Commit da5cbb63 authored by simonpj's avatar simonpj
Browse files

[project @ 2005-04-04 15:22:25 by simonpj]

Further HsSyn wibbles
parent b5e9d715
......@@ -55,8 +55,8 @@ dsGRHSs :: HsMatchContext Name -> [Pat Id] -- These are to build a MatchContext
-> Type -- Type of RHS
-> DsM MatchResult
dsGRHSs kind pats (GRHSs grhss binds) rhs_ty
= mappM (dsGRHS kind pats rhs_ty) grhss `thenDs` \ match_results ->
dsGRHSs hs_ctx pats (GRHSs grhss binds) rhs_ty
= mappM (dsGRHS hs_ctx pats rhs_ty) grhss `thenDs` \ match_results ->
let
match_result1 = foldr1 combineMatchResults match_results
match_result2 = adjustMatchResultDs (dsLet binds) match_result1
......@@ -64,9 +64,8 @@ dsGRHSs kind pats (GRHSs grhss binds) rhs_ty
in
returnDs match_result2
dsGRHS kind pats rhs_ty (L loc (GRHS guards rhs))
= matchGuard (map unLoc guards) (DsMatchContext kind pats loc)
rhs rhs_ty
dsGRHS hs_ctx pats rhs_ty (L loc (GRHS guards rhs))
= matchGuards (map unLoc guards) hs_ctx rhs rhs_ty
\end{code}
......@@ -77,43 +76,43 @@ dsGRHS kind pats rhs_ty (L loc (GRHS guards rhs))
%************************************************************************
\begin{code}
matchGuard :: [Stmt Id] -- Guard
-> DsMatchContext -- Context
-> LHsExpr Id -- RHS
-> Type -- Type of RHS of guard
-> DsM MatchResult
matchGuards :: [Stmt Id] -- Guard
-> HsMatchContext Name -- Context
-> LHsExpr Id -- RHS
-> Type -- Type of RHS of guard
-> DsM MatchResult
-- See comments with HsExpr.Stmt re what an ExprStmt means
-- Here we must be in a guard context (not do-expression, nor list-comp)
matchGuard [] ctx rhs rhs_ty
matchGuards [] ctx rhs rhs_ty
= do { core_rhs <- dsLExpr rhs
; return (cantFailMatchResult core_rhs) }
-- ExprStmts must be guards
-- Turn an "otherwise" guard is a no-op
matchGuard (ExprStmt (L _ (HsVar v)) _ _ : stmts) ctx rhs rhs_ty
matchGuards (ExprStmt (L _ (HsVar v)) _ _ : stmts) ctx rhs rhs_ty
| v `hasKey` otherwiseIdKey
|| v `hasKey` getUnique trueDataConId
-- trueDataConId doesn't have the same
-- unique as trueDataCon
= matchGuard stmts ctx rhs rhs_ty
= matchGuards stmts ctx rhs rhs_ty
matchGuard (ExprStmt expr _ _ : stmts) ctx rhs rhs_ty
= matchGuard stmts ctx rhs rhs_ty `thenDs` \ match_result ->
matchGuards (ExprStmt expr _ _ : stmts) ctx rhs rhs_ty
= matchGuards stmts ctx rhs rhs_ty `thenDs` \ match_result ->
dsLExpr expr `thenDs` \ pred_expr ->
returnDs (mkGuardedMatchResult pred_expr match_result)
matchGuard (LetStmt binds : stmts) ctx rhs rhs_ty
= matchGuard stmts ctx rhs rhs_ty `thenDs` \ match_result ->
matchGuards (LetStmt binds : stmts) ctx rhs rhs_ty
= matchGuards stmts ctx rhs rhs_ty `thenDs` \ match_result ->
returnDs (adjustMatchResultDs (dsLet binds) match_result)
-- NB the dsLet occurs inside the match_result
-- Reason: dsLet takes the body expression as its argument
-- so we can't desugar the bindings without the
-- body expression in hand
matchGuard (BindStmt pat bind_rhs _ _ : stmts) ctx rhs rhs_ty
= matchGuard stmts ctx rhs rhs_ty `thenDs` \ match_result ->
matchGuards (BindStmt pat bind_rhs _ _ : stmts) ctx rhs rhs_ty
= matchGuards stmts ctx rhs rhs_ty `thenDs` \ match_result ->
dsLExpr bind_rhs `thenDs` \ core_rhs ->
matchSinglePat core_rhs ctx pat rhs_ty match_result
\end{code}
......
......@@ -113,9 +113,6 @@ dsIncompleteWarn ctx@(DsMatchContext kind _ _) pats = dsWarn warn
dots | pats `lengthExceeds` maximum_output = ptext SLIT("...")
| otherwise = empty
pp_context NoMatchContext msg rest_of_msg_fun
= (noSrcSpan, ptext SLIT("Some match(es)") <+> hang msg 8 (rest_of_msg_fun id))
pp_context (DsMatchContext kind pats loc) msg rest_of_msg_fun
= (loc, vcat [ptext SLIT("Pattern match(es)") <+> msg,
sep [ptext SLIT("In") <+> ppr_match <> char ':', nest 4 (rest_of_msg_fun pref)]])
......
\begin{code}
module TcExpr where
import HsSyn ( LHsExpr )
import HsSyn ( HsExpr, LHsExpr )
import Name ( Name )
import Var ( Id )
import TcType ( TcType, Expected )
......
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