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doco ports verbiage
From: |
Kevin Ryde |
Subject: |
doco ports verbiage |
Date: |
Thu, 12 Jun 2003 10:56:29 +1000 |
User-agent: |
Gnus/5.090019 (Oort Gnus v0.19) Emacs/21.2 (gnu/linux) |
This is in the interests of reducing duplication. For with- and
call-with- I found it a bit hard to see quite what was going on with
five rather similar chunks of text.
* scheme-io.texi (File Ports): Describe call-with-input-file and
call-with-output-file together. Describe with-input-from-file,
with-output-to-file and with-error-to-file together.
(Closing): Describe close-input-port and close-output-port together,
tweak the wording slightly.
The words are slightly rearranged in support of this, but what's
specified is not changed.
- Scheme Procedure: call-with-input-file filename proc
- Scheme Procedure: call-with-output-file filename proc
Open FILENAME for input or output, and call `(PROC port)' with the
resulting port. Return the value returned by PROC.
For input, FILENAME must exist. For output, if FILENAME already
exists the behaviour is unspecified. In both cases if FILENAME
cannot be opened an error is signalled.
When PROC returns, the port is closed. If PROC does not return
(eg. if it throws an error), then the port might not be closed
automatically, though it will be garbage collected in the usual
way if not otherwise referenced.
- Scheme Procedure: with-input-from-file filename thunk
- Scheme Procedure: with-output-to-file filename thunk
- Scheme Procedure: with-error-to-file filename thunk
Open FILENAME and call `(THUNK)' with the port setup as
respectively the `current-input-port', `current-output-port', or
`current-error-port'. Return the value returned by THUNK.
For input, FILENAME must exist. For output and error output, if
FILENAME already exists the behaviour is unspecified. In all
cases if FILENAME cannot be opened, an error is signalled.
When THUNK returns, the port is closed and the previous setting of
the respective current port is restored. If THUNK does not return
(eg. if it throws an error), then what happens to the ports is
unspecified.
- Scheme Procedure: close-input-port port
- Scheme Procedure: close-output-port port
- C Function: scm_close_input_port (port)
- C Function: scm_close_output_port (port)
Close the specified input or output PORT. An exception may be
raised if an error occurs while closing. If PORT is already
closed, nothing is done. The return value is unspecified.
See also *Note close: Ports and File Descriptors, for a procedure
which can close file descriptors.
scheme-io.texi.ports.diff
Description: Text document
- doco ports verbiage,
Kevin Ryde <=