Node:Value History, Next:Pretty Printing, Previous:Readline Support, Up:Top
Another module which makes command line usage more convenient is
(ice-9 history)
. This module will change the REPL so that each
value which is evaluated and printed will be remembered under a name
constructed from the dollar character ($
) and the number of the
evaluated expression.
Consider an example session.
guile> (use-modules (ice-9 history)) guile> 1 $1 = 1 guile> (+ $1 $1) $2 = 2 guile> (* $2 $2) $3 = 4
After loading the value history module (ice-9 history)
, one
(trivial) expression is evaluated. The result is stored into the
variable $1
. This fact is indicated by the output $1 =
,
which is also caused by (ice-9 history)
. In the next line, this
variable is used two times, to produce the value $2
, which in
turn is used in the calculation for $3
.