[antlr-interest] Tree grammar doesn't match what I want

[Andrew House]

Thanks for this tip.  Using the trace option showed me the problem was 
not with my array data type, but actually with my expression matching 
rule.  (I had made a stupid mistake in my expression tree matcher.)

-- Andrew House

On 06/10/2012 6:07 PM, Juancarlo Añez wrote:
> You can use the '-trace' option to see where exactly the parser is 
> failing. An "upper" rule will fail if one on which it depends fails.
>
> -- Juancarlo
>
> On Sat, Oct 6, 2012 at 2:56 PM, Andrew House <ahouse at eecg.toronto.edu 
> <mailto:ahouse at eecg.toronto.edu>> wrote:
>
>
>     Hi all,
>
>     I am working on my own language application, and am following the
>     Language Implementation Patterns and Definitive ANTLR Reference
>     books as
>     closely as I can.  I have run into an issue where my tree grammar
>     seems
>     unable to match my 'array' subtree (representing an array data type).
>
>     An example of what fails to match is as follows:
>     (array (SIZE (EXPR (to 1 (IDX N)))) (SCALAR (NAME (TYPEID Particle))))
>
>     Below, I have included relevant snippets of the grammar and tree
>     grammar.  The tree grammar has no trouble recognizing the 'tuple' and
>     'scalar' data type subtrees.
>
>     I know that the grammar allows for arrays of arrays (of arrays...)
>     if I
>     were so inclined, but I don't think that's the culprit.  As far as
>     I can
>     tell the grammar is unambiguous.  It just doesn't seem to match
>     for arrays.
>
>     Any help would be greatly appreciated---I've been looking at this for
>     several days now, and haven't managed to see the problem.
>
>     Sincerely,
>     -- Andrew House
>
>     Grammar ======================================================
>
>     varDeclaration
>          :    'var' ID 'is' dataType ';'
>              -> ^('var' ^(NAME ID) ^(VARTYPE dataType) )
>          ;
>
>     dataType
>          :    dataTypeID sizeDef?-> ^(SCALAR ^(NAME dataTypeID) sizeDef? )
>          |    'array' arrayDims 'of' dataType -> ^('array' arrayDims
>     dataType )
>          |    'tuple' '(' argList ')' -> ^('tuple' argList)
>          ;
>
>     argList
>          :    argDeclaration (',' argDeclaration)* -> argDeclaration+
>          ;
>
>     argDeclaration
>          :    dataType ID -> ^(ARG ^(NAME ID) ^(VARTYPE dataType))
>          ;
>
>     arrayDims
>          :    sizeDef | regionDef
>          ;
>
>     dataTypeID
>          :    ID ('.' ID)* -> ^(TYPEID ID+)
>          ;
>
>     dataTypeList
>          :    dataType (',' dataType)* -> dataType+
>          ;
>
>     sizeDef
>          :    '[' expr ']' -> ^(SIZE expr)
>          ;
>
>     regionDef
>          :    '[' idList 'in' expr ']' -> ^(REGION expr idList)
>          ;
>
>     Tree Grammar
>     ====================================================================
>
>     varDeclaration
>          :    ^('var' ^(NAME ID) ^(VARTYPE dt=dataType) .*)
>              {
>                  // Code to resolve data type
>              }
>          ;
>
>
>     dataType returns [ASymbol type, AIndexRange size] // updated for
>     resolution
>          :    (tsid=scalarDataType | taid=arrayDataType |
>     ttid=tupleDataType )
>              {
>                  // Code to determine whether it is tuple, scalar, or
>     array
>     type,
>            // and pass up appropriate values.
>              }
>          ;
>
>     scalarDataType returns [ASymbol type, AIndexRange size]
>          :    ^(SCALAR ^(NAME ^(TYPEID name+=ID+)) sz=sizeDef?)
>              {
>                  // Resolve scalar data types
>              }
>          ;
>
>     arrayDataType returns [ASymbol type, AIndexRange size]
>          :    ^(aid='array' dim=arrayDims dt=dataType)
>              {
>                // Resolve array dimensions and subtype
>            // THIS NEVER SEEMS TO MATCH ANYTHING!!!!!!
>                 // A print statement in here never executes.
>              }
>          ;
>
>     tupleDataType returns [ASymbol type, AIndexRange size]
>          :    ^(tid='tuple' .*)
>              {
>                  // Returns appropriate tuple values
>              }
>          ;
>
>     arrayDims returns [AIndexRegion region]
>          :    sz=sizeDef | rg=regionDef
>              {
>                  // Figures out if it is a size or region
>            // and returns a region.
>              }
>          ;
>
>     sizeDef returns [AIndexRange range]
>          :    ^(SIZE ex=exprRoot)
>          ;
>
>     regionDef returns [AIndexRegion region]
>          :    ^(REGION ex=exprRoot ids+=ID+)
>          ;
>
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>
>
> -- 
> Juancarlo *Añez*