Typecheck arrow notation
\begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
module TcArrows ( tcProc ) where
#include "HsVersions.h"
= addErrCtxt (cmdCtxt cmd) $
do { cmds_w_tys <- zipWithM new_cmd_ty cmd_args [1..]
; span <- getSrcSpanM
- ; [w_tv] <- tcInstSkolTyVars (ArrowSkol span) [alphaTyVar]
+ ; [w_tv] <- tcInstSkolTyVars ArrowSkol [alphaTyVar]
; let w_ty = mkTyVarTy w_tv -- Just a convenient starting point
-- a ((w,t1) .. tn) t
-- Check expr
; (expr', lie) <- escapeArrowScope (getLIE (tcMonoExpr expr e_ty))
- ; inst_binds <- tcSimplifyCheck sig_msg [w_tv] [] lie
+ ; loc <- getInstLoc (SigOrigin ArrowSkol)
+ ; inst_binds <- tcSimplifyCheck loc [w_tv] [] lie
-- Check that the polymorphic variable hasn't been unified with anything
-- and is not free in res_ty or the cmd_stk (i.e. t, t1..tn)
other -> (ty, [])
- sig_msg = ptext SLIT("expected type of a command form")
-
-----------------------------------------------------------------
-- Base case for illegal commands
-- This is where expressions that aren't commands get rejected