## 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?``obj`procedureReturns

`#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``obj`procedureReturns the number of dimensions of

`obj`. If`obj`is not an array, 0 is returned.

`array-dimensions``obj`procedureReturns a list of dimensions.

(array-dimensions (make-array '#() 3 5)) => (3 5)

`make-array``prototype``k1``...`procedureCreates 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``list`procedure`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``array`procedureReturns 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``array`procedureReturns 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``...`procedureReturns

`#t`if its arguments would be acceptable to`array-ref`.

`array-ref``array``k1``...`procedureReturns the

`(k1, ...)`element of array.

`array-set!``array``obj``k1``...`procedureStores

`obj`in the`(k1, ...)`element of`array`. The value returned by`array-set!`is unspecified.

`A:floC128b`procedure`A:floC128b``z`procedureReturns an inexact 128-bit flonum complex uniform-array prototype.

`A:floC64b`procedure`A:floC64b``z`procedureReturns an inexact 64-bit flonum complex uniform-array prototype.

`A:floC32b`procedure`A:floC32b``z`procedureReturns an inexact 32-bit flonum complex uniform-array prototype.

`A:floC16b`procedure`A:floC16b``z`procedureReturns an inexact 16-bit flonum complex uniform-array prototype.

`A:floR128b`procedure`A:floR128b``x`procedureReturns an inexact 128-bit flonum real uniform-array prototype.

`A:floR64b`procedure`A:floR64b``x`procedureReturns an inexact 64-bit flonum real uniform-array prototype.

`A:floR32b`procedure`A:floR32b``x`procedureReturns an inexact 32-bit flonum real uniform-array prototype.

`A:floR16b`procedure`A:floR16b``x`procedureReturns an inexact 16-bit flonum real uniform-array prototype.

`A:fixZ64b`procedure`A:fixZ64b``n`procedureReturns an exact binary fixnum uniform-array prototype with at least 64 bits of precision.

`A:fixZ32b`procedure`A:fixZ32b``n`procedureReturns an exact binary fixnum uniform-array prototype with at least 32 bits of precision.

`A:fixZ16b`procedure`A:fixZ16b``n`procedureReturns an exact binary fixnum uniform-array prototype with at least 16 bits of precision.

`A:fixZ8b`procedure`A:fixZ8b``n`procedureReturns an exact binary fixnum uniform-array prototype with at least 8 bits of precision.

`A:fixN64b`procedure`A:fixN64b``k`procedureReturns an exact non-negative binary fixnum uniform-array prototype with at least 64 bits of precision.

`A:fixN32b`procedure`A:fixN32b``k`procedureReturns an exact non-negative binary fixnum uniform-array prototype with at least 32 bits of precision.

`A:fixN16b`procedure`A:fixN16b``k`procedureReturns an exact non-negative binary fixnum uniform-array prototype with at least 16 bits of precision.

`A:fixN8b`procedure`A:fixN8b``k`procedureReturns an exact non-negative binary fixnum uniform-array prototype with at least 8 bits of precision.

`A:bool`procedure`A:bool``boolean`procedureReturns a boolean uniform-array prototype.

## Author

Aubrey Jaffer

## Repository

This egg is hosted on the CHICKEN Subversion repository:

https://anonymous@code.call-cc.org/svn/chicken-eggs/release/5/srfi-63

If you want to check out the source code repository of this egg and you are not familiar with Subversion, see this page.

## 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.

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