hare

commit aaa6b93379bb4b064238da67f298e6dbb91e7a56
parent c08cc7e751106913fe3c146f9091fb4b84ddc454
Author: Drew DeVault <sir@cmpwn.com>
Date:   Sun,  7 Feb 2021 12:01:16 -0500

strings::concat

Diffstat:
A
strings/concat.ha
 | 
42
++++++++++++++++++++++++++++++++++++++++++

1 file changed, 42 insertions(+), 0 deletions(-)
diff --git a/strings/concat.ha b/strings/concat.ha
@@ -0,0 +1,42 @@
+use rt;
+use types;
+
+// Concatenates two or more strings. The caller must free the return value.
+export fn concat(strs: str...) str = {
+	let z = 0z;
+	for (let i = 0z; i < len(strs); i += 1z) {
+		z += len(strs[i]);
+	};
+	let new = alloc([]u8, [], z + 1z);
+	let buf = new: *[*]u8;
+	for (let i = 0z, j = 0z; i < len(strs); i += 1z) {
+		rt::memcpy(&buf[j], strs[i]: *const char: *[*]u8, len(strs[i]));
+		j += len(strs[i]);
+	};
+	buf[z + 1z] = 0u8;
+	(&new: *types::string).length = z;
+	return *(&new: *str);
+};
+
+@test fn concat() void = {
+	let s = concat("hello ", "world");
+	assert(s == "hello world");
+	assert((s: *const char: *[*]u8)[len(s)] == 0u8);
+	free(s);
+
+	s = concat("hello", " ", "world");
+	assert(s == "hello world");
+	free(s);
+
+	s = concat("hello", "", "world");
+	assert(s == "helloworld");
+	free(s);
+
+	s = concat("", "");
+	assert(s == "");
+	free(s);
+
+	s = concat();
+	assert(s == "");
+	free(s);
+};