[antlr-interest] Tree parser changes Token type?

[Terence Parr]

Howdy.  It looks like you have a problem in the lexer not the parser.  
You probably reference a "Do" somewhere or don't define DO in the lexer.

Terence

On Friday, November 29, 2002, at 04:09  AM, Anakreon Mejdi wrote:

> I observed somthing really strange.
> The parser changes the type of the Token (which I verified with a
> System.out) but when the tree is printed (with ASTVisitor) the Token
> apears to have the original type.
>
> The mail has two attachments.
> The file used for testing and the output of the program.
> Here is the rule for the do statement.
> do_statement
>    { boolean whileFound = false;}
>    :
>    d:DO^
>    (
>    /*
>      The problem is when
>      do while a < 0
>          while z > 3
>            .....
>          wend
>          ...
>      loop
>      can not distinguish betwen do while .. while .. wend loop
>      It should be ok
>     */
>      options {
>          warnWhenFollowAmbig = false;
>      }
>      :
>      STATEMENT_END!
>      | do_while {whileFound = true; d.setType(DO_WHILE);} 
> (STATEMENT_END!)?
>    )?
>    (statements)*
>    LOOP!
>    (
>      {!whileFound}? do_while {d.setType(WHILE_DO);}
>      |
>    )
>    {
>        System.out.println("DO type is:" + d.getType());
>    }
>    ;
>
> If interested in investigating the phainomenon I can send all the 
> gramar.
>
> By.
> Anakreon
>
>
>
> Your use of Yahoo! Groups is subject to 
> http://docs.yahoo.com/info/terms/
>
> Vbs Parser
> DO type is:67
> found obj_member:eof
> found obj_name: rs
> found not
> found obj_member:bof
> found obj_name: rs
> found not
> found and
> found obj_member:Fields
> found obj_member:Count
> found obj_name: rs
> found minus
> found obj_member:Fields
> found obj_member:Name
> found obj_name: rs
> found if and expr and statements
> ANTLR Tree Parsing RecognitionException Error:
> File Name:<AST>
> [-1:-1]
> <AST>: unexpected AST node: Do
> 	at gr.omadak.leviathan.asp.VbsTree.if_statement(VbsTree.java:841)
> 	at gr.omadak.leviathan.asp.VbsTree.statement(VbsTree.java:354)
> 	at gr.omadak.leviathan.asp.VbsTree.statements(VbsTree.java:1999)
> 	at gr.omadak.leviathan.asp.VbsTree.expr_statement(VbsTree.java:1979)
> 	at gr.omadak.leviathan.asp.VbsTree.if_statement(VbsTree.java:797)
> 	at gr.omadak.leviathan.asp.VbsTree.statement(VbsTree.java:354)
> 	at gr.omadak.leviathan.asp.VbsTree.start_rule(VbsTree.java:193)
> 	at Main2.main(Main2.java:33)
>
>
> found if and expr and statements
> found if
> AST
>
>  [73]
> if [23]
>    EXPR [50]
>       iMode [77]
>       = [51]
>       1 [61]
>    if [23]
>       EXPR [50]
>          and [4]
>             not [29]
>                rs [59]
>                   . [63]
>                      eof [60]
>             not [29]
>                rs [59]
>                   . [63]
>                      bof [60]
>       for [21]
>          FOR_INIT [66]
>             = [78]
>                i [77]
>                EXPR [50]
>                   0 [61]
>             to [43]
>                - [90]
>                   rs [59]
>                      . [63]
>                         Fields [60]
>                      . [63]
>                         Count [60]
>                   1 [61]
>          rs [59]
>             . [63]
>                Fields [60]
>                PARAMETERS [56]
>                   EXPR [50]
>                      i [77]
>             . [63]
>                Name [60]
>          next [28]
>       = [78]
>          j [77]
>          0 [61]
>       Do [9]
>          While [46]
>             EXPR [50]
>                Not [29]
>                   rs [59]
>                      . [63]
>                         EOF [60]
>          for [21]
>             FOR_INIT [66]
>                = [78]
>                   i [77]
>                   EXPR [50]
>                      0 [61]
>                to [43]
>                   - [90]
>                      rs [59]
>                         . [63]
>                            Fields [60]
>                         . [63]
>                            Count [60]
>                      1 [61]
>             rs [59]
>                . [63]
>                   Fields [60]
>                   PARAMETERS [56]
>                      EXPR [50]
>                         i [77]
>             next [28]
>          rs [59]
>             . [63]
>                MoveNext [60]
>          = [78]
>             j [77]
>             + [89]
>                j [77]
>                1 [61]
>
>
>  [73]
> <%@Language="VBSCript"%>
> <%
>     if iMode = 1 then
> 			if not rs.eof and not rs.bof then
>         for i=0 to rs.Fields.Count-1
>             rs.Fields(i).Name
>         next
>         j=0
> 				Do While Not rs.EOF
>             for i=0 to rs.Fields.Count-1
>                 rs.Fields(i)
>             next
>             rs.MoveNext()
>             j=j+1
> 				Loop
>       end if
> 		end if
> %>
>
>
--
Co-founder, http://www.jguru.com
Creator, ANTLR Parser Generator: http://www.antlr.org
Lecturer in Comp. Sci., University of San Francisco


 

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