parsing: the run-time library for parsers generated by camlyacc
value symbol_start : unit -> int
value symbol_end : unit -> int
symbol_start and symbol_end are to be called in the action part
of a grammar rule only. They return the position of the string that
matches the left-hand side of the rule: symbol_start() returns
the position of the first character; symbol_end() returns the
position of the last character, plus one. The first character
in a file is at position 0.
value rhs_start: int -> int
value rhs_end: int -> int
Same as symbol_start and symbol_end above, but return the
position of the string matching the nth item on the
right-hand side of the rule, where n is the integer parameter
to lhs_start and lhs_end. n is 1 for the leftmost item.
value clear_parser : unit -> unit
Empty the parser stack. Call it just after a parsing function
has returned, to remove all pointers from the parser stack
to structures that were built by semantic actions during parsing.
This is optional, but lowers the memory requirements of the
Raised when a parser encounters a syntax error.