.. index:: repl, terminal hooks, hooks,uart handlers


The Mecrisp REPL
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Terminal handlers
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emit, emit?, key and key? are the UART handlers.

If you wish to use blocking IO, you can set hook-emit? and hook-key? statically to true.


Repl Maximum Character Length
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You can change the accepted length in forth-core.s for "Maximaleeingabe" which is currently set to 200 characters.

Ledcomm Example from Matthias
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https://sourceforge.net/p/mecrisp/discussion/general/thread/e29549a8d5/?limit=25#4afd/6b1e  [matthias.koch]_


::

 key? ( -- ? ) is giving you a flag meaning if there is (at least) one character in the receive buffer.
 key ( -- c ) is waiting until a character is received (it calls key? internally in a loop) and gives back that character.
 
 The hooks are just vectors, accepting a pointer to a definition.
 
 hook-key takes a definition which works as "key" and hook-key? takes a definition which works as "key?"
 
 Look at this snipplet:
 
 0 variable tx-puffer
 0 variable rx-puffer
 
 Communication is done from/to buffer variables driven by timers/interrupts
 
 Then wire the buffers in accordingly:
 
 : ledcomm-key? ( -- ? ) rx-puffer @ 0<> ;
 : ledcomm-key ( -- c ) begin ledcomm-key? until rx-puffer @ 0 rx-puffer ! ;
 : ledcomm-emit? ( -- ? ) tx-puffer @ 0= ;
 : ledcomm-emit ( c -- ) begin ledcomm-emit? until tx-puffer ! ;
 
 Switch terminal to new definitions:
 
 ['] ledcomm-key? hook-key? !
 ['] ledcomm-key hook-key !
 ['] ledcomm-emit? hook-emit? !
 ['] ledcomm-emit hook-emit !