Added some training wheels for functions.

lib/training_wheels.nom

@@ -26,3 +26,19 @@ parse [error!, panic!, fail!, abort!] as: barf!
 parse [error %, panic %, fail %, abort %] as: barf %
 parse [assert %condition %message] as: assume %condition or barf %message
 parse [%cond ? %if_true %if_false] as: %if_true if %cond else %if_false
+compile [function %args %body, lambda %args %body] to
+    %body_lua <- (%body as lua)
+    %statements <- ((%body_lua's "statements") or "return \(%body_lua's "expr");")
+    %locals <- (% for all ((%body_lua's "locals") or []))
+    for all (%args's "value")
+        lua> "utils.remove_from_list(\%locals, \(% as lua expr));"
+    if: (size of %locals) > 0
+        %statements <- "local \(%locals joined with ", ");\n\%statements"
+
+    return {..}
+        expr: ".."
+            (function(\(((% as lua expr) for all (%args's "value")) joined with ", "))
+                \%statements
+            end)
+parse [function %name %args %body] as: %name <- (function %args %body)
+compile [call %fn %args] to {expr:"\(%fn as lua expr)(unpack(\(%args as lua expr)))"}