diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/guix-cookbook.texi | 89 |
1 files changed, 48 insertions, 41 deletions
diff --git a/doc/guix-cookbook.texi b/doc/guix-cookbook.texi index c8d9beaa66..0a33efc73a 100644 --- a/doc/guix-cookbook.texi +++ b/doc/guix-cookbook.texi @@ -111,9 +111,10 @@ REPL} by running @code{guile} from the command line. Alternatively you can also run @code{guix environment --ad-hoc guile -- guile} if you'd rather not have Guile installed in your user profile. -In the following examples we use the @code{>} symbol to denote the REPL -prompt, that is, the line reserved for user input. @xref{Using Guile -Interactively,,, guile, GNU Guile Reference Manual}) for more details on the +In the following examples, lines show what you would type at the REPL; +lines starting with ``@result{}'' show evaluation results, while lines +starting with ``@print{}'' show things that get printed. @xref{Using Guile +Interactively,,, guile, GNU Guile Reference Manual}), for more details on the REPL. @itemize @@ -126,12 +127,15 @@ and @code{#f} stand for the Booleans ``true'' and ``false'', respectively. Examples of valid expressions: @lisp -> "Hello World!" "Hello World!" -> 17 +@result{} "Hello World!" + 17 -> (display (string-append "Hello " "Guix" "\n")) -"Hello Guix!" +@result{} 17 + +(display (string-append "Hello " "Guix" "\n")) +@print{} Hello Guix! +@result{} #<unspecified> @end lisp @item @@ -144,8 +148,8 @@ last evaluated expression as its return value. Anonymous functions are declared with the @code{lambda} term: @lisp -> (lambda (x) (* x x)) -#<procedure 120e348 at <unknown port>:24:0 (x)> +(lambda (x) (* x x)) +@result{} #<procedure 120e348 at <unknown port>:24:0 (x)> @end lisp The above procedure returns the square of its argument. Since everything is @@ -153,18 +157,18 @@ an expression, the @code{lambda} expression returns an anonymous procedure, which can in turn be applied to an argument: @lisp -> ((lambda (x) (* x x)) 3) -9 +((lambda (x) (* x x)) 3) +@result{} 9 @end lisp @item Anything can be assigned a global name with @code{define}: @lisp -> (define a 3) -> (define square (lambda (x) (* x x))) -> (square a) -9 +(define a 3) +(define square (lambda (x) (* x x))) +(square a) +@result{} 9 @end lisp @item @@ -178,8 +182,8 @@ Procedures can be defined more concisely with the following syntax: A list structure can be created with the @code{list} procedure: @lisp -> (list 2 a 5 7) -(2 3 5 7) +(list 2 a 5 7) +@result{} (2 3 5 7) @end lisp @item @@ -188,20 +192,21 @@ term is not called over the other terms. Thus it effectively returns a list of terms. @lisp -> '(display (string-append "Hello " "Guix" "\n")) -(display (string-append "Hello " "Guix" "\n")) -> '(2 a 5 7) -(2 a 5 7) +'(display (string-append "Hello " "Guix" "\n")) +@result{} (display (string-append "Hello " "Guix" "\n")) + +'(2 a 5 7) +@result{} (2 a 5 7) @end lisp @item -The @emph{quasiquote} disables evaluation of a parenthesized expression until +The @dfn{quasiquote} disables evaluation of a parenthesized expression until a comma re-enables it. Thus it provides us with fine-grained control over what is evaluated and what is not. @lisp -> `(2 a 5 7 (2 ,a 5 ,(+ a 4))) -(2 a 5 7 (2 3 5 7)) +`(2 a 5 7 (2 ,a 5 ,(+ a 4))) +@result{} (2 a 5 7 (2 3 5 7)) @end lisp Note that the above result is a list of mixed elements: numbers, symbols (here @@ -211,25 +216,27 @@ Note that the above result is a list of mixed elements: numbers, symbols (here Multiple variables can be named locally with @code{let}: @lisp -> (define x 10) -> (let ((x 2) - (y 3)) - (list x y)) -(2 3) -> x -10 -> y -ERROR: In procedure module-lookup: Unbound variable: y +(define x 10) +(let ((x 2) + (y 3)) + (list x y)) +@result{} (2 3) + +x +@result{} 10 + +y +@error{} In procedure module-lookup: Unbound variable: y @end lisp Use @code{let*} to allow later variable declarations to refer to earlier definitions. @lisp -> (let* ((x 2) - (y (* x 3))) - (list x y)) -(2 6) +(let* ((x 2) + (y (* x 3))) + (list x y)) +@result{} (2 6) @end lisp @item @@ -982,10 +989,10 @@ definition in @samp{$GUIX_CHECKOUT/guix/build/gnu-build-system.scm}: Or from the REPL: @lisp -> (add-to-load-path "/path/to/guix/checkout") -> ,module (guix build gnu-build-system) -> (map first %standard-phases) -(set-SOURCE-DATE-EPOCH set-paths install-locale unpack bootstrap patch-usr-bin-file patch-source-shebangs configure patch-generated-file-shebangs build check install patch-shebangs strip validate-runpath validate-documentation-location delete-info-dir-file patch-dot-desktop-files install-license-files reset-gzip-timestamps compress-documentation) +(add-to-load-path "/path/to/guix/checkout") +,use (guix build gnu-build-system) +(map first %standard-phases) +@result{} (set-SOURCE-DATE-EPOCH set-paths install-locale unpack bootstrap patch-usr-bin-file patch-source-shebangs configure patch-generated-file-shebangs build check install patch-shebangs strip validate-runpath validate-documentation-location delete-info-dir-file patch-dot-desktop-files install-license-files reset-gzip-timestamps compress-documentation) @end lisp If you want to know more about what happens during those phases, consult the |