Clean up formatting
author |
Steve Losh <steve@stevelosh.com> |
date |
Tue, 05 Jul 2016 16:53:58 +0000 |
parents |
89df9abc00e5 |
children |
410acaae0c14 |
(in-package #:bones.utils)
(defmacro push-if-new (thing place
&environment env
&key key (test '#'eql))
"Push `thing` into the list at `place` if it's not already there.
Returns whether `thing` was actually pushed. This function is basically
`pushnew` except for the return value.
"
(multiple-value-bind (temps exprs stores store-expr access-expr)
(get-setf-expansion place env)
(declare (ignore stores store-expr))
(with-gensyms (current result)
`(let* (,@(zip temps exprs)
(,current ,access-expr)
(,result (pushnew ,thing ,place :key ,key :test ,test)))
(not (eql ,current ,result))))))
(defun invert-hash-table (hash-table)
"Jesus christ don't actually use this for anything but debugging.
Inverts the keys/values of a `hash-table`.
"
(alist-to-hash-table
(loop :for k :being :the :hash-keys :of hash-table
:using (hash-value v)
:collect (list v k))))
(defmacro repeat (n &body body)
"Repeat `body` `n` times."
`(dotimes (,(gensym) ,n)
,@body))
(defun hex (d)
(format nil "~X" d))
(defmacro when-let ((symbol value) &body body)
"Bind `value` to `symbol` and execute `body` if the value was not `nil`."
`(let ((,symbol ,value))
(when ,symbol ,@body)))
(defun unique-items (list)
"Return a list of the items that appear exactly once in `list`."
(loop
:with once = nil
:with seen = nil
:for item :in list
:do (if (member item seen)
(when (member item once)
(setf once (delete item once)))
(progn (push item seen)
(push item once)))
:finally (return once)))
(defmacro dis (arglist &body body)
"Disassemble the code generated for a `lambda*` with `arglist` and `body`.
It will also spew compiler notes so you can see why the garbage box isn't
doing what you think it should be doing.
"
`(->> '(lambda* ,arglist
(declare (optimize speed))
,@body)
macroexpand-1
(compile nil)
disassemble))
(defmacro recursively (bindings &body body)
"Execute body recursively, like Clojure's `loop`/`recur`.
`bindings` should contain a list of symbols and (optional) default values.
In `body`, `recur` will be bound to the function for recurring.
Example:
(defun length (some-list)
(recursively ((list some-list) (n 0))
(if (null list)
n
(recur (cdr list) (1+ n)))))
"
(flet ((extract-var (binding)
(if (atom binding) binding (first binding)))
(extract-val (binding)
(if (atom binding) nil (second binding))))
`(labels ((recur ,(mapcar #'extract-var bindings)
,@body))
(recur ,@(mapcar #'extract-val bindings)))))