docs

C/parser.c

@@ -18,121 +18,6 @@
 static char SccsId[] = "%W% %G%";
 #endif
 
-/**
-
-@addtogroup YAPSyntax
-
-describe the syntax for Prolog terms. In a second level we describe
-the \a tokens from which Prolog \a terms are
-built.
-
-@defgroup Formal_Syntax Syntax of Terms
-@ingroup YAPSyntax
-@{
-
-Below, we describe the syntax of YAP terms from the different
-classes of tokens defined above. The formalism used will be <em>BNF</em>,
-extended where necessary with attributes denoting integer precedence or
-operator type.
-
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-                                                                  term
----->     subterm(1200)   end_of_term_marker
-
- subterm(N) ---->     term(M)         [M <= N]
-
- term(N)    ---->     op(N, fx) subterm(N-1)
-             |        op(N, fy) subterm(N)
-             |        subterm(N-1) op(N, xfx) subterm(N-1)
-             |        subterm(N-1) op(N, xfy) subterm(N)
-             |        subterm(N) op(N, yfx) subterm(N-1)
-             |        subterm(N-1) op(N, xf)
-             |        subterm(N) op(N, yf)
-
- term(0)   ---->      atom '(' arguments ')'
-             |        '(' subterm(1200)  ')'
-             |        '{' subterm(1200)  '}'
-             |        list
-             |        string
-             |        number
-             |        atom
-             |        variable
-
- arguments ---->      subterm(999)
-             |        subterm(999) ',' arguments
-
- list      ---->      '[]'
-             |        '[' list_expr ']'
-
- list_expr ---->      subterm(999)
-             |        subterm(999) list_tail
-
- list_tail ---->      ',' list_expr
-             |        ',..' subterm(999)
-             |        '|' subterm(999)
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-Notes:
-
-   + \a op(N,T) denotes an atom which has been previously declared with type
-      \a T and base precedence \a N.
-
-  + Since ',' is itself a pre-declared operator with type \a xfy and
-       precedence 1000, is \a subterm starts with a '(', \a op must be
-       followed by a space to avoid ambiguity with the case of a functor
-       followed by arguments, e.g.:
-
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-+ (a,b)        [the same as '+'(','(a,b)) of arity one]
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-      versus
-
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-+(a,b)         [the same as '+'(a,b) of arity two]
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-  +
-In the first rule for term(0) no blank space should exist between
-\a atom and '('.
-
-  +
-Each term to be read by the YAP parser must end with a single
-dot, followed by a blank (in the sense mentioned in the previous
-paragraph). When a name consisting of a single dot could be taken for
-the end of term marker, the ambiguity should be avoided by surrounding the
-dot with single quotes.
-
-@}
-
-*/
-
-/*
- * Description:
- *
- * parser:     produces a prolog term from an array of tokens
- *
- * parser usage: the parser takes its input from an array of token descriptions
- * addressed by the global variable 'tokptr' and produces a Term as result. A
- * macro 'NextToken' should be defined in 'yap.h' for advancing 'tokptr' from
- * one token to the next. In the distributed version this macro also updates
- * a variable named 'toktide' for keeping track of how far the parser went
- * before failling with a syntax error. The parser should be invoked with
- * 'tokptr' pointing to the first token. The last token should have type
- * 'eot_tok'. The parser return either a Term. Syntactic errors are signaled
- * by a return value 0. The parser builds new terms on the 'global stack' and
- * also uses an auxiliary stack pointed to by 'AuxSp'. In the distributed
- * version this auxiliary stack is assumed to grow downwards. This
- * assumption, however, is only relevant to routine 'ParseArgs', and to the
- * variable toktide. conclusion: set tokptr pointing to first token set AuxSp
- * Call Parse
- *
- * VSC: Working whithout known bugs in 87/4/6
- *
- * LD: -I or +I evaluated by parser 87/4/28
- *
- * LD: parser extended 87/4/28
- *
- */
 
 #include "Yap.h"
 #include "YapEval.h"