From eab369930516ece1d40658b891f4629d6f9ed8ac Mon Sep 17 00:00:00 2001 From: Jose Antonio Ortega Ruiz Date: Sun, 27 Jun 2010 01:43:32 +0200 Subject: A new tutorial bit --- doc/repl.texi | 85 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) create mode 100644 doc/repl.texi (limited to 'doc/repl.texi') diff --git a/doc/repl.texi b/doc/repl.texi new file mode 100644 index 0000000..03ed2ab --- /dev/null +++ b/doc/repl.texi @@ -0,0 +1,85 @@ +@node The REPL +@chapter The REPL +@anchor{quick-start} +If you've followed the indications in @ref{Setting it up}, your Emacs is +now ready to start playing. Otherwise, i'll wait for you: when you're +ready, just come back here and proceed to the following sections. + +@menu +* Starting the REPL:: +* First aids:: +* Switching contexts:: +@end menu + +@node Starting the REPL, First aids, The REPL, The REPL +@section Starting the REPL + +To start a Scheme REPL (meaning, a scheme process offering you a +Read-Eval-Print Loop), Geiser provides the generic interactive command +@command{run-geiser}. If you run it (via, as is customary in Emacs, +@kbd{M-x run-geiser}, you'll be saluted by a prompt asking which one of +the supported implementations you want to launch (yes, you can stop the +asking: see below). Tabbing for completion will offer you, as of this +writing, @code{guile} and @code{racket}. Just choose your poison, and a +new REPL buffer will pop-up. + +@image{img/repls} + +If all went according to plan, you'll be facing an +implementation-dependent banner, followed by an interactive prompt. +Going according to plan includes having the executable of the Scheme you +chose in your path. If that's not the case, you can tell Emacs where it +is by setting the variable @var{geiser--binary} to an appropriate +value. Returning to our REPL, the first thing to notice is that the +funny prompt is telling you your current module: its name is the part +just after the @@ sign (in Guile, that means @code{guile-user}, while +Racket's top namespace doesn't have a name; cf. @ref{Switching contexts} +below). Other than that, this is pretty much equivalent to having a +command-line interpreter in a terminal, with a bunch of add-ons that +we'll be reviewing below. You can start typing sexps right there: Geiser +will only dispatch them for evaluation when they're complete, and will +indent new lines properly until then. + +@node First aids, Switching contexts, Starting the REPL, The REPL +@section First aids + +@img{repl-menu, right} +A quick way of seeing what else Geiser's REPL can do for you, is to +display the corresponding entry up there in your menu bar. No, i don't +normally use menus either; but they can come in handy until you've +memorized Geiser's commands, as a learning device. And yes, i usually +run Emacs inside a terminal, but one can always use +@uref{http://www.emacswiki.org/emacs/LaCarte, La Carte} to access the +menus in a convenient enough fashion. + +Or just press @kbd{C-h m} and be done with that. + +Among the commands at your disposal, we find the familiar input +navigation keys, with a twist. By default, @kbd{M-p} and @kbd{M-n} are +bound to @i{matching} items in your input history. That is, they'll find +the previous or next sexp that start with the current input prefix +(defined as the text between the end of the prompt and your current +position, a.k.a. @dfn{point}, in the buffer). For going up and down the +list unconditionally, just use @kbd{C-c M-p} and @kbd{C-c M-n}. + +There are also a few commands to twiddle with the Scheme process. +@kbd{C-c C-q} will mercilessly kill it (but not before stowing your +history in the file system). A softer nuke is performed by @kbd{C-c +C-k}: some (rare, i promise) times, Geiser's REPL can get confused by +the input received from then underlying Scheme (specially if you have +multiple threads writing to the standard ports), and become +irresponsive; you can try this command to try to revive it without +killing the process. Finally, if bad comes to worst and the process is +dead, @kbd{C-c z} will restart it. + +The remaining commands are meatier, and deserve sections of their own. + +@node Switching contexts, , First aids, The REPL +@section Switching contexts +@comment node-name, next, previous, up + + +@c Local Variables: +@c mode: texinfo +@c TeX-master: "geiser" +@c End: -- cgit v1.2.3