listof : ('a -> 'b * 'c) -> ('c -> 'd * 'a) -> string -> 'a -> 'b list * 'c
Parses a separated list of items.
If p is a parser for ``items'' of some kind, s is a parser for a
``separator'', and e is an error message, then listof p s e parses a
nonempty list of successive items using p, where adjacent items are separated
by something parseable by s. If a separator is parsed successfully but there
is no following item that can be parsed by s, an exception Failure e is
raised. (So note that the separator must not terminate the final element.)
- FAILURE CONDITIONS
The call listof p s e itself never fails, though the resulting parser may.
This is one of a suite of combinators for manipulating ``parsers''. A parser is
simply a function whose OCaml type is some instance of
:('a)list -> 'b * ('a)list. The function should take a list of objects of
type :'a (e.g. characters or tokens), parse as much of it as possible from
left to right, and return a pair consisting of the object derived from parsing
(e.g. a term or a special syntax tree) and the list of elements that were not
- SEE ALSO
++, ||, >>, a, atleast, elistof, finished, fix, leftbin, many, nothing,
possibly, rightbin, some.