## dyn-vector

Dynamic (dense) vectors based on SRFI-43.

## TOC »

## Usage

(require-extension dyn-vector)

## Documentation

The dyn-vector library is an implementation of a dynamically-growing vector, based on SRFI-43. An attempt to set the `i`'th element of a dynvector of underlying size n causes the dynvector to grow to size `2n`, `i+1`, or `16`, whichever is greatest. The semantics of this library follow SRFI-43 closely, with the exception of the following procedures:

`dynvector-ref`procedureIf the index

`i`is greater than the current size of the vector, this procedure returns the default value specified when the dynamic vector was created.

`dynvector-set!`procedureIf the index

`i`is greater than the current size of the vector, the vector size is increased to`max(2*N,i+1)`and the new element is then inserted in the vector.

`dynvector-clear!`procedureThis procedure removes all elements from the dynamic vector, and sets the size of the vector to

`n`.

`dynvector-extend!`procedureThis procedure explicitly resizes the dynamic vector to the specified size.

`dynvector-tabulate`procedureIf the optional argument

`dflt`is specified, it is used as default value, otherwise the first element in the vector is used as default value.

`list->dynvector`procedureIf the optional argument

`dflt`is specified, it is used as default value, otherwise the first element in the list is used as default value.

### Procedures

`dynvector?`procedureReturns

`#t`if`x`is a dynamic vector,`#f`otherwise.

`dynvector-tabulate`procedureCreates a new dynamic vector of length

`len`and iterates across each index, applying f at each iteration to the current index; if the optional argument`dflt`is specified, it is used as default value, otherwise the first element in the vector is used as default value.

`list->dynvector`procedureCreates a dynamic vector with the elements of the given list; if the optional argument

`dflt`is specified, it is used as default value, otherwise the first element in the vector is used as default value.

`dynvector`procedureCreates a dynamic vector with the given elements; the default value is

`#f`.

`make-dynvector`procedureCreates a dynamic vector of length

`n`and fills it with value`default`.

`dynvector-clear!`procedureRemoves all elements from the given dynamic vector, and sets the size of the vector to

`n`.

`dynvector-length`procedureReturns the length of the given dynamic vector.

`dynvector-ref`procedureReturns the element at index

`i`of the given dynamic vector`x`.

`dynvector-set!`procedureUpdates the element at index

`i`of the given dynamic vector`x`; if the index`i`is greater than the current size of the vector, the vector size is increased to`max(2*N,i+1)`and the new element is then inserted in the vector.

`dynvector-expand!`procedureExpands the size of the dynamic vector to the given size

`n`.

`dynvector-for-each`procedureDynamic vector iterator: applies

`f`to each index in the range`[0, k)`, where`k`is the length of the smallest dynamic vector argument passed, and the respective list of parallel elements from`x1`... at that index.

`dynvector-map`procedureConstructs a new dynamic vector of the shortest size of the given dynamic vector; each element at index

`i`of the new dynamic vector is mapped from the old vectors by`f i (dynvector-ref x1 i) ...`.

`dynvector-copy`procedureCreates a copy of the given dynamic vector.

`dynvector-fold`procedureLeft-to-right dynamic vector iterator with state.

`f`is iterated over each index in all of the vectors, stopping at the end of the shortest;`f`is applied as`(f i state (dynvector-ref x1 i) ...)`where state is the current state value, which begins with`initial`and becomes whatever`f`returns at the respective iteration;`i`is the current index.

`dynvector-fold-right`procedureRight-to-left dynamic vector iterator with state.

`f`is iterated over each index in all of the vectors, stopping at the end of the shortest;`f`is applied as`(f i state (dynvector-ref x1 i) ...)`where state is the current state value, which begins with`initial`and becomes whatever`f`returns at the respective iteration;`i`is the current index.

`dynvector-index`procedureFinds and returns the index of the first elements in

`x1 ...`that satisfy`pred?`; if no matching element is found by the end of the shortest vector,`#f`is returned.

`dynvector-any`procedureFinds the first set of elements in

`x1 ...`for which`pred?`returns a true value. If such a parallel set of elements exists, this procedure returns the value that`pred?`returned for that set of elements.

`dynvector-every`procedureIf, for every index

`i`between 0 and the length of the shortest vector argument, the set of elements`(dynvector-ref x1 i) ...`satisfies`pred?`, this procedure returns the value that`pred?`returned for the last set of elements.

`dynvector->list`procedureReturns a list containing all the elements in the given dynamic vector.

## Examples

csi> (require-extension dyn-vector) csi> (define dv (make-dynvector 1 0)) csi> (dynvector-ref dv 6) 0 csi> (dynvector-set! dv 6 18) csi> (dynvector-ref dv 6) 18 csi> (define dv2 (list->dynvector '(1 2 3))) csi> dv2 #(dynvector 1 2 3) csi> (dynvector-ref dv2 4) 1 csi> (dynvector-clear! dv2 5) csi> (dynvector-for-each (lambda (i x) (print i " = " x)) dv2) 0 = 1 1 = 1 2 = 1 3 = 1 4 = 1 csi> (dynvector-map (lambda (i x) (+ x i)) dv2) #(dynvector 1 2 3 4 5) csi> (dynvector-fold (lambda (i state v) (+ state v)) 0 dv2) 5

## About this egg

### Author

### Version history

- 1.13
- Bug fixes for zero-sized vectors; added procedure dynvector [thanks to Lewis Campbell]
- 1.12
- License change to LGPL-3
- 1.11
- Converted documentation to wiki format
- 1.9
- Ported to Chicken 4
- 1.8
- Build script updated for better cross-platform compatibility
- 1.7
- eggdoc documentation fix
- 1.6
- License upgrade to GPL v3
- 1.5
- Minor updates to the setup script
- 1.4
- Bug fix in the setup script
- 1.3
- Added a clarification of how the vector grows [thanks to John Cowan]
- 1.2
- Bug fix to handle zero-length initial base vector
- 1.1
- Added optional dflt argument to list->dynvector and dynvector->tabulate
- 1.0
- Initial release

### License

Parts of this documentation are taken from SRFI-43. The rest was created by Ivan Raikov. This program is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. A full copy of the Lesser GPL license can be found at <http://www.gnu.org/licenses/>.