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| -rw-r--r-- | README.org | 109 | ||||
| -rw-r--r-- | macros.lisp | 2 | ||||
| -rw-r--r-- | package.lisp | 3 | ||||
| -rw-r--r-- | reader-macros.lisp | 1 |
4 files changed, 111 insertions, 4 deletions
diff --git a/README.org b/README.org new file mode 100644 index 0000000..14e3086 --- /dev/null +++ b/README.org @@ -0,0 +1,109 @@ +* lambda-riffs + +ALPHA QUALITY -- USE AT YOUR OWN RISK + +A simple "one file" system that adds a reader macro for quick lambda +riffing. + +** Examples and Use + +To use the system, simply load it. It adds a single reader macro to +you lisp system. + +If this system has any actual users, and if those users are +dissatisfied with the alteration of the global readtable, let me know +and I can try adapting this for use with named-readtables. + +*** Normal Use + +As normally used, lambda-riffs lets you make quick anonymous +functions. There is a special syntax for making variables that start +with $, for example `$x` or `$my-var` + +Here is a basic example + + #+begin_src lisp :results verbatim + + (let ((xs (list 1 2 3 4 5 6))) + (remove-if-not #$(member $x xs) + (loop repeat 20 collect (random 10)))) + + #+end_src + + #+RESULTS: + : (3 1 6 1 4 2 4 6 4 3 5 1 5 3) + +the =#$= syntax is a reader macro dispatch sequence. An symbol that +begins with =$= inside a form that begins with =#$= will be treated as +a parameter of the function being defined. + +#+begin_src lisp :results verbatim + +(list (funcall #$(list $x $y) 1 2) + (funcall #$(list $x $x $x) 10)) + +#+end_src + +#+RESULTS: +: ((1 2) (10 10 10)) + + +*** Numbered Arguments + +Examples of numbered arguments: + +- =$1= , =$2= +- =$1-with-a-name= , =$2another-name= + +I.e. numbered arguments begin $ and are followed by an integer, and +then any normal variable name characters. + +Their effect is to explicitly specify the order of the parameters +being defined. Here is ane example: + +#+begin_src lisp :results verbatim + +(funcall #$(list $2-symb $1-symb) 'second 'first) + +#+end_src + +#+RESULTS: +: (FIRST SECOND) + +In the above ='second= is passed in as the first argument, and +='first= is passed as the second argument. + +Interestingly the numbers do not have to be sequentail, they are +merely sorted in ascending order: + +#+begin_src lisp :results verbatim + +(funcall #$(list $10 $2 $4) :two :four :ten) + +#+end_src + +#+RESULTS: +: (:TEN :TWO :FOUR) + +*** Nested Forms + +You can nest forms by adding an additional $ to the +dispatch. Variables of nested forms must include the same number of $ +characters as there are in the dispatch form. + +This is easer to understand through example: + +#+begin_src lisp :results verbatim + +;; map over a list of lists, subtracting 9 from any member of a list +;; that is greater than 9 + +(mapcar #$(mapcar + #$$(if (> $$x 9) (- $$x 9) $$x) ; our nested form + $digit-list) + '((1 2 3 4 5 6 7 8 9) + (10 11 12 12 14 15 16 17 18))) +#+end_src + +#+RESULTS: +: ((1 2 3 4 5 6 7 8 9) (1 2 3 3 5 6 7 8 9)) diff --git a/macros.lisp b/macros.lisp index b9d728b..fa93bc5 100644 --- a/macros.lisp +++ b/macros.lisp @@ -17,7 +17,7 @@ (elt (symbol-name symbol) (length prefix))))) - (set-macro-character + (set-dispatch-macro-character #\# #\$ (lambda (stream subchar infix) (declare (ignore subchar infix)) diff --git a/package.lisp b/package.lisp index 6239056..dcadede 100644 --- a/package.lisp +++ b/package.lisp @@ -1,5 +1,4 @@ ;;;; package.lisp (defpackage #:lambda-riffs - (:use #:cl) - (:export #:$)) + (:use #:cl)) diff --git a/reader-macros.lisp b/reader-macros.lisp deleted file mode 100644 index 8b13789..0000000 --- a/reader-macros.lisp +++ /dev/null @@ -1 +0,0 @@ - |