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Module CCParse

module CCParse: sig .. end

Very Simple Parser Combinators

      open CCParse;;

      type tree = L of int | N of tree * tree;;

      let mk_leaf x = L x
      let mk_node x y = N(x,y)

      let ptree = fix @@ fun self ->
        skip_space *>
          ( (try_ (char '(') *> (pure mk_node <*> self <*> self) <* char ')')
            <|>
              (U.int >|= mk_leaf) )
      ;;

      parse_string_exn ptree "(1 (2 3))" ;;
      parse_string_exn ptree "((1 2) (3 (4 5)))" ;;

    

Parse a list of words

      open Containers.Parse;;
      let p = U.list ~sep:"," U.word;;
      parse_string_exn p "[abc , de, hello ,world  ]";;
    

Stress Test
This makes a list of 100_000 integers, prints it and parses it back. 

      let p = CCParse.(U.list ~sep:"," U.int);;

      let l = CCList.(1 -- 100_000);;
      let l_printed =
        CCFormat.(to_string (within "[" "]" (list ~sep:(return ",@,") int))) l;;

      let l' = CCParse.parse_string_exn p l_printed;;

      assert (l=l');;
    

type 'a or_error = ('a, string) Result.result 
type line_num = int 
type col_num = int 
type parse_branch 
val string_of_branch : parse_branch -> string
exception ParseError of parse_branch * (unit -> string)
parsing branch * message

Input


type position 
type state 
val state_of_string : string -> state

Combinators


type 'a t = state -> ok:('a -> unit) -> err:(exn -> unit) -> unit
Takes the input and two continuations:
Raises ParseError in case of failure
val return : 'a -> 'a t
Always succeeds, without consuming its input
val pure : 'a -> 'a t
Synonym to CCParse.return
val (>|=) : 'a t -> ('a -> 'b) -> 'b t
Map
val map : ('a -> 'b) -> 'a t -> 'b t
val map2 : ('a -> 'b -> 'c) -> 'a t -> 'b t -> 'c t
val map3 : ('a -> 'b -> 'c -> 'd) ->
       'a t -> 'b t -> 'c t -> 'd t
val (>>=) : 'a t -> ('a -> 'b t) -> 'b t
Monadic bind
val (<*>) : ('a -> 'b) t -> 'a t -> 'b t
Applicative
val ( <* ) : 'a t -> 'b t -> 'a t
a <* b parses a into x, parses b and ignores its result, and returns x
val ( *> ) : 'b t -> 'a t -> 'a t
a *> b parses a, then parses b into x, and returns x. The results of a is ignored.
val fail : string -> 'a t
fail msg fails with the given message. It can trigger a backtrack
val failf : ('a, unit, string, 'b t) Pervasives.format4 -> 'a
Format.sprintf version of CCParse.fail
val parsing : string -> 'a t -> 'a t
parsing s p behaves the same as p, with the information that we are parsing s, if p fails
val eoi : unit t
Expect the end of input, fails otherwise
val nop : unit t
Succeed with ()
val char : char -> char t
char c parses the char c and nothing else
val char_if : (char -> bool) -> char t
char_if f parses a character c if f c = true
val chars_if : (char -> bool) -> string t
chars_if f parses a string of chars that satisfy f
val chars1_if : (char -> bool) -> string t
Same as CCParse.chars_if, but only non-empty strings
val endline : char t
Parses '\n'
val space : char t
Tab or space
val white : char t
Tab or space or newline
val skip_chars : (char -> bool) -> unit t
Skip 0 or more chars satisfying the predicate
val skip_space : unit t
Skip ' ' and '\t'
val skip_white : unit t
Skip ' ' and '\t' and '\n'
val is_alpha : char -> bool
Is the char a letter?
val is_num : char -> bool
Is the char a digit?
val is_alpha_num : char -> bool
val is_space : char -> bool
True on ' ' and '\t'
val is_white : char -> bool
True on ' ' and '\t' and '\n'
val (<|>) : 'a t -> 'a t -> 'a t
a <|> b tries to parse a, and if a fails without consuming any input, backtracks and tries to parse b, otherwise it fails as a. See CCParse.try_ to ensure a does not consume anything (but it is best to avoid wrapping large parsers with CCParse.try_)
val (<?>) : 'a t -> string -> 'a t
a <?> msg behaves like a, but if a fails without consuming any input, it fails with msg instead. Useful as the last choice in a series of <|>: a <|> b <|> c <?> "expected a|b|c"
val try_ : 'a t -> 'a t
try_ p tries to parse like p, but backtracks if p fails. Useful in combination with <|>
val suspend : (unit -> 'a t) -> 'a t
suspend f is the same as f (), but evaluates f () only when needed
val string : string -> string t
string s parses exactly the string s, and nothing else
val many : 'a t -> 'a list t
many p parses a list of p, eagerly (as long as possible)
val many1 : 'a t -> 'a list t
parses a non empty list
val skip : 'a t -> unit t
skip p parses zero or more times p and ignores its result
val sep : by:'b t -> 'a t -> 'a list t
sep ~by p parses a list of p separated by by
val sep1 : by:'b t -> 'a t -> 'a list t
sep1 ~by p parses a non empty list of p, separated by by
val fix : ('a t -> 'a t) -> 'a t
Fixpoint combinator
val memo : 'a t -> 'a t
Memoize the parser. memo p will behave like p, but when called in a state (read: position in input) it has already processed, memo p returns a result directly. The implementation uses an underlying hashtable. This can be costly in memory, but improve the run time a lot if there is a lot of backtracking involving p.

This function is not thread-safe.

val fix_memo : ('a t -> 'a t) -> 'a t
Same as CCParse.fix, but the fixpoint is memoized.
val get_lnum : int t
Reflects the current line number
val get_cnum : int t
Reflects the current column number
val get_pos : (int * int) t
Reflects the current (line, column) numbers

Parse

Those functions have a label ~p on the parser, since 0.14.

val parse : 'a t -> state -> 'a or_error
parse p st applies p on the input, and returns Ok x if p succeeds with x, or Error s otherwise
val parse_exn : 'a t -> state -> 'a
Unsafe version of CCParse.parse
Raises ParseError if it fails
val parse_string : 'a t -> string -> 'a or_error
Specialization of CCParse.parse for string inputs
val parse_string_exn : 'a t -> string -> 'a
Raises ParseError if it fails
val parse_file : 'a t -> string -> 'a or_error
parse_file p file parses file with p by opening the file and reading it whole.
val parse_file_exn : 'a t -> string -> 'a
Raises ParseError if it fails

Infix


module Infix: sig .. end

Utils

This is useful to parse OCaml-like values in a simple way.

module U: sig .. end