[Libguestfs] [PATCH v3 4/6] mllib: modify nsplit to take optional noempty and count arguments
Added two new optional arguments to nsplit:
* noempty: if set to false empty elements are not stored in the returned
list. The default is to keep the empty elements
* count: specifies how many splits to perform; negative count
(the default) means do as many splits as possible
Signed-off-by: Tomáš Golembiovský <tgolembi(a)redhat.com>
---
mllib/common_utils.ml | 12 +++++++++---
mllib/common_utils.mli | 12 ++++++++++--
2 files changed, 19 insertions(+), 5 deletions(-)
diff --git a/mllib/common_utils.ml b/mllib/common_utils.ml
index 78618f5..2d373f9 100644
--- a/mllib/common_utils.ml
+++ b/mllib/common_utils.ml
@@ -92,15 +92,21 @@ module String = struct
s' ^ s2 ^ replace s'' s1 s2
)
- let rec nsplit sep str =
+ let rec nsplit ?(noempty = true) ?(count = -1) sep str =
let len = length str in
let seplen = length sep in
let i = find str sep in
- if i = -1 then [str]
+ if i = -1 || count = 0 then [str]
else (
let s' = sub str 0 i in
let s'' = sub str (i+seplen) (len-i-seplen) in
- s' :: nsplit sep s''
+ let elem, count =
+ if s' = "" && noempty then
+ [], count
+ else
+ [s'], if count > 0 then count-1 else count
+ in
+ elem @ nsplit ~noempty:noempty ~count:count sep s''
)
let split sep str =
diff --git a/mllib/common_utils.mli b/mllib/common_utils.mli
index ad43345..bcd459d 100644
--- a/mllib/common_utils.mli
+++ b/mllib/common_utils.mli
@@ -64,9 +64,17 @@ module String : sig
val replace : string -> string -> string -> string
(** [replace str s1 s2] replaces all instances of [s1] appearing in
[str] with [s2]. *)
- val nsplit : string -> string -> string list
+ val nsplit : ?noempty:bool -> ?count:int -> string -> string -> string
list
(** [nsplit sep str] splits [str] into multiple strings at each
- separator [sep]. *)
+ separator [sep].
+
+ If [noempty] is set to true empty elements are not included in the
+ list. By default empty elements are kept.
+
+ If [count] is specified it says how many splits to perform. I.e. the
+ returned array will have at most [count]+1 elements. Negative [count]
+ (the default) means do as many splits as possible.
+ *)
val split : string -> string -> string * string
(** [split sep str] splits [str] at the first occurrence of the
separator [sep], returning the part before and the part after.
--
2.10.2