hare

commit 8369d72918381cb6243e67bcd05f3ae4a85992df
parent dcce9fe9d7835c531569c61d587818051ba8fc0a
Author: Drew DeVault <sir@cmpwn.com>
Date:   Fri,  9 Apr 2021 13:50:21 -0400

ascii: add strcasecmp

Diffstat:
M
ascii/strcmp.ha
 | 
28
++++++++++++++++++++++++++++

1 file changed, 28 insertions(+), 0 deletions(-)
diff --git a/ascii/strcmp.ha b/ascii/strcmp.ha
@@ -27,10 +27,38 @@ export fn strcmp(a: str, b: str) (int | void) = {
 	};
 };
 
+// Similar to [strcmp], but compares strings irrespective of their uppercase or
+// lowercase classification within the ASCII character set.
+export fn strcasecmp(a: str, b: str) (int | void) = {
+	let a = strings::iter(a), b = strings::iter(b);
+	for (true) {
+		let ra = match (strings::next(&a)) {
+			void => return match (strings::next(&b)) {
+				void => 0,
+				rune => -1,
+			},
+			r: rune => r,
+		};
+		let rb = match (strings::next(&b)) {
+			void => return 1,
+			r: rune => r,
+		};
+		if (!isascii(ra) || !isascii(rb)) {
+			return;
+		};
+		let ra = tolower(ra), rb = tolower(rb);
+		if (ra != rb) {
+			return ra: u32: int - rb: u32: int;
+		};
+	};
+};
+
 @test fn strcmp() void = {
 	assert(strcmp("ABC", "ABC") as int == 0);
 	assert(strcmp("ABC", "AB") as int == 1);
 	assert(strcmp("AB", "ABC") as int == -1);
 	assert(strcmp("BCD", "ABC") as int == 1);
 	assert(strcmp("ABC", "こんにちは") is void);
+	assert(strcmp("ABC", "abc") as int != 0);
+	assert(strcasecmp("ABC", "abc") as int == 0);
 };