| author |
Steve Losh <steve@stevelosh.com> |
| date |
Sun, 15 May 2016 17:46:49 +0000 |
| parents |
564d579c018b |
| children |
15245c6a668a |
;;;; This file was automatically generated by Quickutil.
;;;; See http://quickutil.org for details.
;;;; To regenerate:
;;;; (qtlc:save-utils-as "quickutils.lisp" :utilities '(:DEFINE-CONSTANT :SWITCH :WHILE :ENSURE-BOOLEAN :WITH-GENSYMS :ONCE-ONLY :IOTA :CURRY :RCURRY :COMPOSE :N-GRAMS) :ensure-package T :package "CODING-MATH.QUICKUTILS")
(eval-when (:compile-toplevel :load-toplevel :execute)
(unless (find-package "CODING-MATH.QUICKUTILS")
(defpackage "CODING-MATH.QUICKUTILS"
(:documentation "Package that contains Quickutil utility functions.")
(:use #:cl))))
(in-package "CODING-MATH.QUICKUTILS")
(when (boundp '*utilities*)
(setf *utilities* (union *utilities* '(:DEFINE-CONSTANT :STRING-DESIGNATOR
:WITH-GENSYMS :EXTRACT-FUNCTION-NAME
:SWITCH :UNTIL :WHILE :ENSURE-BOOLEAN
:MAKE-GENSYM-LIST :ONCE-ONLY :IOTA
:ENSURE-FUNCTION :CURRY :RCURRY
:COMPOSE :TAKE :N-GRAMS))))
(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))))
(deftype string-designator ()
"A string designator type. A string designator is either a string, a symbol,
or a character."
`(or symbol string character))
(eval-when (:compile-toplevel :load-toplevel :execute)
(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
(eval-when (:compile-toplevel :load-toplevel :execute)
(defun extract-function-name (spec)
"Useful for macros that want to mimic the functional interface for functions
like `#'eq` and `'eq`."
(if (and (consp spec)
(member (first spec) '(quote function)))
(second spec)
spec))
) ; eval-when
(eval-when (:compile-toplevel :load-toplevel :execute)
(defun generate-switch-body (whole object clauses test key &optional default)
(with-gensyms (value)
(setf test (extract-function-name test))
(setf key (extract-function-name key))
(when (and (consp default)
(member (first default) '(error cerror)))
(setf default `(,@default "No keys match in SWITCH. Testing against ~S with ~S."
,value ',test)))
`(let ((,value (,key ,object)))
(cond ,@(mapcar (lambda (clause)
(if (member (first clause) '(t otherwise))
(progn
(when default
(error "Multiple default clauses or illegal use of a default clause in ~S."
whole))
(setf default `(progn ,@(rest clause)))
'(()))
(destructuring-bind (key-form &body forms) clause
`((,test ,value ,key-form)
,@forms))))
clauses)
(t ,default))))))
(defmacro switch (&whole whole (object &key (test 'eql) (key 'identity))
&body clauses)
"Evaluates first matching clause, returning its values, or evaluates and
returns the values of `default` if no keys match."
(generate-switch-body whole object clauses test key))
(defmacro eswitch (&whole whole (object &key (test 'eql) (key 'identity))
&body clauses)
"Like `switch`, but signals an error if no key matches."
(generate-switch-body whole object clauses test key '(error)))
(defmacro cswitch (&whole whole (object &key (test 'eql) (key 'identity))
&body clauses)
"Like `switch`, but signals a continuable error if no key matches."
(generate-switch-body whole object clauses test key '(cerror "Return NIL from CSWITCH.")))
(defmacro until (expression &body body)
"Executes `body` until `expression` is true."
`(do ()
(,expression)
,@body))
(defmacro while (expression &body body)
"Executes `body` while `expression` is true."
`(until (not ,expression)
,@body))
(defun ensure-boolean (x)
"Convert `x` into a Boolean value."
(and x t))
(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)))))
(declaim (inline iota))
(defun iota (n &key (start 0) (step 1))
"Return a list of `n` numbers, starting from `start` (with numeric contagion
from `step` applied), each consequtive number being the sum of the previous one
and `step`. `start` defaults to `0` and `step` to `1`.
Examples:
(iota 4) => (0 1 2 3)
(iota 3 :start 1 :step 1.0) => (1.0 2.0 3.0)
(iota 3 :start -1 :step -1/2) => (-1 -3/2 -2)"
(declare (type (integer 0) n) (number start step))
(loop repeat n
;; KLUDGE: get numeric contagion right for the first element too
for i = (+ (- (+ start step) step)) then (+ i step)
collect i))
(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 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 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 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))))))
(eval-when (:compile-toplevel :load-toplevel :execute)
(export '(define-constant switch eswitch cswitch while ensure-boolean
with-gensyms with-unique-names once-only iota curry rcurry compose
n-grams)))
;;;; END OF quickutils.lisp ;;;;