Reorganization

1 files changed, 24 insertions, 11 deletions

@@ -1,22 +1,35 @@
---- lam.util
+--- lam.util --- utility functions
 
 local m = {}
+local string = string
+local utf8 = require("utf8")
 
+m.luaerror = error
+
+-- signal an error
+-- WHERE is where in the process; DESC is a description of the error; the rest
+-- are "irritants"
+function m.error (desc, ...)
+        m.luaerror(string.format("%s: %s", desc, table.concat({...}, " ")
+        ))
+end
+
+-- remove an element from the front of TBL
 function m.pop (tbl)
-        --[[ Remove the first element from TBL. ]]
         return table.remove(tbl, 1)
 end
 
-function m.assert_arity (r, min, max)
-        local rmin = min or 0
-        local rmax = max or 1/0 -- infinity
-        local rlen = #r
-        if rlen < rmin or rlen > rmax then
-                error(string.format("Wrong arity: %s; expecting %s",
-                                rlen,
-                                rmin == rmax and rmin or (rmin..".."..rmax)))
+function m.tochars (str)
+        local cs = {}
+        for _, code in utf8.codes(str) do
+                table.insert(cs, code)
         end
+        return cs
+end
+
+function m.constantly (x)
+        return function () return x end
 end
 
----
+--------
 return m