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* Modules (#13009)Sylvain Henry2020-04-181-3294/+0
| | | | | | | | | | | | | | * SysTools * Parser * GHC.Builtin * GHC.Iface.Recomp * Settings Update Haddock submodule Metric Decrease: Naperian parsing001
* Modules: type-checker (#13009)Sylvain Henry2020-04-071-1/+1
| | | | Update Haddock submodule
* Modules: Types (#13009)Sylvain Henry2020-03-291-6/+6
| | | | | | | Update Haddock submodule Metric Increase: haddock.compiler
* Monotonic locations (#17632)Vladislav Zavialov2020-02-291-106/+117
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When GHC is parsing a file generated by a tool, e.g. by the C preprocessor, the tool may insert #line pragmas to adjust the locations reported to the user. As the result, the locations recorded in RealSrcLoc are not monotonic. Elements that appear later in the StringBuffer are not guaranteed to have a higher line/column number. In fact, there are no guarantees whatsoever, as #line pragmas can arbitrarily modify locations. This lack of guarantees makes ideas such as #17544 infeasible. This patch adds an additional bit of information to every SrcLoc: newtype BufPos = BufPos { bufPos :: Int } A BufPos represents the location in the StringBuffer, unaffected by any pragmas. Updates haddock submodule. Metric Increase: haddock.Cabal haddock.base haddock.compiler MultiLayerModules Naperian parsing001 T12150
* Modules: Driver (#13009)Sylvain Henry2020-02-211-1/+1
| | | | submodule updates: nofib, haddock
* Parser API annotations: RealSrcLocVladislav Zavialov2020-02-211-22/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During parsing, GHC collects lexical information about AST nodes and stores it in a map. It is needed to faithfully restore original source code, e.g. compare these expressions: a = b a = b The position of the equality sign is not recorded in the AST, so it must be stored elsewhere. This system is described in Note [Api annotations]. Before this patch, the mapping was represented by: Map (SrcSpan, AnnKeywordId) SrcSpan After this patch, the mapping is represented by: Map (RealSrcSpan, AnnKeywordId) RealSrcSpan The motivation behind this change is to avoid using the Ord SrcSpan instance (required by Map here), as it interferes with #17632 (see the discussion there). SrcSpan is isomorphic to Either String RealSrcSpan, but we shouldn't use those strings as Map keys. Those strings are intended as hints to the user, e.g. "<interactive>" or "<compiler-generated code>", so they are not a valid way to identify nodes in the source code.
* Remove the MonadFail P instanceVladislav Zavialov2020-02-181-9/+1
| | | | | | | | | | | | | There were two issues with this instance: * its existence meant that a pattern match failure in the P monad would produce a user-visible parse error, but the error message would not be helpful to the user * due to the MFP migration strategy, we had to use CPP in Lexer.x, and that created issues for #17750 Updates haddock submodule.
* TemplateHaskellQuotes: Allow nested splicesMatthew Pickering2020-02-111-3/+3
| | | | | | There is no issue with nested splices as they do not require any compile time code execution. All execution is delayed until the top-level splice.
* Disable two warnings for files that trigger themTom Ellis2020-01-271-0/+1
| | | | | | incomplete-uni-patterns and incomplete-record-updates will be in -Wall at a future date, so prepare for that by disabling those warnings on files that trigger them.
* Add lexerDbg to dump the tokens fed to the parserVladislav Zavialov2020-01-041-2/+8
| | | | | This a small utility function that comes in handy when debugging the lexer and the parser.
* Fix more typosBrian Wignall2019-12-021-1/+1
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* Whitespace-sensitive bang patterns (#1087, #17162)wip/whitespace-and-lookaheadVladislav Zavialov2019-11-271-66/+187
| | | | | | | | | | | | | | | | | | This patch implements a part of GHC Proposal #229 that covers five operators: * the bang operator (!) * the tilde operator (~) * the at operator (@) * the dollar operator ($) * the double dollar operator ($$) Based on surrounding whitespace, these operators are disambiguated into bang patterns, lazy patterns, strictness annotations, type applications, splices, and typed splices. This patch doesn't cover the (-) operator or the -Woperator-whitespace warning, which are left as future work.
* PV is not P (#16611)Vladislav Zavialov2019-07-151-24/+51
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* Decouple AddAnn from PVladislav Zavialov2019-07-151-6/+7
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* Implement ImportQualifiedPostShayne Fletcher2019-05-081-0/+2
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* Pattern/expression ambiguity resolutionVladislav Zavialov2019-05-031-15/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes 'EWildPat', 'EAsPat', 'EViewPat', and 'ELazyPat' from 'HsExpr' by using the ambiguity resolution system introduced earlier for the command/expression ambiguity. Problem: there are places in the grammar where we do not know whether we are parsing an expression or a pattern, for example: do { Con a b <- x } -- 'Con a b' is a pattern do { Con a b } -- 'Con a b' is an expression Until we encounter binding syntax (<-) we don't know whether to parse 'Con a b' as an expression or a pattern. The old solution was to parse as HsExpr always, and rejig later: checkPattern :: LHsExpr GhcPs -> P (LPat GhcPs) This meant polluting 'HsExpr' with pattern-related constructors. In other words, limitations of the parser were affecting the AST, and all other code (the renamer, the typechecker) had to deal with these extra constructors. We fix this abstraction leak by parsing into an overloaded representation: class DisambECP b where ... newtype ECP = ECP { runECP_PV :: forall b. DisambECP b => PV (Located b) } See Note [Ambiguous syntactic categories] for details. Now the intricacies of parsing have no effect on the hsSyn AST when it comes to the expression/pattern ambiguity.
* checkPattern error hint is PV contextVladislav Zavialov2019-04-251-9/+8
| | | | | There is a hint added to error messages reported in checkPattern. Instead of passing it manually, we put it in a ReaderT environment inside PV.
* Introduce MonadP, make PV a newtypeVladislav Zavialov2019-04-251-38/+48
| | | | | | | | | | | Previously we defined type PV = P, this had the downside that if we wanted to change PV, we would have to modify P as well. Now PV is free to evolve independently from P. The common operations addError, addFatalError, getBit, addAnnsAt, were abstracted into a class called MonadP.
* Update Wiki URLs to point to GitLabTakenobu Tani2019-03-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | This moves all URL references to Trac Wiki to their corresponding GitLab counterparts. This substitution is classified as follows: 1. Automated substitution using sed with Ben's mapping rule [1] Old: ghc.haskell.org/trac/ghc/wiki/XxxYyy... New: gitlab.haskell.org/ghc/ghc/wikis/xxx-yyy... 2. Manual substitution for URLs containing `#` index Old: ghc.haskell.org/trac/ghc/wiki/XxxYyy...#Zzz New: gitlab.haskell.org/ghc/ghc/wikis/xxx-yyy...#zzz 3. Manual substitution for strings starting with `Commentary` Old: Commentary/XxxYyy... New: commentary/xxx-yyy... See also !539 [1]: https://gitlab.haskell.org/bgamari/gitlab-migration/blob/master/wiki-mapping.json
* Update Trac ticket URLs to point to GitLabRyan Scott2019-03-151-1/+1
| | | | | This moves all URL references to Trac tickets to their corresponding GitLab counterparts.
* Lexer: turn some fatal errors into non-fatal onesAlec Theriault2019-03-011-18/+24
| | | | | | | | | | The following previously fatal lexer errors are now non-fatal: * errors about enabling `LambdaCase` * errors about enabling `NumericUnderscores` * errors about having valid characters in primitive strings See #16270
* Fix warnings and fatal parsing errorsVladislav Zavialov2019-02-171-33/+52
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* 'forall' always a keyword, plus the dot type operatorVladislav Zavialov2019-02-151-4/+2
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* Fix #15849 by checking whether there's a do blocknineonine2019-02-121-1/+2
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* Fix inverted position pragma flag in parser APIAlec Theriault2019-02-101-1/+1
| | | | | | | | The behviour of `lexTokenStream` around position pragma was accidentally inverted in 469fe6133646df5568c9486de2202124cb734242. This fixes that bug. This also unbreaks #16239.
* Lexer: Alternate Layout Rule injects actual not virtual bracesAlan Zimmerman2019-02-081-15/+17
| | | | | | | | | | | | | | | | | | | | | | | | | When the alternate layout rule is activated via a pragma, it injects tokens for { and } to make sure that the source is parsed properly. But it injects ITocurly and ITccurly, rather than their virtual counterparts ITvocurly and ITvccurly. This causes problems for ghc-exactprint, which tries to print these. Likewise, any injected ITsemi should have a zero-width SrcSpan. Test case (the existing T13087.hs) {-# LANGUAGE AlternativeLayoutRule #-} {-# LANGUAGE LambdaCase #-} isOne :: Int -> Bool isOne = \case 1 -> True _ -> False main = return () Closes #16279
* Report multiple errorsVladislav Zavialov2019-02-031-1/+12
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* Prepare source-tree for base-4.13 MFP bumpHerbert Valerio Riedel2019-01-181-1/+4
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* 'DynFlag'-free version of 'mkParserFlags'Alec Theriault2019-01-171-298/+268
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This is a fixed version of the reverted d2fbc33c4ff3074126ab71654af8bbf8a46e4e11 and 5aa29231ab7603537284eff5e4caff3a73dba6d2. Obtaining a `DynFlags` is difficult, making using the lexer/parser for pure parsing/lexing unreasonably difficult, even with `mkPStatePure`. This is despite the fact that we only really need * language extension flags * warning flags * a handful of boolean options The new `mkParserFlags'` function makes is easier to directly construct a `ParserFlags`. Furthermore, since `pExtsBitmap` is just a footgun, I've gone ahead and made `ParserFlags` an abstract type. Also, we now export `ExtBits` and `getBit` instead of defining/exporting a bunch of boilerplate functions that test for a particular 'ExtBits'. In the process, I also * cleaned up an unneeded special case for `ITstatic` * made `UsePosPrags` another variant of `ExtBits` * made the logic in `reservedSymsFM` match that of `reservedWordsFM` Test Plan: make test Reviewers: bgamari, alanz, tdammers Subscribers: sjakobi, tdammers, rwbarton, mpickering, carter GHC Trac Issues: #11301 Differential Revision: https://phabricator.haskell.org/D5405
* [TTG: Handling Source Locations] Foundation and PatShayan-Najd2018-11-241-16/+16
| | | | | | | | | | | | | | | | | | This patch removes the ping-pong style from HsPat (only, for now), using the plan laid out at https://ghc.haskell.org/trac/ghc/wiki/ImplementingTreesThatGrow/HandlingSourceLocations (solution A). - the class `HasSrcSpan`, and its functions (e.g., `cL` and `dL`), are introduced - some instances of `HasSrcSpan` are introduced - some constructors `L` are replaced with `cL` - some patterns `L` are replaced with `dL->L` view pattern - some type annotation are necessarily updated (e.g., `Pat p` --> `Pat (GhcPass p)`) Phab diff: D5036 Trac Issues #15495 Updates haddock submodule
* Revert "'DynFlag'-free version of 'mkParserFlags'"Ben Gamari2018-11-231-69/+37
| | | | This reverts commit 5aa29231ab7603537284eff5e4caff3a73dba6d2.
* Revert "Simplify 'ExtBits' in the lexer"Ben Gamari2018-11-231-215/+283
| | | | This reverts commit d2fbc33c4ff3074126ab71654af8bbf8a46e4e11.
* Simplify 'ExtBits' in the lexerAlec Theriault2018-11-221-283/+215
| | | | | | | | | | | | | | | | | | The main change is to export 'ExtBits' instead of defining/exporting a bunch of boilerplate functions that test for a particular 'ExtBits'. In the process, I also * cleaned up an unneeded special case for 'ITstatic' * made 'UsePosPrags' another variant of 'ExtBits' * made the logic in 'reservedSymsFM' match that of 'reservedWordsFM' Test Plan: make test Reviewers: bgamari, alanz Subscribers: sjakobi, rwbarton, mpickering, carter Differential Revision: https://phabricator.haskell.org/D5332
* 'DynFlag'-free version of 'mkParserFlags'Alec Theriault2018-11-221-37/+69
| | | | | | | | | | | | | | | | | | | | | | | | | Obtaining a `DynFlags` is difficult, making using the lexer/parser for pure parsing/lexing unreasonably difficult, even with `mkPStatePure`. This is despite the fact that we only really need * language extension flags * warning flags * a handful of boolean options The new `mkParserFlags'` function makes is easier to directly construct a `ParserFlags`. Furthermore, since `pExtsBitmap` is just a footgun, I've gone ahead and made `ParserFlags` an abstract type. Reviewers: bgamari, alanz, sjakobi Reviewed By: bgamari, sjakobi Subscribers: mpickering, sjakobi, rwbarton, carter GHC Trac Issues: #11301 Differential Revision: https://phabricator.haskell.org/D5269
* Remove warnings-silencing flags for code generated by AlexSimon Jakobi2018-11-221-45/+9
| | | | | | | | | | | | | | | | | | Current versions of Alex don't seem to produce as many warnings any more. In order to silence a warning and to avoid overlong lines, I've taken the liberty of refactoring 'tok_num'. Test Plan: ./validate Reviewers: bgamari, simonmar Reviewed By: simonmar Subscribers: erikd, rwbarton, carter Differential Revision: https://phabricator.haskell.org/D5319
* Trigger multiline mode in GHCi on '\case' (#13087)Alec Theriault2018-10-241-0/+1
| | | | | | | | | | | | | | | | | | | Summary: In ALR, 'ITlcase' should expect an opening curly. This is probably a forgotten edge case in ALR, since `maybe_layout` (which handles the non-ALR layout) already deals with the 'ITlcase' token properly. Test Plan: make TEST=T10453 && make TEST=T13087 Reviewers: bgamari, RyanGlScott Reviewed By: RyanGlScott Subscribers: RyanGlScott, rwbarton, carter GHC Trac Issues: #10453, #13087 Differential Revision: https://phabricator.haskell.org/D5236
* Parse the (!) type operator and allow type operators in existential contextVladislav Zavialov2018-10-041-19/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Improve the way `(!)`, `(~)`, and other type operators are handled in the parser, fixing two issues at once: 1. `(!)` can now be used as a type operator that respects fixity and precedence (#15457) 2. Existential context of a data constructor no longer needs parentheses (#15675) In addition to that, with this patch it is now trivial to adjust precedence of the `{-# UNPACK #-}` pragma, as suggested in https://ghc.haskell.org/trac/ghc/ticket/14761#comment:7 There was a small change to API Annotations. Before this patch, `(~)` was a strange special case that produced an annotation unlike any other type operator. After this patch, when `(~)` or `(!)` are used to specify strictness they produce AnnTilde and AnnBang annotations respectively, and when they are used as type operators, they produce no annotations. Test Plan: Validate Reviewers: simonpj, bgamari, alanz, RyanGlScott Reviewed By: RyanGlScott Subscribers: RyanGlScott, rwbarton, mpickering, carter GHC Trac Issues: #15457, #15675 Differential Revision: https://phabricator.haskell.org/D5180
* Fix #line pragmas in nested commentsBen Sklaroff2018-08-211-44/+122
| | | | | | | | | | | | | | | | | | | | | When parsing a nested comment or nested doc comment in the lexer, if we see a line starting with '#' we attempt to parse a #line pragma. This fixes how ghc handles output of the C preproccesor (-cpp flag) when the original source has C comments or pragmas inside haskell comments. Updates haddock submodule. Test Plan: ./validate Reviewers: bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie, carter GHC Trac Issues: #314 Differential Revision: https://phabricator.haskell.org/D4934
* Do not imply NoStarIsType by TypeOperators/TypeInTypeVladislav Zavialov2018-07-161-5/+0
| | | | | | | | | | | | | | | | | | | | | | Implementation of the "Embrace TypeInType" proposal was done according to the spec, which specified that TypeOperators must imply NoStarIsType. This implication was meant to prevent breakage and to be removed in 2 releases. However, compiling head.hackage has shown that this implication only magnified the breakage, so there is no reason to have it in the first place. To remain in compliance with the three-release policy, we add a workaround to define the (*) type operator even when -XStarIsType is on. Test Plan: ./validate Reviewers: bgamari, RyanGlScott, goldfire, phadej, hvr Reviewed By: bgamari, RyanGlScott Subscribers: harpocrates, rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4865
* Embrace -XTypeInType, add -XStarIsTypeVladislav Zavialov2018-06-141-41/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Implement the "Embrace Type :: Type" GHC proposal, .../ghc-proposals/blob/master/proposals/0020-no-type-in-type.rst GHC 8.0 included a major change to GHC's type system: the Type :: Type axiom. Though casual users were protected from this by hiding its features behind the -XTypeInType extension, all programs written in GHC 8+ have the axiom behind the scenes. In order to preserve backward compatibility, various legacy features were left unchanged. For example, with -XDataKinds but not -XTypeInType, GADTs could not be used in types. Now these restrictions are lifted and -XTypeInType becomes a redundant flag that will be eventually deprecated. * Incorporate the features currently in -XTypeInType into the -XPolyKinds and -XDataKinds extensions. * Introduce a new extension -XStarIsType to control how to parse * in code and whether to print it in error messages. Test Plan: Validate Reviewers: goldfire, hvr, bgamari, alanz, simonpj Reviewed By: goldfire, simonpj Subscribers: rwbarton, thomie, mpickering, carter GHC Trac Issues: #15195 Differential Revision: https://phabricator.haskell.org/D4748
* Introduce DerivingViaRyan Scott2018-06-041-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This implements the `DerivingVia` proposal put forth in https://github.com/ghc-proposals/ghc-proposals/pull/120. This introduces the `DerivingVia` deriving strategy. This is a generalization of `GeneralizedNewtypeDeriving` that permits the user to specify the type to `coerce` from. The major change in this patch is the introduction of the `ViaStrategy` constructor to `DerivStrategy`, which takes a type as a field. As a result, `DerivStrategy` is no longer a simple enumeration type, but rather something that must be renamed and typechecked. The process by which this is done is explained more thoroughly in section 3 of this paper ( https://www.kosmikus.org/DerivingVia/deriving-via-paper.pdf ), although I have inlined the relevant parts into Notes where possible. There are some knock-on changes as well. I took the opportunity to do some refactoring of code in `TcDeriv`, especially the `mkNewTypeEqn` function, since it was bundling all of the logic for (1) deriving instances for newtypes and (2) `GeneralizedNewtypeDeriving` into one huge broth. `DerivingVia` reuses much of part (2), so that was factored out as much as possible. Bumps the Haddock submodule. Test Plan: ./validate Reviewers: simonpj, bgamari, goldfire, alanz Subscribers: alanz, goldfire, rwbarton, thomie, mpickering, carter GHC Trac Issues: #15178 Differential Revision: https://phabricator.haskell.org/D4684
* Remove ~# from surface syntaxDavid Feuer2018-06-021-2/+0
| | | | | | | | | | | | | | | | | | | For some reason, it seems that the `ConstraintKinds` commit introduced `~#` into Haskell syntax, in a pretty broken manner. Unless and until we have an actual story for unboxed equality, it doesn't make sense to expose it. Moreover, the way it was donet was wrong enough and small enough that it will probably be easier to start over if we do that. Yank it out. Reviewers: bgamari, RyanGlScott Reviewed By: RyanGlScott Subscribers: RyanGlScott, rwbarton, thomie, mpickering, carter GHC Trac Issues: #15209 Differential Revision: https://phabricator.haskell.org/D4763
* vectorise: Put it out of its miseryBen Gamari2018-06-021-20/+3
| | | | | | | | | | | | | | | | | | | | | Poor DPH and its vectoriser have long been languishing; sadly it seems there is little chance that the effort will be rekindled. Every few years we discuss what to do with this mass of code and at least once we have agreed that it should be archived on a branch and removed from `master`. Here we do just that, eliminating heaps of dead code in the process. Here we drop the ParallelArrays extension, the vectoriser, and the `vector` and `primitive` submodules. Test Plan: Validate Reviewers: simonpj, simonmar, hvr, goldfire, alanz Reviewed By: simonmar Subscribers: goldfire, rwbarton, thomie, mpickering, carter Differential Revision: https://phabricator.haskell.org/D4761
* Implement BlockArguments (#10843)Takano Akio2018-01-311-9/+8
| | | | | | | | | | | | | | | | | | | | | | | | This patch implements the BlockArguments extension, as proposed at https://github.com/ghc-proposals/ghc-proposals/pull/90. It also fixes #10855 as a side-effect. This patch adds a large number of shift-reduce conflicts to the parser. All of them concern the ambiguity as to where constructs like `if` and `let` end. Fortunately they are resolved correctly by preferring shift. The patch is based on @gibiansky's ArgumentDo implementation (D1219). Test Plan: ./validate Reviewers: goldfire, bgamari, alanz, mpickering Reviewed By: bgamari, mpickering Subscribers: Wizek, dfeuer, gibiansky, rwbarton, thomie, mpickering, carter GHC Trac Issues: #10843, #10855 Differential Revision: https://phabricator.haskell.org/D4260
* Option for LINE pragmas to get lexed into tokensAlec Theriault2018-01-261-4/+31
| | | | | | | | | | | | | | | | This adds a parser-level switch to have 'LINE' and 'COLUMN' pragmas lexed into actual tokens (as opposed to updating the position information in the parser). 'lexTokenStream' is the only place where this option is enabled. Reviewers: bgamari, alexbiehl, mpickering Reviewed By: mpickering Subscribers: alanz, rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4336
* Implement underscores in numeric literals (NumericUnderscores extension)Takenobu Tani2018-01-211-39/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement the proposal of underscores in numeric literals. Underscores in numeric literals are simply ignored. The specification of the feature is available here: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/000 9-numeric-underscores.rst For a discussion of the various choices: https://github.com/ghc-proposals/ghc-proposals/pull/76 Implementation detail: * Added dynamic flag * `NumericUnderscores` extension flag is added for this feature. * Alex "Regular expression macros" in Lexer.x * Add `@numspc` (numeric spacer) macro to represent multiple underscores. * Modify `@decimal`, `@decimal`, `@binary`, `@octal`, `@hexadecimal`, `@exponent`, and `@bin_exponent` macros to include `@numspc`. * Alex "Rules" in Lexer.x * To be simpler, we have only the definitions with underscores. And then we have a separate function (`tok_integral` and `tok_frac`) that validates the literals. * Validation functions in Lexer.x * `tok_integral` and `tok_frac` functions validate whether contain underscores or not. If `NumericUnderscores` extensions are not enabled, check that there are no underscores. * `tok_frac` function is created by merging `strtoken` and `init_strtoken`. * `init_strtoken` is deleted. Because it is no longer used. * Remove underscores from target literal string * `parseUnsignedInteger`, `readRational__`, and `readHexRational} use the customized `span'` function to remove underscores. * Added Testcase * testcase for NumericUnderscores enabled. NumericUnderscores0.hs and NumericUnderscores1.hs * testcase for NumericUnderscores disabled. NoNumericUnderscores0.hs and NoNumericUnderscores1.hs * testcase to invalid pattern for NumericUnderscores enabled. NumericUnderscoresFail0.hs and NumericUnderscoresFail1.hs Test Plan: `validate` including the above testcase Reviewers: goldfire, bgamari Reviewed By: bgamari Subscribers: carter, rwbarton, thomie GHC Trac Issues: #14473 Differential Revision: https://phabricator.haskell.org/D4235
* Get rid of some stuttering in comments and docsGabor Greif2017-12-191-1/+1
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* Implement the basics of hex floating point literalsIavor Diatchki2017-11-021-4/+22
| | | | | | | | | | | | | | | | | | | | | | | Implement hexadecmial floating point literals. The digits of the mantissa are hexadecimal. The exponent is written in base 10, and the base for the exponentiation is 2. Hexadecimal literals look a lot like ordinary decimal literals, except that they use hexadecmial digits, and the exponent is written using `p` rather than `e`. The specification of the feature is available here: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0004-hexFloats.rst For a discussion of the various choices: https://github.com/ghc-proposals/ghc-proposals/pull/37 Reviewers: mpickering, goldfire, austin, bgamari, hvr Reviewed By: bgamari Subscribers: mpickering, thomie Differential Revision: https://phabricator.haskell.org/D3066
* Fix a bug in 'alexInputPrevChar'Alec Theriault2017-10-251-25/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The lexer hacks around unicode by squishing any character into a 'Word8' and then storing the actual character in its state. This happens at 'alexGetByte'. That is all and well, but we ought to be careful that the characters we retrieve via 'alexInputPrevChar' also fit this convention. In fact, #13986 exposes nicely what can go wrong: the regex in the left context of the type application rule uses the '$idchar' character set which relies on the unicode hack. However, a left context corresponds to a call to 'alexInputPrevChar', and we end up passing full blown unicode characters to '$idchar', despite it not being equipped to deal with these. Test Plan: Added a regression test case Reviewers: austin, bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie GHC Trac Issues: #13986 Differential Revision: https://phabricator.haskell.org/D4105
* compiler: introduce custom "GhcPrelude" PreludeHerbert Valerio Riedel2017-09-191-0/+2
| | | | | | | | | | | | | | | | | | This switches the compiler/ component to get compiled with -XNoImplicitPrelude and a `import GhcPrelude` is inserted in all modules. This is motivated by the upcoming "Prelude" re-export of `Semigroup((<>))` which would cause lots of name clashes in every modulewhich imports also `Outputable` Reviewers: austin, goldfire, bgamari, alanz, simonmar Reviewed By: bgamari Subscribers: goldfire, rwbarton, thomie, mpickering, bgamari Differential Revision: https://phabricator.haskell.org/D3989
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