Add isatom()

1 files changed, 13 insertions, 0 deletions

@@ -172,5 +172,18 @@ function m.islist (x)
         end
 end
 
+function m.isatom (x)
+        if x == m.null then
+                return true -- '() is the only value that is both atom and list
+        elseif m.luatype(x) == "table" then
+                -- generally, anything that's implemented as a table is *not* an
+                -- atom, at least as I will define it.  (it's not an actual
+                -- scheme procedure)
+                return false
+        else
+                return true
+        end
+end
+
 --------
 return m