| author |
Steve Losh <steve@stevelosh.com> |
| date |
Sat, 02 Dec 2017 12:48:50 -0500 |
| parents |
e07421f643fe |
| children |
5e8fb9b8a553 |
;;;; This file was automatically generated by Quickutil.
;;;; See http://quickutil.org for details.
;;;; To regenerate:
;;;; (qtlc:save-utils-as "quickutils.lisp" :utilities '(:CURRY :EXTREMUM :RCURRY :READ-FILE-INTO-STRING) :ensure-package T :package "ADVENT.QUICKUTILS")
(eval-when (:compile-toplevel :load-toplevel :execute)
(unless (find-package "ADVENT.QUICKUTILS")
(defpackage "ADVENT.QUICKUTILS"
(:documentation "Package that contains Quickutil utility functions.")
(:use #:cl))))
(in-package "ADVENT.QUICKUTILS")
(when (boundp '*utilities*)
(setf *utilities* (union *utilities* '(:MAKE-GENSYM-LIST :ENSURE-FUNCTION
:CURRY :EXTREMUM :RCURRY :ONCE-ONLY
:WITH-OPEN-FILE* :WITH-INPUT-FROM-FILE
:READ-FILE-INTO-STRING))))
(eval-when (:compile-toplevel :load-toplevel :execute)
(defun make-gensym-list (length &optional (x "G"))
"Returns a list of `length` gensyms, each generated as if with a call to `make-gensym`,
using the second (optional, defaulting to `\"G\"`) argument."
(let ((g (if (typep x '(integer 0)) x (string x))))
(loop repeat length
collect (gensym g))))
) ; eval-when
(eval-when (:compile-toplevel :load-toplevel :execute)
;;; To propagate return type and allow the compiler to eliminate the IF when
;;; it is known if the argument is function or not.
(declaim (inline ensure-function))
(declaim (ftype (function (t) (values function &optional))
ensure-function))
(defun ensure-function (function-designator)
"Returns the function designated by `function-designator`:
if `function-designator` is a function, it is returned, otherwise
it must be a function name and its `fdefinition` is returned."
(if (functionp function-designator)
function-designator
(fdefinition function-designator)))
) ; eval-when
(defun curry (function &rest arguments)
"Returns a function that applies `arguments` and the arguments
it is called with to `function`."
(declare (optimize (speed 3) (safety 1) (debug 1)))
(let ((fn (ensure-function function)))
(lambda (&rest more)
(declare (dynamic-extent more))
;; Using M-V-C we don't need to append the arguments.
(multiple-value-call fn (values-list arguments) (values-list more)))))
(define-compiler-macro curry (function &rest arguments)
(let ((curries (make-gensym-list (length arguments) "CURRY"))
(fun (gensym "FUN")))
`(let ((,fun (ensure-function ,function))
,@(mapcar #'list curries arguments))
(declare (optimize (speed 3) (safety 1) (debug 1)))
(lambda (&rest more)
(apply ,fun ,@curries more)))))
(defun extremum (sequence predicate &key key (start 0) end)
"Returns the element of `sequence` that would appear first if the subsequence
bounded by `start` and `end` was sorted using `predicate` and `key`.
`extremum` determines the relationship between two elements of `sequence` by using
the `predicate` function. `predicate` should return true if and only if the first
argument is strictly less than the second one (in some appropriate sense). Two
arguments `x` and `y` are considered to be equal if `(funcall predicate x y)`
and `(funcall predicate y x)` are both false.
The arguments to the `predicate` function are computed from elements of `sequence`
using the `key` function, if supplied. If `key` is not supplied or is `nil`, the
sequence element itself is used.
If `sequence` is empty, `nil` is returned."
(let* ((pred-fun (ensure-function predicate))
(key-fun (unless (or (not key) (eq key 'identity) (eq key #'identity))
(ensure-function key)))
(real-end (or end (length sequence))))
(cond ((> real-end start)
(if key-fun
(flet ((reduce-keys (a b)
(if (funcall pred-fun
(funcall key-fun a)
(funcall key-fun b))
a
b)))
(declare (dynamic-extent #'reduce-keys))
(reduce #'reduce-keys sequence :start start :end real-end))
(flet ((reduce-elts (a b)
(if (funcall pred-fun a b)
a
b)))
(declare (dynamic-extent #'reduce-elts))
(reduce #'reduce-elts sequence :start start :end real-end))))
((= real-end start)
nil)
(t
(error "Invalid bounding indexes for sequence of length ~S: ~S ~S, ~S ~S"
(length sequence)
:start start
:end end)))))
(defun rcurry (function &rest arguments)
"Returns a function that applies the arguments it is called
with and `arguments` to `function`."
(declare (optimize (speed 3) (safety 1) (debug 1)))
(let ((fn (ensure-function function)))
(lambda (&rest more)
(declare (dynamic-extent more))
(multiple-value-call fn (values-list more) (values-list arguments)))))
(defmacro once-only (specs &body forms)
"Evaluates `forms` with symbols specified in `specs` rebound to temporary
variables, ensuring that each initform is evaluated only once.
Each of `specs` must either be a symbol naming the variable to be rebound, or of
the form:
(symbol initform)
Bare symbols in `specs` are equivalent to
(symbol symbol)
Example:
(defmacro cons1 (x) (once-only (x) `(cons ,x ,x)))
(let ((y 0)) (cons1 (incf y))) => (1 . 1)"
(let ((gensyms (make-gensym-list (length specs) "ONCE-ONLY"))
(names-and-forms (mapcar (lambda (spec)
(etypecase spec
(list
(destructuring-bind (name form) spec
(cons name form)))
(symbol
(cons spec spec))))
specs)))
;; bind in user-macro
`(let ,(mapcar (lambda (g n) (list g `(gensym ,(string (car n)))))
gensyms names-and-forms)
;; bind in final expansion
`(let (,,@(mapcar (lambda (g n)
``(,,g ,,(cdr n)))
gensyms names-and-forms))
;; bind in user-macro
,(let ,(mapcar (lambda (n g) (list (car n) g))
names-and-forms gensyms)
,@forms)))))
(defmacro with-open-file* ((stream filespec &key direction element-type
if-exists if-does-not-exist external-format)
&body body)
"Just like `with-open-file`, but `nil` values in the keyword arguments mean to use
the default value specified for `open`."
(once-only (direction element-type if-exists if-does-not-exist external-format)
`(with-open-stream
(,stream (apply #'open ,filespec
(append
(when ,direction
(list :direction ,direction))
(when ,element-type
(list :element-type ,element-type))
(when ,if-exists
(list :if-exists ,if-exists))
(when ,if-does-not-exist
(list :if-does-not-exist ,if-does-not-exist))
(when ,external-format
(list :external-format ,external-format)))))
,@body)))
(defmacro with-input-from-file ((stream-name file-name &rest args
&key (direction nil direction-p)
&allow-other-keys)
&body body)
"Evaluate `body` with `stream-name` to an input stream on the file
`file-name`. `args` is sent as is to the call to `open` except `external-format`,
which is only sent to `with-open-file` when it's not `nil`."
(declare (ignore direction))
(when direction-p
(error "Can't specifiy :DIRECTION for WITH-INPUT-FROM-FILE."))
`(with-open-file* (,stream-name ,file-name :direction :input ,@args)
,@body))
(defun read-file-into-string (pathname &key (buffer-size 4096) external-format)
"Return the contents of the file denoted by `pathname` as a fresh string.
The `external-format` parameter will be passed directly to `with-open-file`
unless it's `nil`, which means the system default."
(with-input-from-file
(file-stream pathname :external-format external-format)
(let ((*print-pretty* nil))
(with-output-to-string (datum)
(let ((buffer (make-array buffer-size :element-type 'character)))
(loop
:for bytes-read = (read-sequence buffer file-stream)
:do (write-sequence buffer datum :start 0 :end bytes-read)
:while (= bytes-read buffer-size)))))))
(eval-when (:compile-toplevel :load-toplevel :execute)
(export '(curry extremum rcurry read-file-into-string)))
;;;; END OF quickutils.lisp ;;;;