruleName, minPrec, userRetvals, userRetvalAssignments) ::= <<
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<ruleName><if(userRetvals)> returns [<userRetvals>]<endif>
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: <recRuleName(...)>[<minPrec>]
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<if(userRetvals)>
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{
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<userRetvalAssignments; separator="\n">
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}
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<endif>
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;
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>>
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recRule(ruleName, precArgDef, argName, alts, setResultAction, buildAST,
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userRetvals, userRetvalAssignments) ::= <<
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<recRuleName(...)>[<precArgDef>]<if(userRetvals)> returns [<userRetvals>]<endif>
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: <recPrimaryName(...)>
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<if(buildAST)>
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{
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<setResultAction>
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}
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<endif>
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<if(userRetvals)>
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{
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<userRetvalAssignments; separator="\n">
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}
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<endif>
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( options {backtrack=false;}
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: ( options {backtrack=false;}
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: <alts; separator="\n | ">
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)
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)*
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;
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>>
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recPrimaryRule(ruleName, alts, userRetvals) ::= <<
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<recPrimaryName(...)><if(userRetvals)> returns [<userRetvals>]<endif>
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options {backtrack=true;}
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: <alts; separator="\n | ">
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;
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>>
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recRuleAlt(alt, pred) ::= "{<pred>}?=> <alt>"
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recRuleRef(ruleName, arg) ::= "<recRuleName(...)>[<arg>]"
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