
#12483: Improve parse error message on indentation mistake -------------------------------------+------------------------------------- Reporter: harendra | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Other Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Consider the following code fragment: {{{#!hs (ExecGhc, args) -> execCompiler "" args -- NOTE: this won't currently work for GHCJS, because it doesn't have -- a runghcjs binary. It probably will someday, though. (ExecRunGhc, args) -> }}} The last line is indented by one space but it is hard to notice esp when we looking at this along with a screenful of code and there are many comments between the two lines. When this code is compiled ghc throws the following error: {{{ Main.hs:745:40: error: parse error on input ‘->’ }}} I look at the error and then the code and wonder what is wrong with this code, there is nothing noticeably wrong. If ghc can provide some context I can easily make out where the problem is. ghc can perhaps tell me how the current expression is being parsed e.g. `(ExecRunGhc, args) ->` is being considered as a continuation of the expression on the previous line. I have run into this many times. The first time it was really frustrating. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12483 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler