diff options
| -rw-r--r-- | txr.1 | 37 |
1 files changed, 25 insertions, 12 deletions
@@ -11152,6 +11152,31 @@ and .code from fields are the objects denoted by these expressions. +.NP* Buffer Literals + +.meIP <> #b' hex-data ' + +The notation +.code #b' +introduces a buffer object: a data representation for a +block of bytes. This +.code #b' +prefix must be followed +by a data section and a closing quote. +The data section consists of hexadecimal digits, among which +may be interspersed whitespace: tabs, spaces and newlines. +There must be an even number of digits, or else the +notation is ill-formed. The whitespace is ignored, and +pairs of successive hex digits specify bytes. +If there are no hex digits, then a zero length buffer +is specified. + +Buffers may be constructed by the +.code make-buffer +function, and other means such as the +.code ffi-get +function. + .coNP The @ .. notation In \*(TL, there is a special "dotdot" notation consisting of a pair of dots. This can be written between successive atoms or compound expressions, and is a @@ -52086,18 +52111,6 @@ Buffers are vector-like objects specialized for holding binary data. Buffers support operations specialized toward the encoding of Lisp values into machine-oriented data types, and decoding such data types into Lisp values. -Buffers are of type -.code buf -and, have a printed representation consisting of a -.code #b' -("hash b quote") -prefix, immediately followed by data, followed by a closing quote. -The data consists of hexadecimal digits, which may be separated by -whitespace: newlines, tabs and spaces. -If no hexadecimal digits occur, the notation denotes a zero-length buffer. -There must be an even number of hexadecimal digits; if there is an odd number, -the notation is ill-formed. Successive pairs of hex digits denote bytes. - Buffers are particularly useful in conjunction with the Foreign Function Interface (FFI), since they can be used to prepare arbitrary data which can be passed into and out of a function by pointer. They are also useful for |