You can edit this page using wiki syntax for markup.

Article contents:== Outdated CHICKEN release This is a manual page for an old and unsupported version of CHICKEN. If you are still using it, please consider migrating to the latest version. You can find the manual for the latest release [[/manual|here]]. [[tags: manual]] [[toc:]] == Unit ports This unit contains various extended port definitions. This unit is used by default, unless the program is compiled with the {{-explicit-use}} option. === Input/output port extensions ==== with-output-to-port <procedure>(with-output-to-port PORT THUNK)</procedure> Call procedure {{THUNK}} with the current output-port temporarily bound to {{PORT}}. ==== make-input-port <procedure>(make-input-port READ READY? CLOSE [PEEK])</procedure> Returns a custom input port. Common operations on this port are handled by the given parameters, which should be procedures of no arguments. {{READ}} is called when the next character is to be read and should return a character or {{#!eof}}. {{READY?}} is called when {{char-ready?}} is called on this port and should return {{#t}} or {{#f}}. {{CLOSE}} is called when the port is closed. {{PEEK}} is called when {{peek-char}} is called on this port and should return a character or {{#!eof}}. if the argument {{PEEK}} is not given, then {{READ}} is used instead and the created port object handles peeking automatically (by calling {{READ}} and buffering the character). ==== make-output-port <procedure>(make-output-port WRITE CLOSE [FLUSH])</procedure> Returns a custom output port. Common operations on this port are handled by the given parameters, which should be procedures. {{WRITE}} is called when output is sent to the port and receives a single argument, a string. {{CLOSE}} is called when the port is closed and should be a procedure of no arguments. {{FLUSH}} (if provided) is called for flushing the output port. ==== with-error-output-to-port <procedure>(with-error-output-to-port PORT THUNK)</procedure> Call procedure {{THUNK}} with the current error output-port temporarily bound to {{PORT}}. ==== with-input-from-port <procedure>(with-input-from-port PORT THUNK)</procedure> Call procedure {{THUNK}} with the current input-port temporarily bound to {{PORT}}. === String-port extensions ==== call-with-input-string <procedure>(call-with-input-string STRING PROC)</procedure> Calls the procedure {{PROC}} with a single argument that is a string-input-port with the contents of {{STRING}}. ==== call-with-output-string <procedure>(call-with-output-string PROC)</procedure> Calls the procedure {{PROC}} with a single argument that is a string-output-port. Returns the accumulated output-string. ==== with-input-from-string <procedure>(with-input-from-string STRING THUNK)</procedure> Call procedure {{THUNK}} with the current input-port temporarily bound to an input-string-port with the contents of {{STRING}}. ==== with-output-to-string <procedure>(with-output-to-string THUNK)</procedure> Call procedure {{THUNK}} with the current output-port temporarily bound to a string-output-port and return the accumulated output string. === Port iterators ==== port-for-each <procedure>(port-for-each FN THUNK)</procedure> Apply {{FN}} to successive results of calling the zero argument procedure {{THUNK}} until it returns {{#!eof}}, discarding the results. ==== port-map <procedure>(port-map FN THUNK)</procedure> Apply {{FN}} to successive results of calling the zero argument procedure {{THUNK}} until it returns {{#!eof}}, returning a list of the collected results. ==== port-fold <procedure>(port-map FN ACC THUNK)</procedure> Apply {{FN}} to successive results of calling the zero argument procedure {{THUNK}}, passing the {{ACC}} value as the second argument. The {{FN}} result becomes the new {{ACC}} value. When {{THUNK}} returns {{#!eof}}, the last {{FN}} result is returned. === Funky ports ==== make-broadcast-port <procedure>(make-broadcast-port PORT ...)</procedure> Returns a custom output port that emits everything written into it to the ports given as {{PORT ...}}. Closing the broadcast port does not close any of the argument ports. ==== make-concatenated-port <procedure>(make-concatenated-port PORT1 PORT2 ...)</procedure> Returns a custom input port that reads its input from {{PORT1}}, until it is empty, then from {{PORT2}} and so on. Closing the concatenated port does not close any of the argument ports. Previous: [[Unit data-structures]] Next: [[Unit files]] Description of your changes:

I would like to authenticate

Spam control

What do you get when you subtract 17 from 7?