-*- mode: org -*-
* Overview

  Geiser is a generic Emacs/Scheme interaction mode, featuring an
  enhanced REPL and a set of minor modes improving Emacs' basic scheme
  major mode. The main functionalities provided are:

    - Evaluation of forms in the namespace of the current module.
    - Macro expansion.
    - File/module loading.
    - Namespace-aware identifier completion (including local bindings,
      names visible in the current module, and module names).
    - Autodoc: the echo area shows information about the signature of
      the procedure/macro around point automatically.
    - Jump to definition of identifier at point.
    - Access to documentation (including docstrings when the
      implementation provides it).
    - Listings of identifiers exported by a given module.
    - Listings of callers/callees of procedures.
    - Rudimentary support for debugging (list of
      evaluation/compilation error in an Emacs' compilation-mode
      buffer).
    - Support for inline images in schemes, such as Racket, that treat
      them as first order values.

   NOTE: if you're not in a hurry, Geiser's website
   (http://www.nongnu.org/geiser/) contains a nicer manual, also
   included in Geiser tarballs as a texinfo file (doc/geiser.info).

* Requirements

    Geiser needs Emacs 23.2 or better, and at least one of the
    supported scheme implementations:
      - Guile 2.2 or better.
      - PLT Racket 6.0 or better.
      - Chicken 4.8.0 or better.
      - MIT/GNU Scheme 9.1.1 or better.
      - Chibi 0.7.3 or better.
      - Chez 9.4 or better.

* Installation

  The easiest way is to use MELPA, and just type
  =M-x package-install RET geiser= inside emacs.

  Geiser can be used either directly from its uninstalled source tree
  or byte-compiled and installed after performing the standard
  configure/make/make install dance.  See the INSTALL file for more details.

** Chicken Addendum
    These steps are necessary to fully support Chicken Scheme, but are
    not required for any other scheme.

    - Install the necessary support eggs:

#+BEGIN_EXAMPLE
     $ chicken-install -s apropos chicken-doc
#+END_EXAMPLE

    - Update the Chicken documentation database:

#+BEGIN_EXAMPLE
     $ cd `csi -p '(chicken-home)'`
     $ curl http://3e8.org/pub/chicken-doc/chicken-doc-repo.tgz | sudo tar zx
#+END_EXAMPLE

* Basic configuration

  The loading invocations above install all supported Scheme
  implementations. You can list explicitly the ones that you want by
  setting the variable =geiser-active-implementations= *before* loading
  geiser.el. For instance:

#+BEGIN_SRC elisp
    (setq geiser-active-implementations '(chicken guile))
#+END_SRC

  On opening a scheme file, Geiser will try to guess its Scheme,
  defaulting to the first in the list. Use =C-c C-s= to select the
  implementation by hand (on a per file basis).

  Check the geiser customization group for some options with:

#+BEGIN_EXAMPLE
      M-x customize-group RET geiser RET
#+END_EXAMPLE

  In particular, customize =geiser-<impl>-binary=, which should point
  to an executable in your path.

  To start a REPL, =M-x geiser=.

** Completion with company-mode

    Geiser offers identifier and module name completion, bound to
    =M-TAB= and =M-`= respectively. Only names visible in the current
    module are offered.

    While that is cool and all, things are even better: if you have
    [[http://company-mode.github.io/][company mode]] installed, Geiser's completion will use it. Just
    require company-mode and, from then on, any new scheme buffer or
    REPL will use it.

* Quick key reference

** In Scheme buffers:

   |---------------+--------------------------------------------------|
   | =C-c C-s=     | Specify Scheme implementation for buffer         |
   | =C-c C-z=     | Switch to REPL                                   |
   | =C-c C-a=     | Switch to REPL and current module                |
   |---------------+--------------------------------------------------|
   | =M-.=         | Go to definition of identifier at point          |
   | =M-,=         | Go back to where M-. was last invoked            |
   | =C-c C-e m=   | Ask for a module and open its file               |
   | =C-c C-e C-l= | Add a given directory to Scheme's load path      |
   | =C-c C-e [=   | Toggle between () and [] for current form        |
   |---------------+--------------------------------------------------|
   | =C-M-x=       | Eval definition around point                     |
   | =C-c C-c=     | Eval definition around point                     |
   | =C-c M-e=     | Eval definition around point and switch to REPL  |
   | =C-x C-e=     | Eval sexp before point                           |
   | =C-c C-r=     | Eval region                                      |
   | =C-c M-r=     | Eval region and switch to REPL                   |
   | =C-c C-b=     | Eval buffer                                      |
   | =C-c M-b=     | Eval buffer and switch to REPL                   |
   |---------------+--------------------------------------------------|
   | =C-c C-m x=   | Macro-expand definition around point             |
   | =C-c C-m e=   | Macro-expand sexp before point                   |
   | =C-c C-m r=   | Macro-expand region                              |
   |---------------+--------------------------------------------------|
   | =C-c C-k=     | Compile and load current buffer                  |
   | =C-c C-l=     | Load scheme file                                 |
   | =C-u C-c C-k= | Compile and load current buffer, restarting REPL |
   |---------------+--------------------------------------------------|
   | =C-c C-d d=   | See documentation for identifier at point        |
   | =C-c C-d s=   | See short documentation for identifier at point  |
   | =C-c C-d i=   | Look up manual for identifier at point           |
   | =C-c C-d m=   | See a list of a module's exported identifiers    |
   | =C-c C-d a=   | Toggle autodoc mode                              |
   |---------------+--------------------------------------------------|
   | =C-c <=       | Show callers of procedure at point               |
   | =C-c >=       | Show callees of procedure at point               |
   |---------------+--------------------------------------------------|
   | =M-TAB=       | Complete identifier at point                     |
   | =M-`=, =C-.=  | Complete module name at point                    |
   | =TAB=         | Complete identifier at point or indent           |
   |               | (If =geiser-mode-smart-tab-p= is t)              |
   |---------------+--------------------------------------------------|

** In the REPL

    |----------------+----------------------------------------------------|
    | =C-c C-z=      | Start Scheme REPL, or jump to previous buffer      |
    | =C-c M-o=      | Clear scheme output                                |
    | =C-c C-q=      | Kill Scheme process                                |
    | =C-c C-l=      | Load scheme file                                   |
    | =C-c C-k=      | Nuke REPL: use it if the REPL becomes unresponsive |
    |----------------+----------------------------------------------------|
    | =M-.=          | Edit identifier at point                           |
    | =TAB=, =M-TAB= | Complete identifier at point                       |
    | =M-`=, =C-.=   | Complete module name at point                      |
    | =M-p=, =M-n=   | Prompt history, matching current prefix            |
    |----------------+----------------------------------------------------|
    | =C-c C-m=      | Set current module                                 |
    | =C-c C-i=      | Import module into current namespace               |
    | =C-c C-r=      | Add a given directory to scheme's load path        |
    |----------------+----------------------------------------------------|
    | =C-c C-d C-d=  | See documentation for symbol at point              |
    | =C-c C-d C-m=  | See documentation for module                       |
    | =C-c C-d C-a=  | Toggle autodoc mode                                |
    |----------------+----------------------------------------------------|

** In the documentation browser:

    |--------------+----------------------------------------------|
    | =f=          | Next page                                    |
    | =b=          | Previous page                                |
    |--------------+----------------------------------------------|
    | =TAB=, =n=   | Next link                                    |
    | =S-TAB=, =p= | Previous link                                |
    | =N=          | Next section                                 |
    | =P=          | Previous section                             |
    |--------------+----------------------------------------------|
    | =k=          | Kill current page and go to previous or next |
    | =g=, =r=     | Refresh page                                 |
    | =c=          | Clear browsing history                       |
    |--------------+----------------------------------------------|
    | =.=, =M-.=   | Edit identifier at point                     |
    | =z=          | Switch to REPL                               |
    |--------------+----------------------------------------------|
    | =q=          | Bury buffer                                  |
    |--------------+----------------------------------------------|

** In backtrace (evaluation/compile result) buffers:

    - =M-g n=, =M-g p=, =C-x `= for error navigation.
    - =q= to bury buffer.