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Section 8.10.3.4: |
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This class implements a connection to the standard operating system error channel -- for output only! (see also the class OUT for normal program output).
The following routine is required to be implemented for this class in accordance with the specification given in $OUT_DEVICE :-
Since the standard error channel is only for output, this will vacuously return true for this class.
This feature produces a new connection to the program environment standard error channel for use in output of text to that channel.
create | : SAME |
This is vacuously true for creation without arguments.
The result, not being of an optional type, is the newly created connection; the post-condition is true.
This creation creates a new connection to the program environment standard error channel for appending text data only.
This is the first of four variants of the channel append operation. It appends the single character argument to the channel.
This operation appends the character argument to the program environment defined standard error channel as a code which is assumed to be in the program environment default encoding and repertoire. If this is not the case then the result is undefined.
This second variant of the channel append operation first appends the single character argument to the channel and then returns the connection.
Note that the name of the formal operation has been changed since over-loading is not permitted in vdm-sl.
This operation appends the character argument to the program environment standard error channel as a code which is assumed to be in the program environment default encoding and repertoire. If this is not the case then the result is undefined although self is returned irrespective of this.
This variant of the channel append operation takes a text string argument - which it appends to the channel.
Note that the name of the formal operation has been changed since over-loading is not permitted in vdm-sl.
This operation appends the string argument to the program environment defined standard error channel as a sequence of codes which are assumed to be in the program environment default encoding and repertoire (see also STR::index_lib). If this is not the case then the result is undefined.
This final variant of the channel append operation first appends the string argument to the channel and then returns the connection.
Note that the name of the formal operation has been changed since over-loading is not permitted in vdm-sl.
This operation appends the given string to the program environment standard error channel as a sequence of codes which are assumed to be in the program environment default encoding and repertoire (see also STR::index_lib). If this is not the case then the result is undefined although self is returned irrespective of this.
This feature ensures that any pending output to the channel has been delivered.
This is vacuously true.
Any output which has been sent to the channel since either it was opened or the most recent previous call of this routine will be forced out before any other output can be queued for the channel. It is equivalent to a synchronise of the channel between program and environment.
This routine flushes any output queue/buffer which may be associated with the channel, ensuring that channel and program are synchronised.
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Keith
Hopper. Page last modified: Friday, 17 November 2000. |
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