20.3.4 Interface <<textual-input-channel>>

The following syntactic bindings are exported by the library (vicare net channels).

Interface Type: <<textual-input-channel>>

Parent Type: <<channel>>

Expose the methods for all the textual input channels.

Method on <<textual-input-channel>>: <textual-terminators> message-terminators this

Method on <<textual-input-channel>>: <void> message-terminators this {terminators <textual-terminators>}

Accessor and mutator for the message termination markers. The argument terminators must represent the possible message terminators for this channel; when a terminator is received at the end of a chunk of data, the message is considered terminated.

Method on <<textual-input-channel>>: <void> recv-begin! this

Configure the channel to receive a new message. If this is not inactive: an assertion is raised.

Method on <<textual-input-channel>>: recv-end!/rbl this

Terminate the action of receiving a message. If this is not in the course of receiving a message: an assertion is raised.

Return two values:

1. A <positive-fixnum> representing the total length of the message as number of characters.
2. A (list-of <nestring>) representing the received data as reverse buffer list (RBL), including the message terminator.

After this function is applied to a channel: the channel itself is reset to inactive; so it is available to start receiving another message or to send a message.

Method on <<textual-input-channel>>: <nestring> recv-end! this

Terminate the action of receiving a message. If this is not in the course of receiving a message: an assertion is raised. If this is not in “message terminated” status: an assertion is raised. Return a string holding the full message, including the message terminator.

After this function is applied to a channel: the channel itself is reset to inactive; so it is available to start receiving another message or to send a message.

Method on <<textual-input-channel>>: <void> recv-abort! this

Abort the current operation and reset the channel to inactive. If this is not in the course of receiving a message: an assertion is raised.

Method on <<textual-input-channel>>: (or <eof> <would-block> <boolean>) recv-message-portion! this

Receive a portion of message. If this is not in the course of receiving a message: an assertion is raised.

• Return #f if a portion of message was read, and it does not terminate with a message terminator; in this case we need to call this function again to receive further message portions.
• Return #t if a portion of message was read, terminating with a configured message terminator. The channel is put in “message terminated” status.
• Return #t if the channel already read a terminator in a previous operation and is in “message terminated” status.
• Return the EOF object if EOF is read from the input device.
• Return the would–block object if a would–block object is read from the input device.
• If the message delivery timeout is expired or expires while receiving data: raise an exception.
• If the accumulated data exceeds the maximum message size: raise an exception.

Method on <<textual-input-channel>>: (or <eof> <string>) recv-full-message this

Receive a full message. When successful return a string representing the full message. If this is not inactive: an assertion is raised. If the underlying device is closed before the message is completed: return the EOF object.