inf-haskell

doc/haskell-mode.texi

@@ -67,13 +67,13 @@ interpreter (e.g. GHCi).
 * Module templates::                     Module templates
 * Declaration scanning::                 How to navigate in a source file
 * Compilation::                          How to compile
-* Inferior Haskell interpreter::         How to interact with GHCi (1)
-* Interactive Haskell::                  How to interact with GHCi (2)
+* Interactive Haskell::                  How to interact with GHCi
 * Editing Cabal files::                  Cabal support
 * Browsing Haddocks::                    Using @code{w3m} to browse documentation
 * Spell checking strings and comments::  Using @code{flyspell-prog-mode}
 * Aligning code::                        Aligning code using @code{align-regexp}
 * Rectangular commands::                 Manage indentation manually
+* REPL::                                 GHCi REPL
 * Collapsing Haskell code::              View more code on screen
 * Getting Help and Reporting Bugs::      How to improve Haskell Mode
 * Concept index::                        Index of Haskell Mode concepts
@@ -1148,49 +1148,6 @@ temporarily by invoking @code{haskell-compile} with a prefix argument
 same customized compile command, invoke @code{recompile} (bound to
 @kbd{g}) inside the @samp{*haskell-compilation*} buffer.
 
-@node Inferior Haskell interpreter
-@chapter Inferior Haskell interpreter
-
-@findex inferior-haskell-find-definition
-@findex inferior-haskell-find-haddock
-@findex inferior-haskell-info
-@findex inferior-haskell-load-and-run
-@findex inferior-haskell-load-file
-@findex inferior-haskell-mode
-@findex inferior-haskell-reload-file
-@findex inferior-haskell-start-process
-@findex inferior-haskell-type
-@vindex haskell-program-name
-@vindex inferior-haskell-mode-hook
-
-The major mode @code{inferior-haskell-mode} provides support for
-interacting with an inferior Haskell process based on
-@code{comint-mode}.
-
-By default the @code{haskell-mode-map} keymap is setup to use this mode:
-
-@table @kbd
-@item C-c C-z
-is bound to @code{switch-to-haskell}
-@item C-c C-b
-is bound to @code{switch-to-haskell}
-@item C-c C-l
-is bound to @code{inferior-haskell-load-file}
-@item C-c C-t
-is bound to @code{inferior-haskell-type}
-@item C-c C-i
-is bound to @code{inferior-haskell-info}
-@end table
-
-The Haskell interpreter used by the inferior Haskell mode is
-auto-detected by default, but is customizable via the
-@code{haskell-program-name} variable.
-
-Currently, GHCi and Hugs are support as Haskell interpreter.
-
-TODO/WRITEME
-@c write about supported features
-
 @node Interactive Haskell
 @chapter Interactive Haskell
 
@@ -2593,6 +2550,128 @@ This will insert the contents of the last killed rectangle.
 As with all Emacs modifier combos, you can type @kbd{C-x r C-h} to find
 out what keys are bound beginning with the @kbd{C-x r} prefix.
 
+@node REPL
+@chapter Using GHCi REPL within Emacs
+
+To start the REPL you can run one of the following:
+
+@itemize
+@item @kbd{M-x run-haskell}
+@item @kbd{M-x switch-to-haskell}
+@end itemize
+
+This repl works with @uref{https://www.emacswiki.org/emacs/ComintMode, Comint}.
+So you will feel at home if you are already using @kbd{M-x Shell} or @kbd{M-x ielm}.
+
+@code{Inf-Haskell} is a Major mode for running GHCi, with comint.
+
+Important key bindings in @code{Inf-haskell}:
+
+@table @kbd
+@item RET
+invokes @kbd{comint-send-input}. Sends the input to the GHCi process, evaluates
+the line and returns the output.
+
+@item C-d or <delete>
+deletes the forward character
+
+@item <C-up> or M-p
+invokes @kbd{comint-previous-input}. Cycle backwards through input history,
+saving input.
+
+@item <C-down> or M-n
+invokes @kbd{comint-next-input}. Cycle forwards through input history.
+
+@item C-c C-c
+invokes @kbd{comint-interrupt-subjob}. Sends KeyboardInterrupt signal.
+
+@item C-c C-\
+invokes @kbd{comint-quit-subjob}. Sends KeyboardInterrupt signal.
+
+@item C-c C-z
+invokes @kbd{comint-stop-subjob}. Kills the GHCi process.
+
+@item C-c M-r
+invokes @kbd{comint-previous-matching-input-from-input}. If you are familiar
+with @kbd{C-r} in bash. This is the same as that. Searches backwards through
+input history for match for current input.
+
+@item C-c M-s
+invokes @kbd{comint-next-matching-input-from-input}. Searches forwards through
+input history for match for current input.
+
+@item C-c C-l
+invokes @kbd{comint-dynamic-list-input-ring}. Displays a list of recent inputs
+entered into the current buffer.
+
+@item C-c M-o
+invokes @kbd{comint-clear-buffer}. Clears the buffer (Only with Emacs 25.X and above)
+
+@item C-c C-n
+invokes @kbd{comint-next-prompt}. Goes to the start of the previous REPL prompt.
+
+@item C-c C-p
+invokes @kbd{comint-previous-prompt}. Goes to the start of the next REPL prompt.
+
+@item C-c C-o
+invokes @kbd{comint-delete-output}. Clears the output of the most recently evaluated
+expression.
+
+@item C-c C-e
+invokes @kbd{comint-show-maximum-output}. Moves the point to the end of the buffer.
+
+@item C-c C-u
+invokes @kbd{comint-kill-input}. Kills backward, the line at point. (Use this when you have typed in an expression into the prompt
+but you dont want to evaluate it.)
+
+@item C-c C-w
+invokes @kbd{backward-kill-word}. Kills backward, the word at point
+
+@item C-c C-s
+invokes @kbd{comint-write-output}. Write output from interpreter since last
+input to FILENAME. Any prompt at the end of the output is not written.
+@end table
+
+@section Relevant defcustoms:
+
+@multitable @columnfractions .40 .20 .40
+@headitem Interpreter (defcustom) @tab Default Value @tab Possible Values
+@item @code{haskell-process-type} @tab @code{'auto} @tab @code{'stack-ghci, 'cabal-repl, 'ghci, 'auto}
+@item @code{inferior-haskell-hook} @tab @code{nil} @tab -
+@item @code{haskell-process-path-ghci} @tab @code{ghci} @tab -
+@item @code{haskell-process-args-ghci} @tab @code{-ferror-spans} @tab -
+@item @code{haskell-process-path-cabal} @tab @code{cabal} @tab -
+@item @code{haskell-process-args-cabal-repl} @tab @code{--ghc-option=-ferror-spans} @tab -
+@item @code{haskell-process-path-stack} @tab @code{stack} @tab -
+@item @code{haskell-process-args-stack-ghci} @tab @code{--ghci-options=-ferror-spans --no-build --no-load} @tab -
+@end multitable
+
+@section More on @code{haskell-process-type}
+
+The Haskell interpreter used by @code{Inf-Haskell} is auto-detected by default,
+but is customizable with defcustom @code{haskell-process-type}. The values
+recognized by it are (default is 'auto):
+
+@itemize
+@item @code{'stack-ghci}
+@item @code{'cabal-repl}
+@item @code{'ghci}
+@item @code{'auto}
+@end itemize
+
+if the @code{haskell-process-type} is @code{'auto}, the directories are searched for
+@code{cabal.sandbox.config} or @code{stack.yaml} or  @code{*.cabal} file.
+If the file is present, then appropriate process is started.
+
+When @code{cabal.sandbox.config} is found @code{haskell-process-type} is @code{'cabal-repl}.
+Similarly, when @code{stack.yaml} is found @code{haskell-process-type} is @code{'stack-ghci}.
+Similarly, when @code{xyz.cabal} is found @code{haskell-process-type} is @code{'cabal-repl}.
+When nothing is found @code{haskell-process-type} is @code{'ghci}. When more than one
+file such as @code{cabal.sandbox.config} and @code{stack.yaml} are found the following
+preference is followed.
+
+@code{cabal.sandbox.config} > @code{stack.yaml} >  @code{*.cabal}
+
 @node Collapsing Haskell code
 @chapter Collapsing Haskell code
 

haskell-customize.el

@@ -64,7 +64,11 @@ be located, then stack-ghci will be used.
 Otherwise if there's a *.cabal file, cabal-repl will be used.
 
 If none of the above apply, ghci will be used."
-  :type '(choice (const auto) (const ghci) (const cabal-repl) (const stack-ghci) (const cabal-new-repl))
+  :type '(choice (const auto)
+                 (const ghci)
+                 (const cabal-repl)
+                 (const stack-ghci)
+                 (const cabal-new-repl))
   :group 'haskell-interactive)
 
 (defcustom haskell-process-wrapper-function
@@ -177,6 +181,22 @@ pass additional flags to `ghc'."
   :group 'haskell-interactive
   :type '(repeat (string :tag "Argument")))
 
+(defcustom haskell-process-path-ghc
+  "ghc"
+  "Path for The Glorious Glasgow Haskell Compiler")
+
+(defcustom haskell-process-args-ghc
+  "--make -ferror-spans -Wall -fforce-recomp"
+  "Any arguments for starting ghc.")
+
+(defcustom haskell-process-args-cabal-build
+  "--ghc-options=\"-ferror-spans -Wall -fforce-recomp\""
+  "Arguments while doing cabal build.")
+
+(defcustom haskell-process-args-stack-build
+  "--ghc-options=\"-ferror-spans -Wall\""
+  "Additional arguments for `stack build' invocation.")
+
 (defcustom haskell-process-do-cabal-format-string
   ":!cd %s && %s"
   "The way to run cabal comands. It takes two arguments -- the directory and the command.
@@ -415,22 +435,43 @@ imports."
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Accessor functions
 
+(defvar inferior-haskell-root-dir nil
+  "The path which is considered as project root, this is determined by the
+presence of a *.cabal file or stack.yaml file or something similar.")
+
 (defun haskell-process-type ()
-  "Return `haskell-process-type', or a guess if that variable is 'auto."
-  (if (eq 'auto haskell-process-type)
-      (cond
-       ;; User has explicitly initialized this project with cabal
-       ((locate-dominating-file default-directory "cabal.sandbox.config")
-        'cabal-repl)
-       ((and (locate-dominating-file default-directory "stack.yaml")
-             (executable-find "stack"))
-        'stack-ghci)
-       ((locate-dominating-file
-         default-directory
-         (lambda (d)
-           (cl-find-if (lambda (f) (string-match-p ".\\.cabal\\'" f)) (directory-files d))))
-        'cabal-repl)
-       (t 'ghci))
-    haskell-process-type))
+  "Return `haskell-process-type', or a guess if that variable is 'auto.
+This function also sets the `inferior-haskell-root-dir'"
+  (let ((cabal-sandbox (locate-dominating-file default-directory
+                                               "cabal.sandbox.config"))
+        (stack         (locate-dominating-file default-directory
+                                               "stack.yaml"))
+        (cabal         (locate-dominating-file default-directory
+                                               (lambda (d)
+                                                 (cl-find-if
+                                                  (lambda (f)
+                                                    (string-match-p ".\\.cabal\\'" f))
+                                                  (directory-files d))))))
+    (if (eq 'auto haskell-process-type)
+        (cond
+         ;; User has explicitly initialized this project with cabal
+         ((and cabal-sandbox
+               (executable-find "cabal"))
+          (setq inferior-haskell-root-dir cabal-sandbox)
+          'cabal-repl)
+         ((and stack
+               (executable-find "stack"))
+          (setq inferior-haskell-root-dir stack)
+          'stack-ghci)
+         ((and cabal
+               (executable-find "cabal"))
+          (setq inferior-haskell-root-dir cabal)
+          'cabal-repl)
+         ((executable-find "ghc")
+          (setq inferior-haskell-root-dir default-directory)
+          'ghci)
+         (t
+          (error "Could not find any installation of GHC.")))
+      haskell-process-type)))
 
 (provide 'haskell-customize)

haskell-doc.el

@@ -1848,6 +1848,14 @@ This function switches to and potentially loads many buffers."
         ;; return the result
         doc ))))
 
+(defun inferior-haskell-kind (sym)
+  "Find the kind of SYM with `:kind' ghci feature."
+  (inferior-haskell-get-result (format ":kind %s" sym)))
+
+(defun inferior-haskell-type (sym)
+  "Find the type of SYM with `:type' ghci feature."
+  (inferior-haskell-get-result (format ":type (%s)" sym)))
+
 (provide 'haskell-doc)
 
 ;;; haskell-doc.el ends here