msyds/gf-core
1
0
Fork 0
forked from GitHub/gf-core
Code Pull Requests Activity

use of 'head' in TypeCheck/RConcrete created an uncomprehensible error message. Now checking for the emptiness of the list concerned, so that the error can be found.

Browse Source
This commit is contained in:
aarne
2014-10-20 20:06:46 +00:00
parent 1e0d078ae2
commit fe6d2738a0
1 changed files with 3 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
src/compiler/GF/Compile/TypeCheck/RConcrete.hs
View File

@@ -386,7 +386,9 @@ getOverload gr g mt ot = case appForm ot of
---- "with argument types" <+> hsep (map (ppTerm Qualified 0) tys) $$
"resolved by selecting the first of the alternatives" $$
nest 2 (vcat [ppTerm Qualified 0 fun | (_,ty,fun) <- vfs1 ++ if null vfs1 then vfs2 else []])
return $ head [(mkApp fun tts,val) | (val,fun) <- nps1 ++ nps2]
case [(mkApp fun tts,val) | (val,fun) <- nps1 ++ nps2] of
[] -> checkError $ "no alternatives left when resolving" <+> ppTerm Unqualified 0 f
h:_ -> return h
matchVal mt v = elem mt [Nothing,Just v,Just (unlocked v)]