Adding initial pico-ice support.

pico-ice/platform.fs

@@ -0,0 +1,50 @@
+\ Copyright 2023 Bradley D. Nelson
+\
+\ Licensed under the Apache License, Version 2.0 (the "License");
+\ you may not use this file except in compliance with the License.
+\ You may obtain a copy of the License at
+\
+\     http://www.apache.org/licenses/LICENSE-2.0
+\
+\ Unless required by applicable law or agreed to in writing, software
+\ distributed under the License is distributed on an "AS IS" BASIS,
+\ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+\ See the License for the specific language governing permissions and
+\ limitations under the License.
+
+( Add a yielding task so pause yields )
+internals definitions
+: yield-step   raw-yield yield ;
+' yield-step 100 100 task yield-task
+yield-task start-task
+forth definitions
+
+( Initial file handles )
+0 constant stdin
+1 constant stdout
+2 constant stderr
+
+( Set up Basic I/O )
+also internals definitions
+: setup-saving-base ;  ( TODO: implement. )
+variable last-key  -1 last-key !
+forth definitions internals
+: default-type ( a n -- ) stderr write-file throw ;
+: default-key? ( -- f )
+   last-key @ 0< if 1000 getchar_timeout_us last-key ! then
+   last-key @ 0< 0=
+;
+: default-key ( -- ch )
+   begin default-key? 0= while pause repeat
+   last-key @ -1 last-key !
+;
+previous
+
+' default-type is type
+' default-key is key
+' default-key? is key?
+' raw-terminate is terminate
+-1 echo !
+
+( Setup entry )
+internals : ok   ." uEforth" raw-ok ; forth