[GHC] #10663: ghci ignores stuff after an import command and a semicolon
#10663: ghci ignores stuff after an import command and a semicolon -------------------------------------+------------------------------------- Reporter: rwbarton | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.10.1 Keywords: newcomer | Operating System: Unknown/Multiple Architecture: | Type of failure: GHC accepts Unknown/Multiple | invalid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- I can put a semicolon and then an expression or declaration after an import command in ghci, and the expression or declaration is simply ignored. {{{ rwbarton@morphism:~/ghc$ ghci-7.10.1 GHCi, version 7.10.1: http://www.haskell.org/ghc/ :? for help Prelude> import Data.List; x Prelude Data.List> }}} The stuff after the semicolon does have to parse, but then is discarded. Pretty confusing. It's especially confusing when using `ghc -e` {{{ rwbarton@morphism:~/ghc$ ghc-7.10.1 -e "import Data.List; sort [2,1]" rwbarton@morphism:~/ghc$ echo $? 0 }}} The command is wrong (in general you cannot give multiple commands separated by semicolons, you must use multiple `-e` options), but GHC fails to complain in any way and silently ignores the "second command". -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10663 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#10663: ghci ignores stuff after an import command and a semicolon -------------------------------------+------------------------------------- Reporter: rwbarton | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.10.1 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Changes (by osa1): * cc: osa1 (added) Comment: I'm trying to understand expected syntax here. It seems like I can only put expressions after the first semicolon, other GHCi commands don't work: {{{ λ:6> import Data.List; x; x + y λ:7> import Data.List; import Data.Char <no location info>: parse error in import declaration λ:8> let x = 10 λ:9> x; x; x <interactive>:9:2: parse error on input ‘;’ λ:10> let y = 10; y <interactive>:10:14: parse error (possibly incorrect indentation or mismatched brackets) λ:11> import Data.Char; x λ:12> }}} Also, I can't see anything related with semicolons in user manual "Using GHCi" section(https://downloads.haskell.org/~ghc/latest/docs/html/users_guide /interactive-evaluation.html) so it seems to me like this semicolon behavior is not intended and just a side effect of the used parser. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10663#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#10663: ghci ignores stuff after an import command and a semicolon -------------------------------------+------------------------------------- Reporter: rwbarton | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.10.1 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by rwbarton): Right, I think the expected behavior here (at least given the current behavior of ghci with respect to semicolons generally) is for `import Data.List; x` to be a syntax error of some kind. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10663#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#10663: ghci ignores stuff after an import command and a semicolon -------------------------------------+------------------------------------- Reporter: rwbarton | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.10.1 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by thomie): Fwiw, you can use the semicolon to set fixities: {{{
let add = (+); infixl 6 `add` }}}
-- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10663#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#10663: ghci ignores stuff after an import command and a semicolon -------------------------------------+------------------------------------- Reporter: rwbarton | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.10.1 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by rwbarton): That is a single `let`-command, `let { add = (+); infixl 6 `add` }`. You can write `do x; y` too, same logic. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10663#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#10663: ghci ignores stuff after an import command and a semicolon -------------------------------------+------------------------------------- Reporter: rwbarton | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.10.1 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by rwbarton): `type` (and presumably `data` and `class` and so on, everything which isn't real do-block syntax) has the same behavior as `import`, see #10704 for a real-life example. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10663#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#10663: ghci ignores stuff after an import command and a semicolon -------------------------------------+------------------------------------- Reporter: rwbarton | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.10.1 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D1726 Wiki Page: | -------------------------------------+------------------------------------- Changes (by rdragon): * differential: => Phab:D1726 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10663#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#10663: ghci ignores stuff after an import command and a semicolon
-------------------------------------+-------------------------------------
Reporter: rwbarton | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: GHCi | Version: 7.10.1
Resolution: | Keywords: newcomer
Operating System: Unknown/Multiple | Architecture:
Type of failure: GHC accepts | Unknown/Multiple
invalid program | Test Case:
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s): Phab:D1726
Wiki Page: |
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Comment (by Ben Gamari
#10663: ghci ignores stuff after an import command and a semicolon -------------------------------------+------------------------------------- Reporter: rwbarton | Owner: Type: bug | Status: merge Priority: normal | Milestone: Component: GHCi | Version: 7.10.1 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D1726 Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: new => merge -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10663#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#10663: ghci ignores stuff after an import command and a semicolon -------------------------------------+------------------------------------- Reporter: rwbarton | Owner: Type: bug | Status: closed Priority: normal | Milestone: 8.0.1 Component: GHCi | Version: 7.10.1 Resolution: fixed | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D1726 Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: merge => closed * resolution: => fixed * milestone: => 8.0.1 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10663#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
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