September 2017 Update

Task/SEDOLs/Jq/sedols.jq

@@ -0,0 +1,43 @@
+def ascii_upcase:
+  explode | map( if 97 <= . and . <= 122 then . - 32  else . end) | implode;
+
+def sedol_checksum:
+  def encode(a): 10 + (a|explode[0]) - ("A"|explode[0]);
+  . as $sed
+  | [1,3,1,7,3,9] as $sw
+  | reduce range(0;6) as $i
+      (0;
+       $sed[$i:$i+1] as $c
+       | if ( "0123456789" | index($c) )
+         then . + ($c|tonumber) * $sw[$i]
+         else . + encode($c) * $sw[$i]
+         end )
+  | (10 - (. % 10)) % 10 ;
+
+# error on error, else pass input to output
+def check_valid_sedol:
+  def has_vowel:
+    ("AEIOU"|explode) as $vowels
+    | reduce explode[] as $c
+        (false; if . then . else $vowels|index($c) end);
+
+  if has_vowel then error( "\(.) is not a valid SEDOL code" )
+  else .
+  end
+  | if length > 7 or length < 6 then
+      error( "\(.) is too long or too short to be valid SEDOL")
+    else .
+    end;
+
+def sedolize:
+  ascii_upcase as $in
+  | $in
+  | check_valid_sedol
+  | .[0:6] as $sedol
+  | ($sedol | sedol_checksum | tostring) as $sedolcheck
+  | ($sedol + $sedolcheck) as $ans
+  | if length == 7 and $ans != $in then
+         $ans + " (original \($in) has wrong checksum digit"
+    else $ans
+    end ;
+sedolize