Bool -- True <=> this was a 'with' binding
-- (tmp, until 'with' is removed)
- | HsDo HsStmtContext
+ | HsDo (HsStmtContext Name) -- The parameterisation is unimportant
+ -- because in this context we never use
+ -- the FunRhs variant
[Stmt id] -- "do":one or more stmts
[id] -- Ids for [return,fail,>>=,>>]
-- Brutal but simple
ppr_expr (HsLit lit) = ppr lit
ppr_expr (HsOverLit lit) = ppr lit
-ppr_expr (HsLam match)
- = hsep [char '\\', nest 2 (pprMatch LambdaExpr match)]
+ppr_expr (HsLam match) = pprMatch LambdaExpr match
ppr_expr expr@(HsApp e1 e2)
= let (fun, args) = collect_args expr [] in
where
pp_name (FunRhs fun) = ppr fun -- Not pprBndr; the AbsBinds will
-- have printed the signature
+ pp_name LambdaExpr = char '\\'
pp_name other = empty
+
ppr_maybe_ty = case maybe_ty of
Just ty -> dcolon <+> ppr ty
Nothing -> empty
= hsep (map (\stmts -> ptext SLIT("| ") <> ppr stmts) stmtss)
pprStmt (RecStmt _ segment) = vcat (map ppr segment)
-pprDo :: OutputableBndr id => HsStmtContext -> [Stmt id] -> SDoc
+pprDo :: OutputableBndr id => HsStmtContext any -> [Stmt id] -> SDoc
pprDo DoExpr stmts = hang (ptext SLIT("do")) 2 (vcat (map ppr stmts))
pprDo MDoExpr stmts = hang (ptext SLIT("mdo")) 3 (vcat (map ppr stmts))
pprDo ListComp stmts = pprComp brackets stmts
%************************************************************************
\begin{code}
-data HsMatchContext id -- Context of a Match or Stmt
- = StmtCtxt HsStmtContext -- Do-stmt or list comprehension
- | FunRhs id -- Function binding for f
- | CaseAlt -- Guard on a case alternative
- | LambdaExpr -- Lambda
- | PatBindRhs -- Pattern binding
- | RecUpd -- Record update
+data HsMatchContext id -- Context of a Match
+ = FunRhs id -- Function binding for f
+ | CaseAlt -- Guard on a case alternative
+ | LambdaExpr -- Pattern of a lambda
+ | PatBindRhs -- Pattern binding
+ | RecUpd -- Record update [used only in DsExpr to tell matchWrapper
+ -- what sort of runtime error message to generate]
+ | StmtCtxt (HsStmtContext id) -- Pattern of a do-stmt or list comprehension
deriving ()
-data HsStmtContext
- = ListComp
- | DoExpr
- | MDoExpr -- recursive do-expression
- | PArrComp -- parallel array comprehension
- | PatGuard -- Never occurs in an HsDo expression, of course
+data HsStmtContext id
+ = ListComp
+ | DoExpr
+ | MDoExpr -- Recursive do-expression
+ | PArrComp -- Parallel array comprehension
+ | PatGuard (HsMatchContext id) -- Pattern guard for specified thing
\end{code}
\begin{code}
+isDoExpr :: HsStmtContext id -> Bool
isDoExpr DoExpr = True
isDoExpr MDoExpr = True
isDoExpr other = False
matchSeparator CaseAlt = ptext SLIT("->")
matchSeparator LambdaExpr = ptext SLIT("->")
matchSeparator PatBindRhs = ptext SLIT("=")
-matchSeparator (StmtCtxt _) = ptext SLIT("<-")
-matchSeparator RecUpd = panic "When is this used?"
+matchSeparator (StmtCtxt _) = ptext SLIT("<-")
+matchSeparator RecUpd = panic "unused"
\end{code}
\begin{code}
-pprMatchContext (FunRhs fun) = ptext SLIT("In the definition of") <+> quotes (ppr fun)
-pprMatchContext CaseAlt = ptext SLIT("In a case alternative")
-pprMatchContext RecUpd = ptext SLIT("In a record-update construct")
-pprMatchContext PatBindRhs = ptext SLIT("In a pattern binding")
-pprMatchContext LambdaExpr = ptext SLIT("In a lambda abstraction")
-pprMatchContext (StmtCtxt ctxt) = pprStmtCtxt ctxt
-
-pprStmtCtxt PatGuard = ptext SLIT("In a pattern guard")
-pprStmtCtxt DoExpr = ptext SLIT("In a 'do' expression pattern binding")
-pprStmtCtxt MDoExpr = ptext SLIT("In an 'mdo' expression pattern binding")
-pprStmtCtxt ListComp = ptext SLIT("In a 'list comprehension' pattern binding")
-pprStmtCtxt PArrComp = ptext SLIT("In an 'array comprehension' pattern binding")
+pprMatchContext (FunRhs fun) = ptext SLIT("the definition of") <+> quotes (ppr fun)
+pprMatchContext CaseAlt = ptext SLIT("a case alternative")
+pprMatchContext RecUpd = ptext SLIT("a record-update construct")
+pprMatchContext PatBindRhs = ptext SLIT("a pattern binding")
+pprMatchContext LambdaExpr = ptext SLIT("a lambda abstraction")
+pprMatchContext (StmtCtxt ctxt) = ptext SLIT("a pattern binding in") $$ pprStmtContext ctxt
+
+pprMatchRhsContext (FunRhs fun) = ptext SLIT("a right-hand side of function") <+> quotes (ppr fun)
+pprMatchRhsContext CaseAlt = ptext SLIT("the body of a case alternative")
+pprMatchRhsContext PatBindRhs = ptext SLIT("the right-hand side of a pattern binding")
+pprMatchRhsContext LambdaExpr = ptext SLIT("the body of a lambda")
+pprMatchRhsContext RecUpd = panic "pprMatchRhsContext"
+
+pprStmtContext (PatGuard ctxt) = ptext SLIT("a pattern guard for") $$ pprMatchContext ctxt
+pprStmtContext DoExpr = ptext SLIT("a 'do' expression")
+pprStmtContext MDoExpr = ptext SLIT("an 'mdo' expression")
+pprStmtContext ListComp = ptext SLIT("a list comprehension")
+pprStmtContext PArrComp = ptext SLIT("an array comprehension")
+
+-- Used for the result statement of comprehension
+-- e.g. the 'e' in [ e | ... ]
+-- or the 'r' in f x = r
+pprStmtResultContext (PatGuard ctxt) = pprMatchRhsContext ctxt
+pprStmtResultContext other = ptext SLIT("the result of") <+> pprStmtContext other
+
-- Used to generate the string for a *runtime* error message
-matchContextErrString (FunRhs fun) = "function " ++ showSDoc (ppr fun)
-matchContextErrString CaseAlt = "case"
-matchContextErrString PatBindRhs = "pattern binding"
-matchContextErrString RecUpd = "record update"
-matchContextErrString LambdaExpr = "lambda"
-matchContextErrString (StmtCtxt PatGuard) = "pattern gaurd"
-matchContextErrString (StmtCtxt DoExpr) = "'do' expression"
-matchContextErrString (StmtCtxt MDoExpr) = "'mdo' expression"
-matchContextErrString (StmtCtxt ListComp) = "list comprehension"
-matchContextErrString (StmtCtxt PArrComp) = "array comprehension"
+matchContextErrString (FunRhs fun) = "function " ++ showSDoc (ppr fun)
+matchContextErrString CaseAlt = "case"
+matchContextErrString PatBindRhs = "pattern binding"
+matchContextErrString RecUpd = "record update"
+matchContextErrString LambdaExpr = "lambda"
+matchContextErrString (StmtCtxt (PatGuard _)) = "pattern gaurd"
+matchContextErrString (StmtCtxt DoExpr) = "'do' expression"
+matchContextErrString (StmtCtxt MDoExpr) = "'mdo' expression"
+matchContextErrString (StmtCtxt ListComp) = "list comprehension"
+matchContextErrString (StmtCtxt PArrComp) = "array comprehension"
\end{code}
projects / ghc-hetmet.git / blobdiff