commit 8dfcb448c36994abe236a01ea556f032e2455ac0
parent b180762cbe74c58a28b05778b0e28b8f87030f6d
Author: Virgil Dupras <hsoft@hardcoded.net>
Date: Sun, 27 Nov 2022 12:05:19 -0500
sys/io: add MemIO struct
Diffstat:
4 files changed, 34 insertions(+), 0 deletions(-)
diff --git a/fs/doc/io.txt b/fs/doc/io.txt
@@ -104,6 +104,18 @@ If, for example, you want to create a CRC32 calculator, you'd do:
mycrc32io otheriohandle IO :spit
mycrc32io SumIO res ^ .x \ prints crc32 of otheriohandle's contents
+## MemIO
+
+MemIO is a structure that extends IO and provides read/write capability to a
+memory area. It is unbounded and simply starts at a particular address, from
+which you start reading or writing from/to. This is often used as a way to use
+IO's nice formatting capabilities directly to memory.
+
+ptr -- where the MemIO is currently pointing
+
+:new ( a -- hdl )
+ Allocate a new MemIO pointing to address a
+
## SystemIn and SystemOut
SystemIn and SystemOut are structures that wrap around "key" and "emit",
diff --git a/fs/sys/io.fs b/fs/sys/io.fs
@@ -52,3 +52,13 @@ extends IO struct[ SumIO
0 ( putback ) , ['] _ioerr , ['] _writebuf , ['] drop , ['] drop ,
( 'fn ) , 0 , ;
]struct
+
+extends IO struct[ MemIO
+ sfield ptr
+ : _readbuf ( n hdl -- a? read-n ) ptr swap ;
+ : _writebuf ( a n hdl -- written-n )
+ ptr ( src n dst ) over >r swap move r> ;
+ : :new ( a -- hdl )
+ here 0 ( putback ) , ['] _readbuf , ['] _writebuf , ['] drop , ['] drop ,
+ swap ( a ) , ;
+]struct
diff --git a/fs/tests/sys/all.fs b/fs/tests/sys/all.fs
@@ -1,2 +1,3 @@
\ Run all sys test suites
+f<< /tests/sys/io.fs
f<< /tests/sys/file.fs
diff --git a/fs/tests/sys/io.fs b/fs/tests/sys/io.fs
@@ -0,0 +1,11 @@
+?f<< /tests/harness.fs
+testbegin
+\ Tests for sys/io
+create mymem ," hello there!"
+mymem MemIO :new structbind MemIO memio
+here 12 memio :read
+mymem here 12 []= #
+mymem to memio ptr
+S" foobar" dup memio :puts ( s )
+c@+ ( a len ) mymem rot> []= #
+testend
