Info Catalog bovine: How Lexical Tokens Match bovine: Bovine Grammar Rules bovine: Order of components in rules

bovine: Grammar-to-Lisp Details

 
 2.2 Grammar-to-Lisp Details
 ===========================
 
 For the bovinator, lexical token matching patterns are _inlined_.  When
 the grammar-to-lisp converter encounters a lexical token declaration of
 the form:
 
      %token <TYPE> TOKEN-NAME MATCH-VALUE
 
    It substitutes every occurrences of TOKEN-NAME in rules, by its
 expanded form:
 
      TYPE MATCH-VALUE
 
    For example:
 
      %token <symbol> MOOSE "moose"
 
      find_a_moose: MOOSE
                  ;
 
    Will generate this pseudo equivalent-rule:
 
      find_a_moose: symbol "moose"   ;; invalid syntax!
                  ;
 
    Thus, from the bovinator point of view, the COMPONENTS part of a rule
 is made up of symbols and strings.  A string in the mix means that the
 previous symbol must have the additional constraint of exactly matching
 it, as described in How Lexical Tokens Match.
 
 *Please Note:*
      For the bovinator, this task was mixed into the language definition
      to simplify implementation, though Bison’s technique is more
      efficient.
 

Info Catalog bovine: How Lexical Tokens Match bovine: Bovine Grammar Rules bovine: Order of components in rules