guix-commits
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

03/11: doc: cookbook: Mention common SRFI-1 procedures.


From: guix-commits
Subject: 03/11: doc: cookbook: Mention common SRFI-1 procedures.
Date: Mon, 14 Aug 2023 18:34:37 -0400 (EDT)

civodul pushed a commit to branch master
in repository guix.

commit d20a7da4a38e96ded5bda1aab2df75f2eee2af85
Author: Ludovic Courtès <ludo@gnu.org>
AuthorDate: Mon Aug 14 15:08:00 2023 +0200

    doc: cookbook: Mention common SRFI-1 procedures.
    
    * doc/guix-cookbook.texi (A Scheme Crash Course): Add item about
    SRFI-1.
---
 doc/guix-cookbook.texi | 30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/doc/guix-cookbook.texi b/doc/guix-cookbook.texi
index 28303df37b..ee66dad7d9 100644
--- a/doc/guix-cookbook.texi
+++ b/doc/guix-cookbook.texi
@@ -192,7 +192,8 @@ rest are the arguments passed to the function.  Every 
function returns the
 last evaluated expression as its return value.
 
 @item
-Anonymous functions are declared with the @code{lambda} term:
+Anonymous functions---@dfn{procedures} in Scheme parlance---are declared
+with the @code{lambda} term:
 
 @lisp
 (lambda (x) (* x x))
@@ -208,6 +209,9 @@ which can in turn be applied to an argument:
 @result{} 9
 @end lisp
 
+Procedures are regular values just like numbers, strings, Booleans, and
+so on.
+
 @item
 Anything can be assigned a global name with @code{define}:
 
@@ -233,6 +237,30 @@ A list structure can be created with the @code{list} 
procedure:
 @result{} (2 3 5 7)
 @end lisp
 
+@item
+Standard procedures are provided by the @code{(srfi srfi-1)} module to
+create and process lists (@pxref{SRFI-1, list processing,, guile, GNU
+Guile Reference Manual}).  Here are some of the most useful ones in
+action:
+
+@lisp
+(use-modules (srfi srfi-1))  ;import list processing procedures
+
+(append (list 1 2) (list 3 4))
+@result{} (1 2 3 4)
+
+(map (lambda (x) (* x x)) (list 1 2 3 4))
+@result{} (1 4 9 16)
+
+(delete 3 (list 1 2 3 4))        @result{} (1 2 4)
+(filter odd? (list 1 2 3 4))     @result{} (1 3)
+(remove even? (list 1 2 3 4))    @result{} (1 3)
+(find number? (list "a" 42 "b")) @result{} 42
+@end lisp
+
+Notice how the first argument to @code{map}, @code{filter},
+@code{remove}, and @code{find} is a procedure!
+
 @item
 @cindex S-expression
 The @dfn{quote} disables evaluation of a parenthesized expression, also



reply via email to

[Prev in Thread] Current Thread [Next in Thread]