#8220: Macros / functions for source location -------------------------------------+------------------------------------ Reporter: wojteknar | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by ezyang): You can do this using the C pre-processor: {{{ {-# LANGUAGE CPP #-} main = do print (__FILE__, __LINE__) }}} which is arguably the right place to do it. Is there any particular reason you want an ordinary function? A traditional function suffers from a severe modularity problem, because you can't use one of these functions in another function like "ASSERT"; it will report the line number of the assert definition and not the actual use-site of the assert; a pre- processor macro does not have this problem. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8220#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#8220: Macros / functions for source location -------------------------------------+------------------------------------ Reporter: wojteknar | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by simonpj): Also in Template Haskell you can get the source location of the splice. Thus {{{ ...$(do { loc <- location; ... }).... }}} But not (currently) the name of the enclosing function. It's not obvious exactly what you need here. The innermost enclosing function? Outermost? What if the splice is in a type declaration not a value declaration? In general, TH (rather than CPP) seems a nicer place to experiment. You could work on a design in collaboration with others, with worked-out use- cases. Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8220#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#8220: Macros / functions for source location -------------------------------------+------------------------------------ Reporter: wojteknar | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by wojteknar): On second thought, looking at my Parsec code, innermost enclosing function would be valuable, too. {{{ innerFunName, outerFunName :: String }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8220#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#8220: Macros / functions for source location -------------------------------------+------------------------------------ Reporter: wojteknar | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by literon): The extension in the branch https://github.com/sol/rewrite-with-location/ can help. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8220#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler