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 contains a much nicer manual.
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.
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.
These steps are necessary to fully support Chicken Scheme, but are not required for any other scheme.
- Install the necessary support eggs:
$ chicken-install -s apropos srfi-18 srfi-1
These steps are necessary to fully support Chicken Scheme, but are not required for any other scheme.
- Install the necessary support eggs:
$ chicken-install -s apropos chicken-doc
- Update the Chicken documentation database:
$ cd `csi -p '(chicken-home)'` $ curl http://3e8.org/pub/chicken-doc/chicken-doc-repo.tgz | sudo tar zx
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:
(setq geiser-active-implementations '(chicken guile))
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:
M-x customize-group RET geiser RET
In particular, customize geiser-<impl>-binary
, which should point
to an executable in your path.
To start a REPL, M-x geiser
.
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 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.
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) |
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 |
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 |
M-g n
,M-g p
,C-x `
for error navigation.q
to bury buffer.