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SRFI-63
Homogeneous and Heterogeneous Arrays
TOC »
Documentation
This SRFI, which is to supersede SRFI-47, "Array",
- synthesizes array concepts from Common-Lisp and Alan Bawden's array.scm;
- incorporates all the uniform vector types from SFRI-4 "Homogeneous numeric vector datatypes";
- adds a boolean uniform array type;
- adds 16 bit and 128 bit floating-point uniform-array types;
- adds decimal floating-point uniform-array types; and
- adds array types of (dual) floating-point complex numbers.
For the complete SRFI-63 document see SRFI 63.
Note: this extension is compiled in case-sensitive mode, so array prototype identifiers like A:fixZ64b must be spelled using the correct case.
Homogeneous Array Types
All implementations must support Scheme strings as rank 1 character arrays. This requirement mandates that Scheme strings be valid arguments to array procedures; their stored representations may be different from other character arrays.
Although an implementation is required to define all the prototype functions, it is not required to support all or even any of the homogeneous numeric arrays. It is assumed that no uniform numeric types have larger precision than the Scheme implementation supports as numbers.
prototype procedure | exactness | element type |
---|---|---|
vector | any | |
A:floC128b | inexact | 128 bit binary flonum complex |
A:floC64b | inexact | 64 bit binary flonum complex |
A:floC32b | inexact | 32 bit binary flonum complex |
A:floC16b | inexact | 16 bit binary flonum complex |
A:floR128b | inexact | 128 bit binary flonum real |
A:floR64b | inexact | 64 bit binary flonum real |
A:floR32b | inexact | 32 bit binary flonum real |
A:floR16b | inexact | 16 bit binary flonum real |
A:floQ128d | exact | 128 bit decimal flonum rational |
A:floQ64d | exact | 64 bit decimal flonum rational |
A:floQ32d | exact | 32 bit decimal flonum rational |
A:fixZ64b | exact | 64 bit binary fixnum |
A:fixZ32b | exact | 32 bit binary fixnum |
A:fixZ16b | exact | 16 bit binary fixnum |
A:fixZ8b | exact | 8 bit binary fixnum |
A:fixN64b | exact | 64 bit nonnegative binary fixnum |
A:fixN32b | exact | 32 bit nonnegative binary fixnum |
A:fixN16b | exact | 16 bit nonnegative binary fixnum |
A:fixN8b | exact | 8 bit nonnegative binary fixnum |
A:bool | boolean | |
string | char |
Procedures
- array? objprocedure
Returns #t if the obj is an array, and #f if not.
Note: Arrays are not disjoint from other Scheme types. Vectors and strings also satisfy array?. A disjoint array predicate can be written as follows:
(define (strict-array? obj) (and (array? obj) (not (string? obj)) (not (vector? obj))))
- array-rank objprocedure
Returns the number of dimensions of obj. If obj is not an array, 0 is returned.
- array-dimensions objprocedure
Returns a list of dimensions.
(array-dimensions (make-array '#() 3 5)) => (3 5)
- make-array prototype k1 ...procedure
Creates and returns an array of type prototype with dimensions k1, ... and filled with elements from prototype. prototype must be an array, vector, or string. The implementation-dependent type of the returned array will be the same as the type of prototype; except if that would be a vector or string with rank not equal to one, in which case some variety of array will be returned.
If prototype has no elements, then the initial contents of the returned array are unspecified. Otherwise, the returned array will be filled with the element at the origin of prototype.
make-shared-array can be used to create shared subarrays of other arrays. The mapper is a function that translates coordinates in the new array into coordinates in the old array. A mapper must be linear, and its range must stay within the bounds of the old array, but it can be otherwise arbitrary. A simple example:
(define fred (make-array '#(#f) 8 8)) (define freds-diagonal (make-shared-array fred (lambda (i) (list i i)) 8)) (array-set! freds-diagonal 'foo 3) (array-ref fred 3 3) => FOO (define freds-center (make-shared-array fred (lambda (i j) (list (+ 3 i) (+ 3 j))) 2 2)) (array-ref freds-center 0 0) => FOO
- list->array rank proto listprocedure
list must be a rank-nested list consisting of all the elements, in row-major order, of the array to be created.
list->array returns an array of rank rank and type proto consisting of all the elements, in row-major order, of list. When rank is 0, list is the lone array element; not necessarily a list.
(list->array 2 '#() '((1 2) (3 4))) => #2A((1 2) (3 4)) (list->array 0 '#() 3) => #0A 3
- array->list arrayprocedure
Returns a rank-nested list consisting of all the elements, in row-major order, of array. In the case of a rank-0 array, array->list returns the single element.
(array->list #2A((ho ho ho) (ho oh oh))) => ((ho ho ho) (ho oh oh)) (array->list #0A ho) => ho
- vector->array vect proto dim1 ...procedure
vect must be a vector of length equal to the product of exact nonnegative integers dim1, ....
vector->array returns an array of type proto consisting of all the elements, in row-major order, of vect. In the case of a rank-0 array, vect has a single element.
(vector->array #(1 2 3 4) #() 2 2) => #2A((1 2) (3 4)) (vector->array '#(3) '#()) => #0A 3
- array->vector arrayprocedure
Returns a new vector consisting of all the elements of array in row-major order.
(array->vector #2A ((1 2)( 3 4))) => #(1 2 3 4) (array->vector #0A ho) => #(ho)
- array-in-bounds? array index1 ...procedure
Returns #t if its arguments would be acceptable to array-ref.
- array-ref array k1 ...procedure
Returns the (k1, ...) element of array.
- array-set! array obj k1 ...procedure
Stores obj in the (k1, ...) element of array. The value returned by array-set! is unspecified.
- A:floC128bprocedure
- A:floC128b zprocedure
Returns an inexact 128-bit flonum complex uniform-array prototype.
- A:floC64bprocedure
- A:floC64b zprocedure
Returns an inexact 64-bit flonum complex uniform-array prototype.
- A:floC32bprocedure
- A:floC32b zprocedure
Returns an inexact 32-bit flonum complex uniform-array prototype.
- A:floC16bprocedure
- A:floC16b zprocedure
Returns an inexact 16-bit flonum complex uniform-array prototype.
- A:floR128bprocedure
- A:floR128b xprocedure
Returns an inexact 128-bit flonum real uniform-array prototype.
- A:floR64bprocedure
- A:floR64b xprocedure
Returns an inexact 64-bit flonum real uniform-array prototype.
- A:floR32bprocedure
- A:floR32b xprocedure
Returns an inexact 32-bit flonum real uniform-array prototype.
- A:floR16bprocedure
- A:floR16b xprocedure
Returns an inexact 16-bit flonum real uniform-array prototype.
- A:fixZ64bprocedure
- A:fixZ64b nprocedure
Returns an exact binary fixnum uniform-array prototype with at least 64 bits of precision.
- A:fixZ32bprocedure
- A:fixZ32b nprocedure
Returns an exact binary fixnum uniform-array prototype with at least 32 bits of precision.
- A:fixZ16bprocedure
- A:fixZ16b nprocedure
Returns an exact binary fixnum uniform-array prototype with at least 16 bits of precision.
- A:fixZ8bprocedure
- A:fixZ8b nprocedure
Returns an exact binary fixnum uniform-array prototype with at least 8 bits of precision.
- A:fixN64bprocedure
- A:fixN64b kprocedure
Returns an exact non-negative binary fixnum uniform-array prototype with at least 64 bits of precision.
- A:fixN32bprocedure
- A:fixN32b kprocedure
Returns an exact non-negative binary fixnum uniform-array prototype with at least 32 bits of precision.
- A:fixN16bprocedure
- A:fixN16b kprocedure
Returns an exact non-negative binary fixnum uniform-array prototype with at least 16 bits of precision.
- A:fixN8bprocedure
- A:fixN8b kprocedure
Returns an exact non-negative binary fixnum uniform-array prototype with at least 8 bits of precision.
- A:boolprocedure
- A:bool booleanprocedure
Returns a boolean uniform-array prototype.
Author
Aubrey Jaffer
Version history
License
Copyright (C) 2005 Aubrey Jaffer
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.