package sexp

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package sexp
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This module contains the type for a regexp-like query which can be used to match sexps and extract subsexps.

A sexp sequence is a list of sexps. We use the term sequence to differentiate from a sexp which is a list of sexps. Typically a sexp sequence corresponds to a sublist of a sexp list.

A query is a object that when applied to a sexp sequence, may fail to match, or else may match by successfully consuming zero or more elements from the head of that sequence.

Queries may match with multiplicity greater than 1, each match independently consuming the same or different prefixes of the head of the list.

Each match may also capture various sequences (which must be a subsequence of the consumed sexp sequences) returning those captures to the user.

Captures do not need to be uniquely numbered or named within a given query, since with the Or_* variants, one can legitimately write branched queries where each branch might capture into the same label, but only one branch at a time is expected to actually match.

However, if a given single match of the pattern captures two different expressions into the same label simultaneously, it is unspecified which of the two expressions will actually be returned for that label.

module Set_kind : sig ... end
type t =
  1. | Capture_unlabeled of t
    (*

    Capture_unlabeled t is equivalent to Capture_to_number (i, t) where i starts at 0 and increments each time an unlabeled capture appears in the query. Syntax: %.

    *)
  2. | Capture_to_number of int * t
    (*

    Capture_to_number (i, t) applies the subquery t, associating each consumed sequence to the label Int.to_string i. Example syntax: %0

    *)
  3. | Capture_to_name of string * t
    (*

    Capture_to_name (n, t) applies the subquery t, associating each consumed sequence to the label n. Example syntax: %foo

    *)
  4. | Any
    (*

    Consume a single sexp or fail to match. Syntax: .

    *)
  5. | Atom of string
    (*

    Consumes an atom if it matches this exact string. Example syntax: foo

    *)
  6. | Atom_regex of string
    (*

    Consumes an atom if it matches this regex. Example syntax: /foo/

    *)
  7. | Sequence of t list
    (*

    Recursively applies each t against the remaining tail unconsumed by previous ts in the sequence. Example syntax: [t1 t2 t3]

    *)
  8. | Star of t
    (*

    Iteratively applies all of [ Sequence []; Sequence [t]; Sequence [t; t]; ... ], with a special-case guard against an infinite loop if t itself can consume zero elements. Example syntax: t*

    *)
  9. | Star_greedy of t
    (*

    Same as Star, but tries possiblities in reverse order. Example syntax: t*+

    *)
  10. | Plus of t
    (*

    Iteratively applies all of [ Sequence [t]; Sequence [t; t]; ... ], with a special-case guard against an infinite loop if t itself can consume zero elements. Example syntax: t+

    *)
  11. | Plus_greedy of t
    (*

    Same as Plus, but tries possiblities in reverse order. Example syntax: t++

    *)
  12. | Maybe of t
    (*

    Iteratively applies both of [ Sequence []; Sequence [t] ], with a special-case guard to match with multiplicity only 1 if t itself can consume zero elements. Example syntax: t?

    *)
  13. | Maybe_greedy of t
    (*

    Same as Maybe, but tries possiblities in reverse order. Example syntax: t?+

    *)
  14. | List of t
    (*

    Consumes a sexp if it is a list, applying t to the sequence of the list's elements and requiring any successful matches by t to consume the entire sequence. Example syntax: (t1 t2 t3)

    *)
  15. | Set of (t * Set_kind.t) list
    (*

    Consumes a sexp if it is a list, recursively applying each subquery t iteratively one by one to each element of the sublist where that element is given as a singleton sequence, requiring that subquery to match that element. Multiple terms of the query may match the same list element. The cartesian product of all possible matches over the subqueries will be the result. See also the documentation above for Set_kind for how it may modify this behavior. Example syntax: {t1 t2??}

    *)
  16. | Subsearch of t
    (*

    Subsearch t matches some sequence S of sexps if S contains a subsequence which t matches, or if List (Subsearch t) matches one of the sexps in S. Example syntax: .. t

    *)
  17. | And of t list
    (*

    Consumes a sequence of sexps only if every t provided has a successful match consuming exactly that sequence of sexps. Example syntax: t1 & t2

    *)
  18. | Or_shortcircuiting of t list
    (*

    Applies each t iteratively, stopping after iterating through all matches of the first t that has any matches. In other words, Or_shortcircuiting [t1; t2; ...; ti; ...] matches if and only if ti matches and none of queries before ti match. Example syntax: none

    *)
  19. | Or_all of t list
    (*

    Applies each t iteratively, matching according to the union of their matches. In other words, Or_all [t1; ...; tn] matches if and only if at least one of the ti matches. If more than one of the ti matches, it is undefined which of the matching terms will give the captures. Example syntax: t1 | t2

    *)
  20. | First_match_only of t
    (*

    Applies t and stops after the first time it matches. Example syntax: !t

    *)
include Sexplib0.Sexpable.S with type t := t
val t_of_sexp : Sexplib0.Sexp.t -> t
val sexp_of_t : t -> Sexplib0.Sexp.t
val iter : t -> f:(t -> unit) -> unit
module Capture_count : sig ... end
val count_captures : t -> Capture_count.t
val validate_all_captures_labeled_or_all_unlabeled_exn : t -> unit