Substring search and replace functions. They use the Knuth-Morris-Pratt algorithm (KMP) under the hood.
The functions in the Search_pattern
module allow the program to preprocess the
searched pattern once and then use it many times without further allocations.
include sig ... end
val sexp_of_t : t ‑> Base.Sexp.t
val create : string ‑> t
create pattern
preprocesses pattern
as per KMP, building an int array
of
length length pattern
. All inputs are valid.
val index : ?pos:int ‑> t ‑> in_:string ‑> int option
pos < 0
or pos >= length string
result in no match (hence index
returns
None
and index_exn
raises).
val index_exn : ?pos:int ‑> t ‑> in_:string ‑> int
val index_all : t ‑> may_overlap:bool ‑> in_:string ‑> int list
may_overlap
determines whether after a successful match, index_all
should start
looking for another one at the very next position (~may_overlap:true
), or jump to
the end of that match and continue from there (~may_overlap:false
), e.g.:
index_all (create "aaa") ~may_overlap:false ~in_:"aaaaBaaaaaa" = [0; 5; 8]
index_all (create "aaa") ~may_overlap:true ~in_:"aaaaBaaaaaa" = [0; 1; 5; 6; 7;
8]
E.g., replace_all
internally calls index_all ~may_overlap:false
.
val replace_first : ?pos:int ‑> t ‑> in_:string ‑> with_:string ‑> string
Note that the result of replace_all pattern ~in_:text ~with_:r
may still
contain pattern
, e.g.,
replace_all (create "bc") ~in_:"aabbcc" ~with_:"cb" = "aabcbc"
val replace_all : t ‑> in_:string ‑> with_:string ‑> string