com.google.clearsilver.jsilver.syntax
Class TypeResolver

java.lang.Object
  extended by com.google.clearsilver.jsilver.syntax.analysis.AnalysisAdapter
      extended by com.google.clearsilver.jsilver.syntax.analysis.DepthFirstAdapter
          extended by com.google.clearsilver.jsilver.syntax.TypeResolver
All Implemented Interfaces:
Analysis, Switch

public class TypeResolver
extends DepthFirstAdapter

AST visitor to add numeric expressions to the syntax tree.

There are three types of expression we need to process; addition, equality and inequality. By default these are treated as string expressions unless one of the operands is numeric, in which case the original expression is replaced with its numeric equivalent. This behavior seems to exactly match Clearsilver's type inference system.

Note how we preprocess our node before testing to see is it should be replaced. This is very important because it means that type inference is propagated correctly along compound expressions. Consider the expression:

#a + b + c
which is parsed (left-to-right) as:
(#a + b) + c
When we process the left-hand-side sub-expression #a + b it is turned into a numeric addition (due to the forced numeric value on the left). Then when we process the main expression we propagate the numeric type into it.

This matches Clearsilver behavior but means that the expressions:

#a + b + c
and
c + b + #a
produce different results (the c + b subexpression in the latter is evaluated as string concatenation and not numeric addition).


Constructor Summary
TypeResolver()
           
 
Method Summary
 void caseAAddExpression(AAddExpression node)
           
 void caseAEqExpression(AEqExpression node)
           
 void caseANeExpression(ANeExpression node)
           
 
Methods inherited from class com.google.clearsilver.jsilver.syntax.analysis.DepthFirstAdapter
caseAAltCommand, caseAAndExpression, caseAAutoescapeCommand, caseACallCommand, caseACommaExpression, caseACommentCommand, caseAContentTypeCommand, caseACsOpenPosition, caseADataCommand, caseADecimalExpression, caseADecNumberVariable, caseADefCommand, caseADescendVariable, caseADivideExpression, caseAEachCommand, caseAEscapeCommand, caseAEvarCommand, caseAExistsExpression, caseAExpandVariable, caseAFunctionExpression, caseAGteExpression, caseAGtExpression, caseAHardIncludeCommand, caseAHardLincludeCommand, caseAHexExpression, caseAHexNumberVariable, caseAIfCommand, caseAIncludeCommand, caseAInlineCommand, caseALincludeCommand, caseALoopCommand, caseALoopIncCommand, caseALoopToCommand, caseALteExpression, caseALtExpression, caseALvarCommand, caseAModuloExpression, caseAMultipleCommand, caseAMultiplyExpression, caseANameCommand, caseANameVariable, caseANegativeExpression, caseANoopCommand, caseANoopExpression, caseANotExpression, caseANumericAddExpression, caseANumericEqExpression, caseANumericExpression, caseANumericNeExpression, caseAOrExpression, caseASequenceExpression, caseASetCommand, caseAStringExpression, caseASubtractExpression, caseAUvarCommand, caseAVarCommand, caseAVariableExpression, caseAWithCommand, caseStart, defaultIn, defaultOut, inAAddExpression, inAAltCommand, inAAndExpression, inAAutoescapeCommand, inACallCommand, inACommaExpression, inACommentCommand, inAContentTypeCommand, inACsOpenPosition, inADataCommand, inADecimalExpression, inADecNumberVariable, inADefCommand, inADescendVariable, inADivideExpression, inAEachCommand, inAEqExpression, inAEscapeCommand, inAEvarCommand, inAExistsExpression, inAExpandVariable, inAFunctionExpression, inAGteExpression, inAGtExpression, inAHardIncludeCommand, inAHardLincludeCommand, inAHexExpression, inAHexNumberVariable, inAIfCommand, inAIncludeCommand, inAInlineCommand, inALincludeCommand, inALoopCommand, inALoopIncCommand, inALoopToCommand, inALteExpression, inALtExpression, inALvarCommand, inAModuloExpression, inAMultipleCommand, inAMultiplyExpression, inANameCommand, inANameVariable, inANeExpression, inANegativeExpression, inANoopCommand, inANoopExpression, inANotExpression, inANumericAddExpression, inANumericEqExpression, inANumericExpression, inANumericNeExpression, inAOrExpression, inASequenceExpression, inASetCommand, inAStringExpression, inASubtractExpression, inAUvarCommand, inAVarCommand, inAVariableExpression, inAWithCommand, inStart, outAAddExpression, outAAltCommand, outAAndExpression, outAAutoescapeCommand, outACallCommand, outACommaExpression, outACommentCommand, outAContentTypeCommand, outACsOpenPosition, outADataCommand, outADecimalExpression, outADecNumberVariable, outADefCommand, outADescendVariable, outADivideExpression, outAEachCommand, outAEqExpression, outAEscapeCommand, outAEvarCommand, outAExistsExpression, outAExpandVariable, outAFunctionExpression, outAGteExpression, outAGtExpression, outAHardIncludeCommand, outAHardLincludeCommand, outAHexExpression, outAHexNumberVariable, outAIfCommand, outAIncludeCommand, outAInlineCommand, outALincludeCommand, outALoopCommand, outALoopIncCommand, outALoopToCommand, outALteExpression, outALtExpression, outALvarCommand, outAModuloExpression, outAMultipleCommand, outAMultiplyExpression, outANameCommand, outANameVariable, outANeExpression, outANegativeExpression, outANoopCommand, outANoopExpression, outANotExpression, outANumericAddExpression, outANumericEqExpression, outANumericExpression, outANumericNeExpression, outAOrExpression, outASequenceExpression, outASetCommand, outAStringExpression, outASubtractExpression, outAUvarCommand, outAVarCommand, outAVariableExpression, outAWithCommand, outStart
 
Methods inherited from class com.google.clearsilver.jsilver.syntax.analysis.AnalysisAdapter
caseEOF, caseTAlt, caseTAnd, caseTArgWhitespace, caseTAssignment, caseTAutoescape, caseTBang, caseTBracketClose, caseTBracketOpen, caseTCall, caseTComma, caseTCommandDelimiter, caseTComment, caseTCommentStart, caseTContentType, caseTCsClose, caseTCsOpen, caseTData, caseTDecNumber, caseTDef, caseTDollar, caseTDot, caseTEach, caseTElse, caseTElseIf, caseTEq, caseTEscape, caseTEvar, caseTGt, caseTGte, caseTHardDelimiter, caseTHash, caseTHexNumber, caseTIf, caseTInclude, caseTInline, caseTLinclude, caseTLoop, caseTLt, caseTLte, caseTLvar, caseTMinus, caseTName, caseTNe, caseTOr, caseTParenClose, caseTParenOpen, caseTPercent, caseTPlus, caseTQuestion, caseTSet, caseTSlash, caseTStar, caseTString, caseTUvar, caseTVar, caseTWith, caseTWord, defaultCase, getIn, getOut, setIn, setOut
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

TypeResolver

public TypeResolver()
Method Detail

caseAAddExpression

public void caseAAddExpression(AAddExpression node)
Specified by:
caseAAddExpression in interface Analysis
Overrides:
caseAAddExpression in class DepthFirstAdapter

caseAEqExpression

public void caseAEqExpression(AEqExpression node)
Specified by:
caseAEqExpression in interface Analysis
Overrides:
caseAEqExpression in class DepthFirstAdapter

caseANeExpression

public void caseANeExpression(ANeExpression node)
Specified by:
caseANeExpression in interface Analysis
Overrides:
caseANeExpression in class DepthFirstAdapter


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