[antlr-interest] Question on recognizing a pattern

[Brian Smith]

parser rules must start with a lowercase letter.
lexer  rules must start with an uppercase letter.

ANTLR assumes that, because all your rules start with an uppercase 
letter, they are meant to be lexer rules.

- Brian

byeung128 wrote:
> I am just a beginner on Antlr and I really think it is a gift for any 
> developers. After reading some examples, I am trying to write a 
> parser to recognize a address pattern like "NUMBER STREETNAME 
> STREETTYPE DIRECTION". When I compiled the following source, I got 
> error messages like "Lexical rule STREETYPE defined outside of 
> lexer...". However, I declare all these rules inside the parser 
> section not lexer section. Could you tell me what goes wrong ? Could 
> you give me some advice on this grammar ? Thanks in advance.
> 
> class MyParser extends Parser;
> {
>   int i_count = 0 ;
> }
> 
> startRule: a:address
>    { System.out.println ( "->>>>>ADDRESS:" + a.getText() ); };
> 
> 
> address : NUMBER STREETNAME STREETTYPE DIRECTION   ;
> 
> STREETTYPE:  AVENUE 
>           |  STREET
>           ;
> 
> AVENUE: "AVENUE" 
>       | "AVENUE."
>       | "AV"
>       | "AV."
>       | "AVE"
>       | "AVE."
>       ;
> 
> STREET: "STREET"
>       | "STR"
>       | "STR."
>       | "ST."
>       | "ST"
>       ;
> 
> DIRECTION: EAST
>          | WEST
>          | SOUTH
>          | NORTH
>          | NORTHWEST
>          | SOUTHWEST
>          | NORTHEAST
>          | SOUTHEAST
>          ;
> 
> EAST: "EAST"
>     | "E."
>     | "E"
>     ;
> 
> WEST: "WEST"
>     | "W."
>     | "W"
>     ;
> 
> NORTH: "NORTH"
>      | "N."
>      | "N"
>      ;
> 
> SOUTH: "SOUTH"
>      | "S."
>      | "S"
>      ;
>      
> NORTHWEST: "NORTHWEST"
>          | "NW."
>          | "NW"
>          ;
> 
> NORTHEAST: "NORTHEAST"
>          | "NE."
>          | "NE"
>          ;
> 
> SOUTHWEST: "SOUTHWEST"
>          | "SW."
>          | "SW"
>          ;
>    
> SOUTHEAST: "SOUTHEAST"
>          | "SE."
>          | "SE"
>          ;
> 
> class MyLexer extends Lexer;
> options {
>   charVocabulary = '\3'..'\377' ;
>   testLiterals=false ;
>   k = 2 ;
> }
> 
> {
>   int i_STREETNAMECount = 0;
>   int i_DICount = 0;
>   int i_WSCount = 0;
> }
> 
> WS : ( ' ' | '\t' | '\n' | '\r' ) 
>      { $setType(Token.SKIP) ; 
>        System.out.println ( "WS:" + (++i_WSCount) );  } ;
> 
> STREETNAME  
>   options { testLiterals = true ; } 
> : ( 'a'..'z' | 'A'..'Z' )+ 
>   { System.out.println ( "CSTREETNAME:" + $getText ) ; 
>     System.out.println ( "STREETNAME:" + (++i_STREETNAMECount) ); } ;
> 
> NUMBER: ( '0'..'9' )+ 
>      { System.out.println ( "CNUMBER:" + $getText ) ; 
>        System.out.println ( "NUMBER:" + (++i_DICount) ); } ;
> 
> 
>  
> 
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