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| author | Matthew Pickering <matthewtpickering@gmail.com> | 2015-05-06 08:07:31 -0500 |
|---|---|---|
| committer | Austin Seipp <austin@well-typed.com> | 2015-05-06 08:09:43 -0500 |
| commit | caeae1a33e28745b51d952b034e253d3e51e0605 (patch) | |
| tree | e94c92ad944f9d2dac607f48abd9332a928311e3 /compiler/parser | |
| parent | fb54b2c11cc7f2cfbafa35b6a1819d7443aa5494 (diff) | |
| download | haskell-caeae1a33e28745b51d952b034e253d3e51e0605.tar.gz | |
Correct parsing of lifted empty list constructor
See #10299
Previously `'[]` was parsed to a `HsTyVar` rather than a
`HsExplicitListTy`. This patch fixes the
shift-reduce conflict which caused this problem.
Reviewed By: alanz, austin
Differential Revision: https://phabricator.haskell.org/D840
Diffstat (limited to 'compiler/parser')
| -rw-r--r-- | compiler/parser/Parser.y | 38 |
1 files changed, 21 insertions, 17 deletions
diff --git a/compiler/parser/Parser.y b/compiler/parser/Parser.y index aedfaf806d..3f2dc78e37 100644 --- a/compiler/parser/Parser.y +++ b/compiler/parser/Parser.y @@ -254,16 +254,6 @@ TODO: Why? ------------------------------------------------------------------------------- -state 432 contains 1 shift/reduce conflicts. - - atype -> SIMPLEQUOTE '[' . comma_types0 ']' (rule 318) - sysdcon -> '[' . ']' (rule 613) - - Conflict: ']' (empty comma_types0 reudes) - -TODO: Why? - -------------------------------------------------------------------------------- state 462 contains 1 shift/reduce conflicts. @@ -1692,7 +1682,7 @@ atype :: { LHsType RdrName } | TH_ID_SPLICE { sLL $1 $> $ mkHsSpliceTy $ sL1 $1 $ HsVar $ mkUnqual varName (getTH_ID_SPLICE $1) } -- see Note [Promotion] for the followings - | SIMPLEQUOTE qcon { sLL $1 $> $ HsTyVar $ unLoc $2 } + | SIMPLEQUOTE qcon_nowiredlist { sLL $1 $> $ HsTyVar $ unLoc $2 } | SIMPLEQUOTE '(' ctype ',' comma_types1 ')' {% addAnnotation (gl $3) AnnComma (gl $4) >> ams (sLL $1 $> $ HsExplicitTupleTy [] ($3 : $5)) @@ -2768,11 +2758,22 @@ name_var : var { $1 } ----------------------------------------- -- Data constructors -qcon :: { Located RdrName } - : qconid { $1 } - | '(' qconsym ')' {% ams (sLL $1 $> (unLoc $2)) - [mop $1,mj AnnVal $2,mcp $3] } - | sysdcon { sL1 $1 $ nameRdrName (dataConName (unLoc $1)) } +-- There are two different productions here as lifted list constructors +-- are parsed differently. + +qcon_nowiredlist :: { Located RdrName } + : gen_qcon { $1 } + | sysdcon_nolist { sL1 $1 $ nameRdrName (dataConName (unLoc $1)) } + +qcon :: { Located RdrName } + : gen_qcon { $1} + | sysdcon { sL1 $1 $ nameRdrName (dataConName (unLoc $1)) } + +gen_qcon :: { Located RdrName } + : qconid { $1 } + | '(' qconsym ')' {% ams (sLL $1 $> (unLoc $2)) + [mop $1,mj AnnVal $2,mcp $3] } + -- The case of '[:' ':]' is part of the production `parr' con :: { Located RdrName } @@ -2786,13 +2787,16 @@ con_list : con { sL1 $1 [$1] } | con ',' con_list {% addAnnotation (gl $1) AnnComma (gl $2) >> return (sLL $1 $> ($1 : unLoc $3)) } -sysdcon :: { Located DataCon } -- Wired in data constructors +sysdcon_nolist :: { Located DataCon } -- Wired in data constructors : '(' ')' {% ams (sLL $1 $> unitDataCon) [mop $1,mcp $2] } | '(' commas ')' {% ams (sLL $1 $> $ tupleCon BoxedTuple (snd $2 + 1)) (mop $1:mcp $3:(mcommas (fst $2))) } | '(#' '#)' {% ams (sLL $1 $> $ unboxedUnitDataCon) [mo $1,mc $2] } | '(#' commas '#)' {% ams (sLL $1 $> $ tupleCon UnboxedTuple (snd $2 + 1)) (mo $1:mc $3:(mcommas (fst $2))) } + +sysdcon :: { Located DataCon } + : sysdcon_nolist { $1 } | '[' ']' {% ams (sLL $1 $> nilDataCon) [mos $1,mcs $2] } conop :: { Located RdrName } |