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Source for wiki BitwiseCowan version 2

author

cowan

comment

ipnr

66.108.19.185

name

BitwiseCowan

readonly

0

text

= Bitwise arithmetic procedures =

This proposal is based mainly on [http://srfi.schemers.org/srfi-33/srfi-33.html SRFI 33], with some changes and additions from [http://srfi.schemers.org/srfi-33/mail-archive/msg00023.html Olin's late revisions to SRFI 33], which were never consummated, and from [http://srfi.schemers.org/srfi-60/srfi-60.html SRFI 60].  Until a full spec is written, see the final column of the table in BitwiseComparison.

== Reasons for name changes ==

BitwiseCowan retains SRFI 33 names for procedures adopted from SRFI 33, with these exceptions:

* The name `bitwise-merge` is replaced by `bitwise-if`, the name used in SRFI 60 and R6RS.

* The name `extract-bit-field` (`bit-field-extract` in Olin's revisions) is replaced by `bit-field`, the name used in SRFI 60 and R6RS.

* The names `any-bits-set?` and `all-bits-set?` are replaced by `any-bit-set?` and `every-bit-set?`, in accordance with Olin's revisions.

* Because  `copy-bit-field` means different things in SRFI 33 and SRFI 60, I have replaced SRFI 33's names `replace-bit-field` and `copy-bit-field` (`bit-field-replace` and `bit-field-copy` in Olin's revisions) with `bit-field-copy` and `bit-field-copy-same`.

The procedures that do not exist in SRFI 33 have their SRFI 60 names, with these exceptions.

* The procedure `booleans->integer` is a convenient way to specify a bitwise integer in the absence of datum syntax: it accepts an arbitrary number of boolean arguments and returns a non-negative integer.  So I gave it the short name `bits`, roughly analogous to `list`, `string`, and `vector`.

* The names `rotate-bit-field` and `reverse-bit-field` are replaced by `bit-field-rotate` and `bit-field-reverse`, in parallel with Olin's revisions.

time

2012-04-12 11:50:29

version

2