Guile’s binary and textual port interface was heavily inspired by R6RS, so many R6RS port interfaces are documented elsewhere. Note that R6RS ports are not disjoint from Guile’s native ports, so Guile-specific procedures will work on ports created using the R6RS API, and vice versa. Also note that in Guile, all ports are both textual and binary. See Input and Output, for more on Guile’s core port API. The R6RS ports module wraps Guile’s I/O routines in a helper that will translate native Guile exceptions to R6RS conditions; See I/O Conditions, for more. See R6RS File Ports, for documentation on the R6RS file port interface.
Note: The implementation of this R6RS API is not complete yet.
See Binary I/O, for documentation.
Return the end-of-file (EOF) object.
(eof-object? (eof-object)) ⇒ #t
See Ports, for documentation.
Return a transcoder associated with the encoding of port. See Encoding, and See Transcoders.
Return #t if port appears to be a binary port, else return
#f. Note that Guile does not currently distinguish between
binary and textual ports, so this predicate is not a reliable indicator
of whether the port was created as a binary port. Currently, it returns
#t if and only if the port encoding is “ISO-8859-1”, because
Guile uses this encoding when creating a binary port. See Encoding,
for more details.
Return #t if port appears to be a textual port, else return
#f. Note that Guile does not currently distinguish between
binary and textual ports, so this predicate is not a reliable indicator
of whether the port was created as a textual port. Currently, it always
returns #t, because all ports can be used for textual I/O in
Guile. See Encoding, for more details.
The transcoded-port procedure
returns a new textual port with the specified transcoder.
Otherwise the new textual port’s state is largely the same as
that of binary-port.
If binary-port is an input port, the new textual
port will be an input port and
will transcode the bytes that have not yet been read from
binary-port.
If binary-port is an output port, the new textual
port will be an output port and
will transcode output characters into bytes that are
written to the byte sink represented by binary-port.
As a side effect, however, transcoded-port
closes binary-port in
a special way that allows the new textual port to continue to
use the byte source or sink represented by binary-port,
even though binary-port itself is closed and cannot
be used by the input and output operations described in this
chapter.
Equivalent to (seek port 0 SEEK_CUR). See Random Access.
Return #t is port supports port-position.
Equivalent to (seek port offset SEEK_SET).
See Random Access.
Return #t is port supports set-port-position!.
Equivalent to (eof-object? (lookahead-u8 input-port)).
Returns a fresh binary input port connected to standard input, or a
binary output port connected to the standard output or standard error,
respectively. Whether the port supports the port-position and
set-port-position! operations is implementation-dependent.
See Bytevector Ports.
See Custom Ports.
See Custom Ports.
See Binary I/O.
See Textual I/O.
Reads an external representation from textual-input-port and returns the
datum it represents. The get-datum procedure returns the next
datum that can be parsed from the given textual-input-port, updating
textual-input-port to point exactly past the end of the external
representation of the object.
Any interlexeme space (comment or whitespace, see Scheme Syntax: Standard and Guile Extensions) in the input is first skipped. If an end of file occurs after the interlexeme space, the end-of-file object is returned.
If a character inconsistent with an external representation is
encountered in the input, an exception with condition types
&lexical and &i/o-read is raised. Also, if the end of
file is encountered after the beginning of an external representation,
but the external representation is incomplete and therefore cannot be
parsed, an exception with condition types &lexical and
&i/o-read is raised.
datum should be a datum value. The put-datum procedure
writes an external representation of datum to
textual-output-port. The specific external representation is
implementation-dependent. However, whenever possible, an implementation
should produce a representation for which get-datum, when reading
the representation, will return an object equal (in the sense of
equal?) to datum.
Note: Not all datums may allow producing an external representation for which
get-datumwill produce an object that is equal to the original. Specifically, NaNs contained in datum may make this impossible.
Note: The
put-datumprocedure merely writes the external representation, but no trailing delimiter. Ifput-datumis used to write several subsequent external representations to an output port, care should be taken to delimit them properly so they can be read back in by subsequent calls toget-datum.