-followFs :: FieldSelector -> Gen()
-followFs FieldHd = tell [Instr "ldc" [Lit 1] "select hd"
- ,Instr "sub" [] "select hd"]
-followFs FieldTl = tell []
-followFs FieldFst = tell [Instr "ldc" [Lit 1] "select fst"
- ,Instr "sub" [] "select fst"]
-followFs FieldSnd = tell []
+followFs :: [FieldSelector] -> Gen()
+followFs [] = tell []
+followFs [FieldHd:fs] = tell [Instr "ldc" [Lit 1] "select hd"
+ ,Instr "sub" [] "select hd"]
+ >>| followFs fs
+followFs [FieldTl] = tell []
+followFs [FieldTl:fs] = tell [Instr "lda" [Lit 0] ""]
+ >>| followFs fs
+followFs [FieldFst:fs] = tell [Instr "ldc" [Lit 1] "select fst"
+ ,Instr "sub" [] "select fst"]
+ >>| followFs fs
+followFs [FieldSnd:fs] = tell [Instr "lda" [Lit 0] ""]
+ >>| followFs fs
+followFs [FieldSnd] = tell []