Utilities | Quickutil

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There are 119 utilities.

factorial v1.0

Compute the factorial of n, where n! = 1 * 2 * ... * n.

Provides: factorial
Requires: range-product

alexandria math

Source Code

binomial-coefficient v1.0

Binomial coefficient of n and k.

Provides: binomial-coefficient
Requires: factorial, range-product

alexandria math

Source Code

define-constant v1.0

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.

Provides: define-constant

alexandria definitions

Source Code

if-let v1.0

Creates new variable bindings, and conditionally executes either then-form or else-form. else-form defaults to nil.

bindings must be either single binding of the form:

(variable initial-form)

or a list of bindings of the form:

((variable-1 initial-form-1)  
 (variable-2 initial-form-2)  
 ...  
 (variable-n initial-form-n))

All initial-forms are executed sequentially in the specified order. Then all the variables are bound to the corresponding values.

If all variables were bound to true values, the then-form is executed with the bindings in effect, otherwise the else-form is executed with the bindings in effect.

Provides: if-let

binding alexandria

Source Code

when-let v1.0

Creates new variable bindings, and conditionally executes a series of forms.

Provides: when-let, when-let*

binding alexandria

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string-designator v1.0

A string designator type. A string designator is either a string, a symbol, or a character.

Provides: string-designator

alexandria types strings

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required-argument v1.0

Signals an error for a missing argument of name. Intended for use as an initialization form for structure and class-slots, and a default value for required keyword arguments.

Provides: required-argument

alexandria conditions

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simple-style-warning v1.0

Provides: simple-style-warning

alexandria conditions

Source Code

simple-reader-error v1.0

Provides: simple-reader-error

alexandria conditions

Source Code

simple-parse-error v1.0

Provides: simple-parse-error

alexandria conditions

Source Code

simple-program-error v1.0

Provides: simple-program-error

alexandria conditions

Source Code

ignore-some-conditions v1.0

Similar to cl:ignore-errors but the (unevaluated) conditions list determines which specific conditions are to be ignored.

Provides: ignore-some-conditions

alexandria conditions

Source Code

unwind-protect-case v1.0

Like cl:unwind-protect, but you can specify the circumstances that the cleanup clauses are run.

clauses ::= (:NORMAL form*)* | (:ABORT form*)* | (:ALWAYS form*)*

Clauses can be given in any order, and more than one clause can be given for each circumstance. The clauses whose denoted circumstance occured, are executed in the order the clauses appear.

abort-flag is the name of a variable that will be bound to t in clauses if the protected-form aborted preemptively, and to nil otherwise.

Examples:

(unwind-protect-case ()  
     (protected-form)  
   (:normal (format t "This is only evaluated if PROTECTED-FORM executed normally.~%"))  
   (:abort  (format t "This is only evaluated if PROTECTED-FORM aborted preemptively.~%"))  
   (:always (format t "This is evaluated in either case.~%")))  
 
(unwind-protect-case (aborted-p)  
     (protected-form)  
   (:always (perform-cleanup-if aborted-p)))

Provides: unwind-protect-case

alexandria conditions

Source Code

copy-hash-table v1.0

Returns a copy of hash table table, with the same keys and values as the table. The copy has the same properties as the original, unless overridden by the keyword arguments.

Before each of the original values is set into the new hash-table, key is invoked on the value. As key defaults to cl:identity, a shallow copy is returned by default.

Provides: copy-hash-table

alexandria hash-tables orthogonality

Source Code

maphash-keys v1.0

Like maphash, but calls function with each key in the hash table table.

Provides: maphash-keys

alexandria hash-tables

Source Code

maphash-values v1.0

Like maphash, but calls function with each value in the hash table table.

Provides: maphash-values

alexandria hash-tables

Source Code

hash-table-keys v1.0

Returns a list containing the keys of hash table table.

Provides: hash-table-keys
Requires: maphash-keys

alexandria hash-tables

Source Code

hash-table-values v1.0

Returns a list containing the values of hash table table.

Provides: hash-table-values
Requires: maphash-values

alexandria hash-tables

Source Code

hash-table-alist v1.0

Returns an association list containing the keys and values of hash table table.

Provides: hash-table-alist

alexandria hash-tables

Source Code

hash-table-plist v1.0

Returns a property list containing the keys and values of hash table table.

Provides: hash-table-plist

alexandria hash-tables

Source Code

alist-hash-table v1.0

Returns a hash table containing the keys and values of the association list alist. Hash table is initialized using the hash-table-initargs.

Provides: alist-hash-table

alexandria hash-tables

Source Code

plist-hash-table v1.0

Returns a hash table containing the keys and values of the property list plist. Hash table is initialized using the hash-table-initargs.

Provides: plist-hash-table

alexandria hash-tables

Source Code

ensure-gethash v1.0

Like gethash, but if key is not found in the hash-table saves the default under key before returning it. Secondary return value is true if key was already in the table.

Provides: ensure-gethash

alexandria hash-tables

Source Code

ensure-symbol v1.0

Returns a symbol with name designated by name, accessible in package designated by package. If symbol is not already accessible in package, it is interned there. Returns a secondary value reflecting the status of the symbol in the package, which matches the secondary return value of intern.

Example:

(ensure-symbol :cons :cl) => cl:cons, :external

Provides: ensure-symbol

alexandria symbols

Source Code

format-symbol v1.0

Constructs a string by applying arguments to string designator control as if by format within with-standard-io-syntax, and then creates a symbol named by that string.

If package is nil, returns an uninterned symbol, if package is t, returns a symbol interned in the current package, and otherwise returns a symbol interned in the package designated by package.

Provides: format-symbol

alexandria symbols

Source Code

make-keyword v1.0

Interns the string designated by name in the keyword package.

Provides: make-keyword

alexandria symbols

Source Code

make-gensym v1.0

If name is a non-negative integer, calls gensym using it. Otherwise name must be a string designator, in which case calls gensym using the designated string as the argument.

Provides: make-gensym

alexandria symbols

Source Code

make-gensym-list v1.0

Returns a list of length gensyms, each generated as if with a call to make-gensym, using the second (optional, defaulting to "G") argument.

Provides: make-gensym-list

alexandria symbols

Source Code

symbolicate v1.0

Concatenate together the names of some strings and symbols, producing a symbol in the current package.

Provides: symbolicate

alexandria symbols

Source Code

with-gensyms v1.0

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.

Provides: with-gensyms, with-unique-names
Requires: string-designator

alexandria macro-writing

Source Code

once-only v1.0

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)

Provides: once-only
Requires: make-gensym-list

alexandria macro-writing

Source Code

parse-body v1.0

Parses body into (values remaining-forms declarations doc-string). Documentation strings are recognized only if documentation is true. Syntax errors in body are signalled and whole is used in the signal arguments when given.

Provides: parse-body

alexandria macro-writing

Source Code

parse-ordinary-lambda-list v1.0

Parses an ordinary lambda-list, returning as multiple values:

Required parameters.
Optional parameter specifications, normalized into form:

(name init suppliedp)

Name of the rest parameter, or nil.
Keyword parameter specifications, normalized into form:

((keyword-name name) init suppliedp)

Boolean indicating &allow-other-keys presence.
&aux parameter specifications, normalized into form

(name init).

Existence of &key in the lambda-list.

Signals a program-error if lambda-list is malformed.

Provides: parse-ordinary-lambda-list
Requires: simple-program-error, ensure-list, make-keyword

alexandria macro-writing

Source Code

destructuring-case v1.0

destructuring-case, 'destructuring-ccase and 'destructuring-ecase are a combination of case and destructuring-bind. keyform must evaluate to af cons.

Clauses are of the form:

((case-keys . destructuring-lambda-list) form*)

The clause whose case-keys matches car of key, as if by case, ccase, or ecase, is selected, and forms are then executed with cdr of key is destructured and Bound By The destructuring-lambda-list.

Example:

(defun dcase (x)  
  (destructuring-case x  
    ((:foo a b)  
     (format nil "foo: ~S, ~S" a b))  
    ((:bar &key a b)  
     (format nil "bar, ~S, ~S" a b))  
    (((:alt1 :alt2) a)  
     (format nil "alt: ~S" a))  
    ((t &rest rest)  
     (format nil "unknown: ~S" rest))))  
 
 (dcase (list :foo 1 2))        ; => "foo: 1, 2"  
 (dcase (list :bar :a 1 :b 2))  ; => "bar: 1, 2"  
 (dcase (list :alt1 1))         ; => "alt: 1"  
 (dcase (list :alt2 2))         ; => "alt: 2"  
 (dcase (list :quux 1 2 3))     ; => "unknown: 1, 2, 3"  
 
(defun decase (x)  
  (destructuring-case x  
    ((:foo a b)  
     (format nil "foo: ~S, ~S" a b))  
    ((:bar &key a b)  
     (format nil "bar, ~S, ~S" a b))  
    (((:alt1 :alt2) a)  
     (format nil "alt: ~S" a))))  
 
 (decase (list :foo 1 2))        ; => "foo: 1, 2"  
 (decase (list :bar :a 1 :b 2))  ; => "bar: 1, 2"  
 (decase (list :alt1 1))         ; => "alt: 1"  
 (decase (list :alt2 2))         ; => "alt: 2"  
 (decase (list :quux 1 2 3))     ; =| error

Provides: destructuring-case, destructuring-ccase, destructuring-ecase
Requires: once-only

alexandria macro-writing

Source Code

extract-function-name v1.0

Useful for macros that want to mimic the functional interface for functions like #'eq and 'eq.

Provides: extract-function-name

alexandria control

Source Code

switch v1.0

Dispatch to different branches of code based off of the value of an expression.

Provides: switch, eswitch, cswitch
Requires: with-gensyms, extract-function-name

alexandria control

Source Code

whichever v1.0

Evaluates exactly one of possibilities, chosen at random.

Provides: whichever
Requires: with-gensyms

alexandria control

Source Code

xor v1.0

Evaluates its arguments one at a time, from left to right. If more then one argument evaluates to a true value no further datums are evaluated, and nil is returned as both primary and secondary value. If exactly one argument evaluates to true, its value is returned as the primary value after all the arguments have been evaluated, and t is returned as the secondary value. If no arguments evaluate to true nil is retuned as primary, and t as secondary value.

Provides: xor
Requires: with-gensyms

alexandria control orthogonality

Source Code

nth-value-or v1.0

Evaluates form arguments one at a time, until the nth-value returned by one of the forms is true. It then returns all the values returned by evaluating that form. If none of the forms return a true nth value, this form returns nil.

Provides: nth-value-or
Requires: with-gensyms, once-only

alexandria control

Source Code

multiple-value-prog2 v1.0

Evaluates first-form, then second-form, and then forms. Yields as its value all the value returned by second-form.

Provides: multiple-value-prog2

alexandria control orthogonality

Source Code

featurep v1.0

Returns t if the argument matches the state of the *features* list and nil if it does not. feature-expression can be any atom or list acceptable to the reader macros #+ and #-.

Provides: featurep
Requires: switch

alexandria features

Source Code

ensure-function v1.0

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.

Provides: ensure-function

alexandria functional

Source Code

ensure-functionf v1.0

Multiple-place modify macro for ensure-function: ensures that each of places contains a function.

Provides: ensure-functionf
Requires: ensure-function

alexandria functional

Source Code

disjoin v1.0

Returns a function that applies each of predicate and more-predicate functions in turn to its arguments, returning the primary value of the first predicate that returns true, without calling the remaining predicates. If none of the predicates returns true, nil is returned.

Provides: disjoin
Requires: ensure-function

alexandria functional orthogonality

Source Code

conjoin v1.0

Returns a function that applies each of predicate and more-predicate functions in turn to its arguments, returning nil if any of the predicates returns false, without calling the remaining predicates. If none of the predicates returns false, returns the primary value of the last predicate.

Provides: conjoin

alexandria functional orthogonality

Source Code

compose v1.0

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.

Provides: compose
Requires: make-gensym-list, ensure-function

alexandria functional orthogonality

Source Code

multiple-value-compose v1.0

Returns a function composed of function and more-functions that applies its arguments to each in turn, starting from the rightmost of more-functions, and then calling the next one with all the return values of the last.

Provides: multiple-value-compose
Requires: make-gensym-list, ensure-function

alexandria functional orthogonality

Source Code

curry v1.0

Returns a function that applies arguments and the arguments it is called with to function.

Provides: curry
Requires: make-gensym-list, ensure-function

alexandria functional

Source Code

rcurry v1.0

Returns a function that applies the arguments it is called with and arguments to function.

Provides: rcurry
Requires: ensure-function

alexandria functional

Source Code

named-lambda v1.0

Expands into a lambda-expression within whose body name denotes the corresponding function.

Provides: named-lambda

alexandria functional

Source Code

array-bounds v1.0

Types related to array bounds.

Provides: array-index, array-length

alexandria types arrays cdr

Source Code

sub-interval-numeric-types v1.0

Contains 'sub-interval numeric types'. Majority of the implementation of CDR5.

Provides: negative-double-float, negative-fixnum-p, negative-float, negative-float-p, negative-long-float, negative-long-float-p, negative-rational, negative-rational-p, negative-real, negative-single-float-p, non-negative-double-float, non-negative-double-float-p, non-negative-fixnum, non-negative-fixnum-p, non-negative-float, non-negative-float-p, non-negative-integer-p, non-negative-long-float, non-negative-rational, non-negative-real-p, non-negative-short-float-p, non-negative-single-float, non-negative-single-float-p, non-positive-double-float, non-positive-double-float-p, non-positive-fixnum, non-positive-fixnum-p, non-positive-float, non-positive-float-p, non-positive-integer, non-positive-rational, non-positive-real, non-positive-real-p, non-positive-short-float, non-positive-short-float-p, non-positive-single-float-p, positive-double-float, positive-double-float-p, positive-fixnum, positive-fixnum-p, positive-float, positive-float-p, positive-integer, positive-rational, positive-real, positive-real-p, positive-short-float, positive-short-float-p, positive-single-float, positive-single-float-p, negative-double-float-p, negative-fixnum, negative-integer, negative-integer-p, negative-real-p, negative-short-float, negative-short-float-p, negative-single-float, non-negative-integer, non-negative-long-float-p, non-negative-rational-p, non-negative-real, non-negative-short-float, non-positive-integer-p, non-positive-long-float, non-positive-long-float-p, non-positive-rational-p, non-positive-single-float, positive-integer-p, positive-long-float, positive-long-float-p, positive-rational-p
Requires: format-symbol

alexandria types cdr

Source Code

of-type v1.0

Returns a function of one argument, which returns true when its argument is of TYPE.

Provides: of-type
Requires: with-gensyms

alexandria

Source Code

type= v1.0

Returns a primary value of t is type1 and type2 are the same type, and a secondary value that is true is the type equality could be reliably determined: primary value of nil and secondary value of t indicates that the types are not equivalent.

Provides: type=

alexandria types

Source Code

coercef v1.0

Modify-macro for coerce.

Provides: coercef

alexandria types

Source Code

copy-array v1.0

Returns an undisplaced copy of array, with same fill-pointer and adjustability (if any) as the original, unless overridden by the keyword arguments.

Provides: copy-array

alexandria arrays orthogonality

Source Code

alist-plist v1.0

Convert between alists and plists.

Provides: alist-plist, plist-alist
Requires: safe-endp

alexandria lists alists plists

Source Code

assoc-value v1.0

Getters and setters for assoc and rassoc values.

Provides: assoc-value, rassoc-value
Requires: with-gensyms

alexandria lists alists

Source Code

doplist v1.0

Iterates over elements of plist. body can be preceded by declarations, and is like a tagbody. return may be used to terminate the iteration early. If return is not used, returns values.

Provides: doplist
Requires: parse-body, with-gensyms

alexandria lists plists

Source Code

appendf v1.0

Modify-macro for append. Appends lists to the place designated by the first argument.

Provides: appendf

alexandria lists

Source Code

nconcf v1.0

Modify-macro for nconc. Concatenates lists to place designated by the first argument.

Provides: nconcf

alexandria lists

Source Code

unionf v1.0

Modify-macro for union. Saves the union of list and the contents of the place designated by the first argument to the designated place.

Provides: unionf

alexandria lists sets

Source Code

nunionf v1.0

Modify-macro for nunion. Saves the union of list and the contents of the place designated by the first argument to the designated place. May modify either argument.

Provides: nunionf

alexandria lists sets

Source Code

reversef v1.0

Modify-macro for reverse. Copies and reverses the list stored in the given place and saves back the result into the place.

Provides: reversef

alexandria lists

Source Code

nreversef v1.0

Modify-macro for nreverse. Reverses the list stored in the given place by destructively modifying it and saves back the result into the place.

Provides: nreversef

alexandria lists

Source Code

circular-list v1.0

Creation and detection of circular lists.

Provides: circular-list, circular-list-p, make-circular-list

alexandria lists types

Source Code

circular-tree-p v1.0

Returns true if object is a circular tree, nil otherwise.

Provides: circular-tree-p

alexandria trees

Source Code

proper-list-p v1.0

Returns true if object is a proper list.

Provides: proper-list-p

alexandria lists orthogonality

Source Code

proper-list v1.0

Type designator for proper lists. Implemented as a satisfies type, hence not recommended for performance intensive use. Main usefulness as a type designator of the expected type in a type-error.

Provides: proper-list
Requires: proper-list-p

alexandria types lists orthogonality

Source Code

proper-list-length/last-car v1.0

Compute the length of a proper list, and the last CAR of a list quickly.

Provides: proper-list-length, last-car
Requires: circular-list, safe-endp

alexandria lists

Source Code

ensure-car v1.0

If thing is a cons, its car is returned. Otherwise thing is returned.

Provides: ensure-car

alexandria lists conses

Source Code

ensure-cons v1.0

If cons is a cons, it is returned. Otherwise returns a fresh cons with cons in the car, and nil in the cdr.

Provides: ensure-cons

alexandria lists conses

Source Code

ensure-list v1.0

If list is a list, it is returned. Otherwise returns the list designated by list.

Provides: ensure-list

alexandria lists

Source Code

remove-from-plist v1.0

Destructive and non-destructive functions to remove items from a plist, as well as associated modify macros.

Provides: remove-from-plist, delete-from-plist, remove-from-plistf, delete-from-plistf, sans

alexandria lists

Source Code

mappend v1.0

Applies function to respective element(s) of each list, appending all the all the result list to a single list. function must return a list.

Provides: mappend

alexandria lists orthogonality

Source Code

setp v1.0

Returns true if object is a list that denotes a set, nil otherwise. A list denotes a set if each element of the list is unique under key and test.

Provides: setp

alexandria lists sets

Source Code

set-equal v1.0

Returns true if every element of list1 matches some element of list2 and every element of list2 matches some element of list1. Otherwise returns false.

Provides: set-equal

alexandria lists sets

Source Code

map-product v1.0

Returns a list containing the results of calling function with one argument from list, and one from each of more-lists for each combination of arguments. In other words, returns the product of list and more-lists using function.

Example:

(map-product 'list '(1 2) '(3 4) '(5 6))  
 => ((1 3 5) (1 3 6) (1 4 5) (1 4 6)  
     (2 3 5) (2 3 6) (2 4 5) (2 4 6))

Provides: map-product
Requires: ensure-function, curry, mappend

alexandria lists

Source Code

with-open-file* v1.0

Just like with-open-file, but nil values in the keyword arguments mean to use the default value specified for open.

Provides: with-open-file*
Requires: once-only

alexandria files io

Source Code

with-input-from-file v1.0

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.

Provides: with-input-from-file
Requires: with-open-file*

alexandria files io

Source Code

with-output-to-file v1.0

Evaluate body with stream-name to an output 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.

Provides: with-output-to-file
Requires: with-open-file*

alexandria files io

Source Code

read-file-into-string v1.0

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.

Provides: read-file-into-string
Requires: with-input-from-file

alexandria files io strings

Source Code

write-string-into-file v1.0

Write string to pathname.

The external-format parameter will be passed directly to with-open-file unless it's nil, which means the system default.

Provides: write-string-into-file
Requires: with-output-to-file

alexandria files io strings

Source Code

read-file-into-byte-vector v1.0

Read pathname into a freshly allocated (unsigned-byte 8) vector.

Provides: read-file-into-byte-vector
Requires: with-input-from-file

alexandria files io

Source Code

write-byte-vector-into-file v1.0

Write bytes to pathname.

Provides: write-byte-vector-into-file
Requires: with-output-to-file

alexandria files io

Source Code

copy-file v1.0

Copy a file from from to to.

Provides: copy-file
Requires: copy-stream, with-output-to-file, with-input-from-file

alexandria files io orthogonality

Source Code

copy-stream v1.0

Reads data from input and writes it to output. Both input and output must be streams, they will be passed to read-sequence and write-sequence and must have compatible element-types.

Provides: copy-stream
Requires: sub-interval-numeric-types

alexandria files io orthogonality

Source Code

sequence-of-length-p v1.0

Provides: sequence-of-length-p
Requires: array-bounds

alexandria sequences

Source Code

rotate v1.0

Returns a sequence of the same type as sequence, with the elements of sequence rotated by n: n elements are moved from the end of the sequence to the front if n is positive, and -n elements moved from the front to the end if n is negative. sequence must be a proper sequence. n must be an integer, defaulting to 1.

If absolute value of n is greater then the length of the sequence, the results are identical to calling rotate with

(* (signum n) (mod n (length sequence))).

Note: the original sequence may be destructively altered, and result sequence may share structure with it.

Provides: rotate
Requires: proper-list-length/last-car

alexandria sequences

Source Code

shuffle v1.0

Returns a random permutation of sequence bounded by start and end. Original sequece may be destructively modified, and share storage with the original one. Signals an error if sequence is not a proper sequence.

Provides: shuffle
Requires: proper-list-length/last-car

alexandria random sequences

Source Code

random-elt v1.0

Returns a random element from sequence bounded by start and end. Signals an error if the sequence is not a proper non-empty sequence, or if end and start are not proper bounding index designators for sequence.

Provides: random-elt
Requires: proper-list-length/last-car

alexandria random sequences

Source Code

removef v1.0

Modify-macro for remove. Sets place designated by the first argument to the result of calling remove with item, place, and the keyword-arguments.

Provides: removef

alexandria sequences

Source Code

deletef v1.0

Modify-macro for delete. Sets place designated by the first argument to the result of calling delete with item, place, and the keyword-arguments.

Provides: deletef

alexandria sequences

Source Code

proper-sequence v1.0

Type designator for proper sequences, that is proper lists and sequences that are not lists.

Provides: proper-sequence
Requires: proper-list

alexandria sequences types

Source Code

length= v1.0

Takes any number of sequences or integers in any order. Returns true iff the length of all the sequences and the integers are equal.

Hint: there's a compiler macro that expands into more efficient code if the first argument is a literal integer.

Provides: length=
Requires: with-gensyms, sequence-of-length-p, array-bounds

alexandria sequences

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copy-sequence v1.0

Returns a fresh sequence of type, which has the same elements as sequence.

Provides: copy-sequence

alexandria sequences

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first-elt v1.0

Getter and setter for the first element of a sequence.

Provides: first-elt
Requires: emptyp

alexandria sequences setters

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last-elt v1.0

Getter and setter for the last element of a sequence.

Provides: last-elt
Requires: proper-list-length/last-car, emptyp, proper-sequence

alexandria sequences

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starts-with-subseq v1.0

Test whether the first elements of SEQUENCE are the same (as per TEST) as the elements of PREFIX.

If RETURN-SUFFIX is T the functions returns, as a second value, a displaced array pointing to the sequence after PREFIX.

Provides: starts-with-subseq
Requires: remove-from-plist

alexandria sequences

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ends-with-subseq v1.0

Test whether sequence ends with suffix. In other words: return true if the last (length suffix) elements of sequence are equal to suffix.

Provides: ends-with-subseq

alexandria sequences

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starts-with v1.0

Returns true if sequence is a sequence whose first element is eql to object. Returns nil if the sequence is not a sequence or is an empty sequence.

Provides: starts-with

alexandria sequences

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ends-with v1.0

Returns true if sequence is a sequence whose last element is eql to object. Returns nil if the sequence is not a sequence or is an empty sequence. Signals an error if sequence is an improper list.

Provides: ends-with
Requires: proper-list-length/last-car

alexandria sequences

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map-combinations v1.0

Calls function with each combination of length constructable from the elements of the subsequence of sequence delimited by start and end. start defaults to 0, end to length of sequence, and length to the length of the delimited subsequence. (So unless length is specified there is only a single combination, which has the same elements as the delimited subsequence.) If copy is true (the default) each combination is freshly allocated. If copy is false all combinations are eq to each other, in which case consequences are specified if a combination is modified by function.

Provides: map-combinations
Requires: ensure-function

alexandria sequences math

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map-permutations v1.0

Calls function with each permutation of length constructable from the subsequence of sequence delimited by start and end. start defaults to 0, end to length of the sequence, and length to the length of the delimited subsequence.

Provides: map-permutations
Requires: map-combinations

alexandria sequences math

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map-derangements v1.0

Calls function with each derangement of the subsequence of sequence denoted by the bounding index designators start and end. Derangement is a permutation of the sequence where no element remains in place. sequence is not modified, but individual derangements are eq to each other. Consequences are unspecified if calling function modifies either the derangement or sequence.

Provides: map-derangements

alexandria sequences math

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extremum v1.0

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.

Provides: extremum
Requires: ensure-function

alexandria sequences math

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clamp v1.0

Clamps the number into [min, max] range. Returns min if number is lesser then min and max if number is greater then max, otherwise returns number.

Provides: clamp

alexandria math

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gaussian-random v1.0

Returns two gaussian random double floats as the primary and secondary value, optionally constrained by min and max. Gaussian random numbers form a standard normal distribution around 0.0d0.

Sufficiently positive min or negative max will cause the algorithm used to take a very long time. If min is positive it should be close to zero, and similarly if max is negative it should be close to zero.

Provides: gaussian-random

alexandria math random

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iota v1.0

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)

Provides: iota

alexandria lists

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map-iota v1.0

Calls function with 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. Returns n.

Examples:

(map-iota #'print 3 :start 1 :step 1.0) => 3  
  ;;; 1.0  
  ;;; 2.0  
  ;;; 3.0

Provides: map-iota

alexandria

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lerp v1.0

Returns the result of linear interpolation between a and b, using the interpolation coefficient v.

Provides: lerp

alexandria math

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mean v1.0

Returns the mean of sample. sample must be a sequence of numbers.

Provides: mean

alexandria math statistics

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median v1.0

Returns median of sample. sample must be a sequence of real numbers.

Provides: median
Requires: copy-sequence

alexandria math statistics

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variance v1.0

Variance of sample. Returns the biased variance if biased is true (the default), and the unbiased estimator of variance if biased is false. sample must be a sequence of numbers.

Provides: variance
Requires: mean

alexandria math statistics

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standard-deviation v1.0

Standard deviation of sample. Returns the biased standard deviation if biased is true (the default), and the square root of the unbiased estimator for variance if biased is false (which is not the same as the unbiased estimator for standard deviation). sample must be a sequence of numbers.

Provides: standard-deviation
Requires: variance

alexandria math statistics

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maxf v1.0

Modify-macro for max. Sets place designated by the first argument to the maximum of its original value and numbers.