| author |
Steve Losh <steve@stevelosh.com> |
| date |
Thu, 04 Aug 2016 13:12:00 +0000 |
| parents |
50ab2f9c5b2f |
| children |
4199b9a26696 |
;;;; This file was automatically generated by Quickutil.
;;;; See http://quickutil.org for details.
;;;; To regenerate:
;;;; (qtlc:save-utils-as "quickutils.lisp" :utilities '(:WITH-GENSYMS :ONCE-ONLY :COMPOSE :CURRY :RCURRY :N-GRAMS :DEFINE-CONSTANT) :ensure-package T :package "SAND.QUICKUTILS")
(eval-when (:compile-toplevel :load-toplevel :execute)
(unless (find-package "SAND.QUICKUTILS")
(defpackage "SAND.QUICKUTILS"
(:documentation "Package that contains Quickutil utility functions.")
(:use #:cl))))
(in-package "SAND.QUICKUTILS")
(when (boundp '*utilities*)
(setf *utilities* (union *utilities* '(:STRING-DESIGNATOR :WITH-GENSYMS
:MAKE-GENSYM-LIST :ONCE-ONLY
:ENSURE-FUNCTION :COMPOSE :CURRY
:RCURRY :TAKE :N-GRAMS
:DEFINE-CONSTANT))))
(deftype string-designator ()
"A string designator type. A string designator is either a string, a symbol,
or a character."
`(or symbol string character))
(defmacro with-gensyms (names &body forms)
"Binds each variable named by a symbol in `names` to a unique symbol around
`forms`. Each of `names` must either be either a symbol, or of the form:
(symbol string-designator)
Bare symbols appearing in `names` are equivalent to:
(symbol symbol)
The string-designator is used as the argument to `gensym` when constructing the
unique symbol the named variable will be bound to."
`(let ,(mapcar (lambda (name)
(multiple-value-bind (symbol string)
(etypecase name
(symbol
(values name (symbol-name name)))
((cons symbol (cons string-designator null))
(values (first name) (string (second name)))))
`(,symbol (gensym ,string))))
names)
,@forms))
(defmacro with-unique-names (names &body forms)
"Binds each variable named by a symbol in `names` to a unique symbol around
`forms`. Each of `names` must either be either a symbol, or of the form:
(symbol string-designator)
Bare symbols appearing in `names` are equivalent to:
(symbol symbol)
The string-designator is used as the argument to `gensym` when constructing the
unique symbol the named variable will be bound to."
`(with-gensyms ,names ,@forms))
(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
(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)))))
(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 compose (function &rest more-functions)
"Returns a function composed of `function` and `more-functions` that applies its ;
arguments to to each in turn, starting from the rightmost of `more-functions`,
and then calling the next one with the primary value of the last."
(declare (optimize (speed 3) (safety 1) (debug 1)))
(reduce (lambda (f g)
(let ((f (ensure-function f))
(g (ensure-function g)))
(lambda (&rest arguments)
(declare (dynamic-extent arguments))
(funcall f (apply g arguments)))))
more-functions
:initial-value function))
(define-compiler-macro compose (function &rest more-functions)
(labels ((compose-1 (funs)
(if (cdr funs)
`(funcall ,(car funs) ,(compose-1 (cdr funs)))
`(apply ,(car funs) arguments))))
(let* ((args (cons function more-functions))
(funs (make-gensym-list (length args) "COMPOSE")))
`(let ,(loop for f in funs for arg in args
collect `(,f (ensure-function ,arg)))
(declare (optimize (speed 3) (safety 1) (debug 1)))
(lambda (&rest arguments)
(declare (dynamic-extent arguments))
,(compose-1 funs))))))
(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 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)))))
(defun take (n sequence)
"Take the first `n` elements from `sequence`."
(subseq sequence 0 n))
(defun n-grams (n sequence)
"Find all `n`-grams of the sequence `sequence`."
(assert (and (plusp n)
(<= n (length sequence))))
(etypecase sequence
;; Lists
(list (loop :repeat (1+ (- (length sequence) n))
:for seq :on sequence
:collect (take n seq)))
;; General sequences
(sequence (loop :for i :to (- (length sequence) n)
:collect (subseq sequence i (+ i n))))))
(defun %reevaluate-constant (name value test)
(if (not (boundp name))
value
(let ((old (symbol-value name))
(new value))
(if (not (constantp name))
(prog1 new
(cerror "Try to redefine the variable as a constant."
"~@<~S is an already bound non-constant variable ~
whose value is ~S.~:@>" name old))
(if (funcall test old new)
old
(restart-case
(error "~@<~S is an already defined constant whose value ~
~S is not equal to the provided initial value ~S ~
under ~S.~:@>" name old new test)
(ignore ()
:report "Retain the current value."
old)
(continue ()
:report "Try to redefine the constant."
new)))))))
(defmacro define-constant (name initial-value &key (test ''eql) documentation)
"Ensures that the global variable named by `name` is a constant with a value
that is equal under `test` to the result of evaluating `initial-value`. `test` is a
function designator that defaults to `eql`. If `documentation` is given, it
becomes the documentation string of the constant.
Signals an error if `name` is already a bound non-constant variable.
Signals an error if `name` is already a constant variable whose value is not
equal under `test` to result of evaluating `initial-value`."
`(defconstant ,name (%reevaluate-constant ',name ,initial-value ,test)
,@(when documentation `(,documentation))))
(eval-when (:compile-toplevel :load-toplevel :execute)
(export '(with-gensyms with-unique-names once-only compose curry rcurry
n-grams define-constant)))
;;;; END OF quickutils.lisp ;;;;