From 0279339ee9a7b61ebcb3f64846d94f8171872737 Mon Sep 17 00:00:00 2001

From: "Richard W.M. Jones" <rjones@redhat.com>

Date: Tue, 11 Apr 2017 08:32:04 +0100

Subject: [PATCH] mllib: Add Char.hexdigit function.

Same as the function defined in fish/fish.c.

(cherry picked from commit ef261d69ed199cc07474a36c890f63df461b35a7)

---

 mllib/common_utils.ml  | 19 +++++++++++++++++++

 mllib/common_utils.mli |  4 ++++

 2 files changed, 23 insertions(+)

diff --git a/mllib/common_utils.ml b/mllib/common_utils.ml

index e1d6329..4593614 100644

--- a/mllib/common_utils.ml

+++ b/mllib/common_utils.ml

@@ -70,6 +70,25 @@ module Char = struct

       | 'a'..'z' -> true

       | 'A'..'Z' -> true

       | _ -> false

+

+    let hexdigit = function

+      | '0' -> 0

+      | '1' -> 1

+      | '2' -> 2

+      | '3' -> 3

+      | '4' -> 4

+      | '5' -> 5

+      | '6' -> 6

+      | '7' -> 7

+      | '8' -> 8

+      | '9' -> 9

+      | 'a' | 'A' -> 10

+      | 'b' | 'B' -> 11

+      | 'c' | 'C' -> 12

+      | 'd' | 'D' -> 13

+      | 'e' | 'E' -> 14

+      | 'f' | 'F' -> 15

+      | _ -> -1

 end

 module String = struct

diff --git a/mllib/common_utils.mli b/mllib/common_utils.mli

index 1cd38ba..ec41a8f 100644

--- a/mllib/common_utils.mli

+++ b/mllib/common_utils.mli

@@ -43,6 +43,10 @@ module Char : sig

     (** Return true if the character is a US ASCII 7 bit alphabetic. *)

     val isalnum : char -> bool

     (** Return true if the character is a US ASCII 7 bit alphanumeric. *)

+

+    val hexdigit : char -> int

+    (** Return the value of a hex digit.  If the char is not in

+        the set [[0-9a-fA-F]] then this returns [-1]. *)

 end

 (** Override the Char module from stdlib. *)

-- 

2.9.4