hare

commit b1a13927adf5ce288421079ac9f9f031769117c3
parent 978d125c6a085a60ebcd1513b445131890ca534e
Author: Drew DeVault <sir@cmpwn.com>
Date:   Sun,  1 May 2022 14:25:04 +0200

io: add io::zero

A synthetic stream which always reads zeroes, equivalent to /dev/zero on
Linux.

Signed-off-by: Drew DeVault <sir@cmpwn.com>

Diffstat:
A
io/zero.ha
 | 
20
++++++++++++++++++++
M
scripts/gen-stdlib
 | 
6
++++--
M
stdlib.mk
 | 
16
++++++++++------

3 files changed, 34 insertions(+), 8 deletions(-)
diff --git a/io/zero.ha b/io/zero.ha
@@ -0,0 +1,20 @@
+// License: MPL-2.0
+// (c) 2022 Bor Grošelj Simić <bor.groseljsimic@telemach.net>
+// (c) 2021-2022 Drew DeVault <sir@cmpwn.com>
+use bytes;
+
+const _zero_vt: vtable = vtable {
+	reader = &zero_read,
+	writer = &empty_write,
+	...
+};
+
+const _zero: stream = &_zero_vt;
+
+// A [[stream]] which always reads zereos and discards any writes.
+export const zero: *stream = &_zero;
+
+fn zero_read(s: *stream, buf: []u8) (size | EOF | error) = {
+	bytes::zero(buf);
+	return len(buf);
+};
diff --git a/scripts/gen-stdlib b/scripts/gen-stdlib
@@ -768,6 +768,7 @@ gensrcs_io() {
 		tee.ha \
 		types.ha \
 		util.ha \
+		zero.ha \
 		$*
 	gen_srcs -pfreebsd io \
 		'arch+$(ARCH).ha' \
@@ -783,6 +784,7 @@ gensrcs_io() {
 		tee.ha \
 		types.ha \
 		util.ha \
+		zero.ha \
 		$*
 }
 
@@ -795,8 +797,8 @@ io() {
 			+test/limit.ha \
 			+test/stream.ha
 	fi
-	gen_ssa -plinux io strings errors
-	gen_ssa -pfreebsd io strings errors
+	gen_ssa -plinux io strings errors bytes
+	gen_ssa -pfreebsd io strings errors bytes
 }
 
 linux() {
diff --git a/stdlib.mk b/stdlib.mk
@@ -1322,7 +1322,8 @@ stdlib_io_linux_srcs = \
 	$(STDLIB)/io/stream.ha \
 	$(STDLIB)/io/tee.ha \
 	$(STDLIB)/io/types.ha \
-	$(STDLIB)/io/util.ha
+	$(STDLIB)/io/util.ha \
+	$(STDLIB)/io/zero.ha
 
 # io (+freebsd)
 stdlib_io_freebsd_srcs = \
@@ -1338,15 +1339,16 @@ stdlib_io_freebsd_srcs = \
 	$(STDLIB)/io/stream.ha \
 	$(STDLIB)/io/tee.ha \
 	$(STDLIB)/io/types.ha \
-	$(STDLIB)/io/util.ha
+	$(STDLIB)/io/util.ha \
+	$(STDLIB)/io/zero.ha
 
-$(HARECACHE)/io/io-linux.ssa: $(stdlib_io_linux_srcs) $(stdlib_rt) $(stdlib_strings_$(PLATFORM)) $(stdlib_errors_$(PLATFORM))
+$(HARECACHE)/io/io-linux.ssa: $(stdlib_io_linux_srcs) $(stdlib_rt) $(stdlib_strings_$(PLATFORM)) $(stdlib_errors_$(PLATFORM)) $(stdlib_bytes_$(PLATFORM))
 	@printf 'HAREC \t$@\n'
 	@mkdir -p $(HARECACHE)/io
 	@HARECACHE=$(HARECACHE) $(HAREC) $(HAREFLAGS) -o $@ -Nio \
 		-t$(HARECACHE)/io/io.td $(stdlib_io_linux_srcs)
 
-$(HARECACHE)/io/io-freebsd.ssa: $(stdlib_io_freebsd_srcs) $(stdlib_rt) $(stdlib_strings_$(PLATFORM)) $(stdlib_errors_$(PLATFORM))
+$(HARECACHE)/io/io-freebsd.ssa: $(stdlib_io_freebsd_srcs) $(stdlib_rt) $(stdlib_strings_$(PLATFORM)) $(stdlib_errors_$(PLATFORM)) $(stdlib_bytes_$(PLATFORM))
 	@printf 'HAREC \t$@\n'
 	@mkdir -p $(HARECACHE)/io
 	@HARECACHE=$(HARECACHE) $(HAREC) $(HAREFLAGS) -o $@ -Nio \
@@ -3382,6 +3384,7 @@ testlib_io_linux_srcs = \
 	$(STDLIB)/io/tee.ha \
 	$(STDLIB)/io/types.ha \
 	$(STDLIB)/io/util.ha \
+	$(STDLIB)/io/zero.ha \
 	$(STDLIB)/io/+test/limit.ha \
 	$(STDLIB)/io/+test/stream.ha
 
@@ -3400,16 +3403,17 @@ testlib_io_freebsd_srcs = \
 	$(STDLIB)/io/tee.ha \
 	$(STDLIB)/io/types.ha \
 	$(STDLIB)/io/util.ha \
+	$(STDLIB)/io/zero.ha \
 	$(STDLIB)/io/+test/limit.ha \
 	$(STDLIB)/io/+test/stream.ha
 
-$(TESTCACHE)/io/io-linux.ssa: $(testlib_io_linux_srcs) $(testlib_rt) $(testlib_strings_$(PLATFORM)) $(testlib_errors_$(PLATFORM))
+$(TESTCACHE)/io/io-linux.ssa: $(testlib_io_linux_srcs) $(testlib_rt) $(testlib_strings_$(PLATFORM)) $(testlib_errors_$(PLATFORM)) $(testlib_bytes_$(PLATFORM))
 	@printf 'HAREC \t$@\n'
 	@mkdir -p $(TESTCACHE)/io
 	@HARECACHE=$(TESTCACHE) $(HAREC) $(TESTHAREFLAGS) -o $@ -Nio \
 		-t$(TESTCACHE)/io/io.td $(testlib_io_linux_srcs)
 
-$(TESTCACHE)/io/io-freebsd.ssa: $(testlib_io_freebsd_srcs) $(testlib_rt) $(testlib_strings_$(PLATFORM)) $(testlib_errors_$(PLATFORM))
+$(TESTCACHE)/io/io-freebsd.ssa: $(testlib_io_freebsd_srcs) $(testlib_rt) $(testlib_strings_$(PLATFORM)) $(testlib_errors_$(PLATFORM)) $(testlib_bytes_$(PLATFORM))
 	@printf 'HAREC \t$@\n'
 	@mkdir -p $(TESTCACHE)/io
 	@HARECACHE=$(TESTCACHE) $(HAREC) $(TESTHAREFLAGS) -o $@ -Nio \