hscope (hackage): hscope is a partial cscope line oriented mode reimplementation for Haskell code. Currently it supports finding the definition and callers of the function, types. Also works searching for files and in files. See hscope --help for available options. Being cscope-compatible gives Vim integration for free. Use :set cscopeprg to configure hscope as cscope replacement for haskell files.
Keywords: bsd3|program|source-tools