strcspn and friends

4 files changed, 19 insertions, 0 deletions

diff --git a/lib/js/urweb.js b/lib/js/urweb.js
index be3d652a..0cc66bc7 100644
--- a/lib/js/urweb.js
+++ b/lib/js/urweb.js
@@ -360,6 +360,13 @@ function sidx(s, ch) {
   else
     return r;
 }
+function sspn(s, chs) {
+  for (var i = 0; i < s.length; ++i)
+    if (chs.indexOf(s[i]) != -1)
+      return i;
+
+  return null;
+}
 function schr(s, ch) {
   var r = s.indexOf(ch);
   if (r == -1)
diff --git a/lib/ur/basis.urs b/lib/ur/basis.urs
index d70ccc24..d3fbe037 100644
--- a/lib/ur/basis.urs
+++ b/lib/ur/basis.urs
@@ -59,6 +59,7 @@ val strsub : string -> int -> char
 val strsuffix : string -> int -> string
 val strchr : string -> char -> option string
 val strindex : string -> char -> option int
+val strcspn : string -> string -> option int
 val substring : string -> int -> int -> string
 
 class show
diff --git a/lib/ur/string.ur b/lib/ur/string.ur
index e6d5903e..e31bbc27 100644
--- a/lib/ur/string.ur
+++ b/lib/ur/string.ur
@@ -9,6 +9,8 @@ val suffix = Basis.strsuffix
 val index = Basis.strindex
 val atFirst = Basis.strchr
 
+fun mindex {Haystack = s, Needle = chs} = Basis.strcspn s chs
+
 fun substring s {Start = start, Len = len} = Basis.substring s start len
 
 fun split s ch =
@@ -16,3 +18,9 @@ fun split s ch =
         None => None
       | Some i => Some (substring s {Start = 0, Len = i},
                         substring s {Start = i + 1, Len = length s - i - 1})
+fun msplit {Haystack = s, Needle = chs} =
+    case mindex {Haystack = s, Needle = chs} of
+        None => None
+      | Some i => Some (substring s {Start = 0, Len = i},
+                        sub s i,
+                        substring s {Start = i + 1, Len = length s - i - 1})
diff --git a/lib/ur/string.urs b/lib/ur/string.urs
index 097a423f..8fd434b4 100644
--- a/lib/ur/string.urs
+++ b/lib/ur/string.urs
@@ -10,6 +10,9 @@ val suffix : t -> int -> string
 val index : t -> char -> option int
 val atFirst : t -> char -> option string
 
+val mindex : {Haystack : t, Needle : t} -> option int
+
 val substring : t -> {Start : int, Len : int} -> string
 
 val split : t -> char -> option (string * string)
+val msplit : {Haystack : t, Needle : t} -> option (string * char * string)