[Xen-API] [PATCH] CP-1622: Listext function to replace the value for a key in an assoc list

[Rob Hoes <rob.hoes@xxxxxxxxxx>]

# HG changeset patch
# User Rob Hoes <rob.hoes@xxxxxxxxxx>
CP-1622: Listext function to replace the value for a key in an assoc list

Signed-off-by: Rob Hoes <rob.hoes@xxxxxxxxxx>

diff -r 3e1beafe76b5 stdext/listext.ml
--- a/stdext/listext.ml Tue Feb 16 22:40:11 2010 +0000
+++ b/stdext/listext.ml Tue Feb 16 22:47:58 2010 +0000
@@ -192,4 +192,13 @@
 let rec tails = function
     | [] -> [[]]
     | (_::xs) as l -> l :: tails xs
+
+let rec replace_assoc key new_value = function
+       | [] -> []
+       | (k, _) as p :: tl ->
+               if k = key then
+                       (key, new_value) :: tl
+               else
+                       p :: replace_assoc key new_value tl
+
 end
diff -r 3e1beafe76b5 stdext/listext.mli
--- a/stdext/listext.mli        Tue Feb 16 22:40:11 2010 +0000
+++ b/stdext/listext.mli        Tue Feb 16 22:47:58 2010 +0000
@@ -177,4 +177,6 @@
        
     val tails : 'a list -> ('a list) list
 
+       (** Replace the value belonging to a key in an association list. *)
+       val replace_assoc : 'a -> 'b -> ('a * 'b) list -> ('a * 'b) list
   end

Attachment: list-replace-assoc
Description: Text document

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