diff options
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 94 |
1 files changed, 88 insertions, 6 deletions
@@ -9252,10 +9252,10 @@ reserved set, encodes to .codn %2B . .coIP :frombase64 -Decode from the Base 64 encoding described in RFC 4648. +Decode from the Base64 encoding described in RFC 4648. .coIP :tobase64 -Encodes to the RFC 4648 Base 64 encoding. +Encodes to the RFC 4648 Base64 encoding. .coIP :tonumber Converts strings to numbers. Strings that contain a period, @@ -52381,15 +52381,15 @@ The .code base64-encode function converts the UTF-8 representation of .meta string -to Base 64 and returns that representation as a string. +to Base64 and returns that representation as a string. The .code base64-decode functions performs the opposite conversion; it extracts the -bytes encoded in a Base 64 string, and decodes them as UTF-8 +bytes encoded in a Base64 string, and decodes them as UTF-8 to return a character string. -The Base 64 encoding divides the UTF-8 representation into groups of +The Base64 encoding divides the UTF-8 representation into groups of six bits, each representing the values 0 to 63. Each value is then mapped to the characters .code A @@ -52423,11 +52423,93 @@ If the .meta column-width argument is passed to .codn base64-encode , -then the Base 64 encoded string, unless empty, contains newline +then the Base64 encoded string, unless empty, contains newline characters, which divide it into lines which are .meta column-width long, except possibly for the last line. +.coNP Functions @ base64-stream-enc and @ base64-stream-dec +.synb +.mets (base64-stream-enc < out < in >> [ nbytes <> [ column-width ]]) +.mets (base64-stream-dec < out << in ) +.syne +.desc +The +.code base64-stream-enc +and +.code base64-stream-dec +perform, respectively, bulk Base64 encoding and decoding between streams. + +The +.meta in +and +.meta out +arguments must be stream objects. +The +.meta out +stream must support output. In the decode operation, it must support +byte output. +The +.meta in +stream must support input. In in the encode operation it must support +byte input. + +The +.code base64-stream-enc +function reads a sequence of bytes from the +.meta in +stream and writes characters to the +.meta out +stream comprising the Base64 encoding of that sequence. If the +.meta nbytes +argument is specified, it must be a non-negative integer. At most +.meta nbytes +bytes will be read from the +.meta in +stream. If +.meta nbytes +is omitted, then the operation will read from the +.meta in +stream without limit, until that stream indicates that no more bytes +are available. + +The optional +.meta column-with +argument influences the formatting of Base64 output, in the same manner +as documented for the +.code base64-encode +function. + +The +.code base64-stream-dec +function reads the characters of a Base64 encoding from the +.meta in +stream and writes the corresponding byte sequence to the +.meta out +stream. It keeps reading and decoding until it encounters the end of the +stream, or a character not used in Base64: a character that is not whitespace +according to +.codn chr-isspace , +isn't any of the Base64 coding characters (not an alphanumeric character, +and not one of the characters +.codn + , +.code / +or +.codn = . +If the function stops due to a non-Base64 character, that character is +pushed back into the +.meta in +stream. + +The +.code base64-stream-enc +function returns +.code t +if the +.meta nbytes +argument is omitted. If the argument is specified, +it returns the number of bytes that have been encoded. + .SS* Filter Module The filter module provides a trie (pronounced "try") data structure, which is suitable for representing dictionaries for efficient filtering. |