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# (lispkit gvector)

This library defines an API for

*growable vectors*. Just like regular vectors,*growable vectors*are heterogeneous sequences of elements which are indexed by a range of integers. Unlike for regular vectors, the length of a*growable vector*is not fixed. Growable vectors may expand or shrink in length. Nevertheless, growable vectors are fully compatible to regular vectors and all operations from library`(lispkit vector)`

may also be used in combination with growable vectors. The main significance of library `(lispkit gvector)`

is in providing functions to construct growable vectors. Growable vectors are always *mutable*by design.Just like for vectors with a fixed length, the valid indexes of a growable vector are the exact, non-negative integers less than the length of the vector. The first element in a vector is indexed by zero, and the last element is indexed by one less than the length of the growable vector.

Two growable vectors are

`equal?`

if they have the same length, and if the values in corresponding slots of the vectors are `equal?`

. A growable vector is never `equal?`

a regular vector of fixed length.Growable vectors are written using the notation

`#g(obj ...)`

. For example, a growable vector of initial length 3 containing the number one as element 0, the list (8 16 32) as element 1, and the string "Scheme" as element 2 can be written as follows: `#g(1 (8 16 32) "Scheme")`

.Growable vector constants are self-evaluating, so they do not need to be quoted in programs.

**(gvector?**

*obj***)**

Returns

`#t`

if *obj*is a growable vector; otherwise returns`#f`

.**(gvector-empty?**

*obj***)**

Returns

`#t`

if *obj*is a growable vector of length zero; otherwise returns`#f`

.**(make-gvector)**

**(make-gvector**

*c***)**

Returns a newly allocated growable vector of capacity

*c*. The capacity is used to pre-allocate space for up to*c*elements.**(gvector**

*obj ...***)**

Returns a newly allocated growable vector whose elements contain the given arguments.

(gvector ’a ’b ’c) ⇒ #g(a b c)

**(list->gvector**

*list***)**

The

`list->gvector`

procedure returns a newly created growable vector initialized to the elements of the list *list*in the order of the list.(list->gvector ’(a b c)) ⇒ #g(a b c)

**(vector->gvector**

*vector***)**

Returns a newly allocated growable vector initialized to the elements of the vector

*vector*in the order of*vector*.**(gvector-copy**

*vector***)**

**(gvector-copy**

*vector start***)**

**(gvector-copy**

*vector start end***)**

Returns a newly allocated copy of the elements of the given growable vector between

*start*and*end*, but excluding the element at index*end*. The elements of the new vector are the same (in the sense of`eqv?`

) as the elements of the old.**(gvector-append**

*vector ...***)**

Returns a newly allocated growable vector whose elements are the concatenation of the elements of the given vectors.

(gvector-append #(a b c) #g(d e f)) ⇒ #g(a b c d e f)

**(gvector-concatenate**

*vector xs***)**

Returns a newly allocated growable vector whose elements are the concatenation of the elements of the vectors in

*xs*.*xs*is a proper list of vectors.(gvector-concatenate '(#g(a b c) #(d) #g(e f))) ⇒ #g(a b c d e f)

**(gvector-map**

*f vector1 vector2 ...***)**

Constructs a new growable vector of the shortest size of the vector arguments

*vector1*,*vector2*, etc. Each element at index*i*of the new vector is mapped from the old vectors by`(f (vector-ref vector1 i) (vector-ref vector2 i) ...)`

. The dynamic order of the application of f is unspecified.(gvector-map + #(1 2 3 4 5) #g(10 20 30 40)) ⇒ #g(11 22 33 44)

**(gvector-map/index**

*f vector1 vector2 ...***)**

Constructs a new growable vector of the shortest size of the vector arguments

*vector1*,*vector2*, etc. Each element at index*i*of the new vector is mapped from the old vectors by`(f i (vector-ref vector1 i) (vector-ref vector2 i) ...)`

. The dynamic order of the application of f is unspecified.(gvector-map/index (lambda (i x y) (cons i (+ x y))) #g(1 2 3) #(10 20 30)) ⇒ #g((0 . 11) (1 . 22) (2 . 33))

**(gvector-for-each**

*f vector1 vector2 ...***)**

`gvector-for-each`

implements a simple vector iterator: it applies *f*to the corresponding list of parallel elements from vectors

*vector1 vector2 ...*in the range

*[0, length)*, where

*length*is the length of the smallest vector argument passed. In contrast with

`gvector-map`

, *f*is reliably applied to each subsequent element, starting at index 0, in the vectors.

(gvector-for-each (lambda (x) (display x) (newline))

#g("foo" "bar" "baz" "quux" "zot"))

⇒

foo

bar

baz

quux

zot

**(gvector-for-each/index**

*f vector1 vector2 ...***)**

`gvector-for-each/index`

implements a simple vector iterator: it applies *f*to the index

*i*and the corresponding list of parallel elements from

*vector1 vector2 ...*in the range

*[0, length)*, where

*length*is the length of the smallest vector argument passed. The only difference to

`gvector-for-each`

is that `gvector-for-each/index`

always passes the current index as the first argument of *f*in addition to the elements from the vectors

*vector1 vector2 ...*.

(gvector-for-each/index

(lambda (i x) (display i)(display ": ")(display x)(newline))

#g("foo" "bar" "baz" "quux" "zot"))

⇒

0: foo

1: bar

2: baz

3: quux

4: zot

**(gvector-length**

*vector***)**

Returns the number of elements in growable vector

*vector*as an exact integer.**(gvector-ref**

*vector k***)**

The

`gvector-ref`

procedure returns the contents of element *k*of*vector*. It is an error if*k*is not a valid index of*vector*or if*vector*is not a growable vector.(gvector-ref ’#g(1 1 2 3 5 8 13 21) 5) ⇒ 8

(gvector-ref ’#g(1 1 2 3 5 8 13 21) (exact (round (* 2 (acos -1))))) ⇒ 13

**(gvector-set!**

*vector k obj***)**

The

`vector-set!`

procedure stores *obj*in element*k*of growable vector*vector*. It is an error if*k*is not a valid index of*vector*or if*vector*is not a growable vector.(let ((vec (gvector 0 '(2 2 2 2) "Anna")))

(gvector-set! vec 1 '("Sue" "Sue"))

vec)

⇒ #g(0 ("Sue" "Sue") "Anna")

**(gvector-add!**

*vector obj ...***)**

Appends the values

*obj*, ... to growable vector*vector*. This increases the length of the growable vector by the number of*obj*arguments.(let ((vec (gvector 0 '(2 2 2 2) "Anna")))

(gvector-add! vec "Micha")

vec)

⇒ #g(0 (2 2 2 2) "Anna" "Micha")

**(gvector-insert!**

*vector k obj***)**

Inserts the value

*obj*into growable vector*vector*at index*k*. This increases the length of the growable vector by one.(let ((vec (gvector 0 '(2 2 2 2) "Anna")))

(gvector-insert! vec 1 "Micha")

vec)

⇒ #g(0 "Micha" (2 2 2 2) "Anna")

**(gvector-remove!**

*vector k***)**

Removes the element at index

*k*from growable vector*vector*. This decreases the length of the growable vector by one.(let ((vec (gvector 0 '(2 2 2 2) "Anna")))

(gvector-remove! vec 1)

vec)

⇒ #g(0 "Anna")

**(gvector-remove-last!**

*vector***)**

Removes the last element of the growable vector

*vector*. This decreases the length of the growable vector by one.(let ((vec (gvector 0 '(2 2 2 2) "Anna")))

(gvector-remove-last! vec)

vec)

⇒ #g(0 (2 2 2 2))

Procedures which operate only on a part of a growable vector specify the applicable range in terms of an index interval [

*start*;*end*[; i.e. the*end*index is always exclusive.**(gvector-copy!**

*to at from***)**

**(gvector-copy!**

*to at from start***)**

**(gvector-copy!**

*to at from start end***)**

Copies the elements of vector

*from*between*start*and*end*to growable vector*to*, starting at*at*. The order in which elements are copied is unspecified, except that if the source and destination overlap, copying takes place as if the source is first copied into a temporary vector and then into the destination.*start*defaults to 0 and*end*defaults to the length of*vector*.It is an error if

*at*is less than zero or greater than the length of*to*. It is also an error if`(- (gvector-length to) at)`

is less than `(- end start)`

.(define a (vector 1 2 3 4 5))

(define b (gvector 10 20 30 40 50))

(gvector-copy! b 1 a 0 2)

b ⇒ #g(10 1 2 40 50)

**(gvector-append!**

*vector v1 ...***)**

Appends the elements of the vectors

*v1 ...*to the growable vector*vector*in the given order.**(gvector-reverse!**

*vector***)**

**(gvector-reverse!**

*vector start***)**

**(gvector-reverse!**

*vector start end***)**

Procedure

`gvector-reverse!`

destructively reverses the contents of growable *vector*between*start*and*end*.*start*defaults to 0 and*end*defaults to the length of*vector*.(define a (gvector 1 2 3 4 5))

(vector-reverse! a)

a ⇒ #g(5 4 3 2 1)

**(gvector-sort!**

*pred vector***)**

Procedure

`gvector-sort!`

destructively sorts the elements of growable vector *vector*using the "less than" predicate*pred*.(define a (gvector 7 4 9 1 2 8 5))

(gvector-sort! < a)

a ⇒ #g(1 2 4 5 7 8 9)

**(gvector-map!**

*f vector1 vector2 ...***)**

Similar to

`gvector-map`

which maps the various elements into a new vector via function *f*, procedure`gvector-map!`

destructively inserts the mapped elements into growable vector *vector1*. The dynamic order in which*f*gets applied to the elements is unspecified.(define a (gvector 1 2 3 4))

(gvector-map! + a #(10 20 30))

a ⇒ #g(11 22 33 4)

**(gvector-map/index!**

*f vector1 vector2 ...***)**

Similar to

`gvector-map/index`

which maps the various elements together with their index into a new vector via function *f*, procedure`gvector-map/index!`

destructively inserts the mapped elements into growable vector *vector1*. The dynamic order in which*f*gets applied to the elements is unspecified.(define a #g(1 2 3 4))

(gvector-map/index! (lambda (i x y) (cons i (+ x y))) a #(10 20 30))

a ⇒ #g((0 . 11) (1 . 22) (2 . 33) 4)

**(gvector->list**

*vector***)**

**(gvector->list**

*vector start***)**

**(gvector->list**

*vector start end***)**

The

`gvector->list`

procedure returns a newly allocated list of the objects contained in the elements of growable *vector*between*start*and*end*in the same order as in*vector*.(gvector->list ’#g(dah dah didah)) ⇒ (dah dah didah)

(gvector->list ’#g(dah dah didah) 1 2) ⇒ (dah)

**(gvector->vector**

*vector***)**

**(gvector->vector**

*vector start***)**

**(gvector->vector**

*vector start end***)**

The

`gvector->list`

procedure returns a newly allocated list of the objects contained in the elements of growable vector *vector*between*start*and*end*in the same order as in*vector*.(gvector->list ’#(dah dah didah)) ⇒ error since the argument is not a gvector

(gvector->list ’#g(dah dah didah) 1 2) ⇒ (dah)

Last modified 9mo ago