hare

commit 17089efd9e51eb2ea9b835bc89350c8dbc284f6a
parent 6b38b891ce50c16b29d8edf74734ac1acc5090d0
Author: Drew DeVault <sir@cmpwn.com>
Date:   Mon, 21 Jun 2021 13:02:41 -0400

strings: add strings::join

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

Diffstat:
M
strings/concat.ha
 | 
34
++++++++++++++++++++++++++++++++++

1 file changed, 34 insertions(+), 0 deletions(-)
diff --git a/strings/concat.ha b/strings/concat.ha
@@ -32,3 +32,37 @@ export fn concat(strs: str...) str = {
 	assert(s == "");
 	free(s);
 };
+
+// Joins several strings together by placing a delimiter between them.
+export fn join(delim: str, strs: str...) str = {
+	let z = 0z;
+	for (let i = 0z; i < len(strs); i += 1) {
+		z += len(strs[i]);
+		if (i + 1 < len(strs)) {
+			z += len(delim);
+		};
+	};
+	let new: []u8 = alloc([], z);
+	for (let i = 0z; i < len(strs); i += 1) {
+		append(new, toutf8(strs[i])...);
+		if (i + 1 < len(strs)) {
+			append(new, toutf8(delim)...);
+		};
+	};
+	return fromutf8_unsafe(new[..z]);
+};
+
+@test fn join() void = {
+	let s = join(".", "a", "b", "c");
+	assert(s == "a.b.c");
+	free(s);
+
+	let s = join("", "a", "b", "c");
+	assert(s == "abc");
+	free(s);
+
+	let s = join(".");
+	assert(s == "");
+	free(s);
+
+};