hare

commit 654ef204a274cccc27328d100175390b72ec40d6
parent 34a6ab32985cdf6916c447cc7eec28214c683681
Author: Thomas Bracht Laumann Jespersen <t@laumann.xyz>
Date:   Wed, 17 Nov 2021 09:14:39 +0100

bytes: Add hasprefix() and hassuffix()

Basically copies the byte slice comparison implementation from
strings::has_prefix() and strings::has_suffix(), and have the string
functions just call the byte functions.

Signed-off-by: Thomas Bracht Laumann Jespersen <t@laumann.xyz>

Diffstat:
M
bytes/contains.ha
 | 
50
++++++++++++++++++++++++++++++++++++++++++++++++++
M
strings/suffix.ha
 | 
49
++++---------------------------------------------

2 files changed, 54 insertions(+), 45 deletions(-)
diff --git a/bytes/contains.ha b/bytes/contains.ha
@@ -5,3 +5,53 @@ case b: u8 =>
 case b: []u8 =>
 	yield !(index_slice(haystack, b) is void);
 };
+
+// Returns true if "in" has the given prefix, false otherwise
+export fn hasprefix(in: []u8, prefix: []u8) bool = {
+	return if (len(in) < len(prefix)) false
+		else equal(in[..len(prefix)], prefix);
+};
+
+@test fn hasprefix() void = {
+	const cases: []([]u8, []u8, bool) = [
+		([], [], true),
+		([0], [], true),
+		([], [0], false),
+		([1, 2, 3], [1, 2], true),
+		([1, 2, 3], [1, 1], false),
+		([1, 2, 3], [1, 2, 3, 4], false),
+	];
+
+	for (let i = 0z; i < len(cases); i += 1) {
+		let s = cases[i].0;
+		let prefix = cases[i].1;
+		let expected = cases[i].2;
+		let actual = hasprefix(s, prefix);
+		assert(actual == expected);
+	};
+};
+
+// Returns true if "in" has the given suffix, false otherwise
+export fn hassuffix(in: []u8, suffix: []u8) bool = {
+	return if (len(in) < len(suffix)) false
+		else equal(in[len(in) - len(suffix)..], suffix);
+};
+
+@test fn hassuffix() void = {
+	const cases: []([]u8, []u8, bool) = [
+		([], [], true),
+		([0], [], true),
+		([], [0], false),
+		([1, 2, 3], [2, 3], true),
+		([1, 2, 3], [2, 2], false),
+		([1, 2, 3, 4], [2, 3, 4], true),
+	];
+
+	for (let i = 0z; i < len(cases); i += 1) {
+		let s = cases[i].0;
+		let prefix = cases[i].1;
+		let expected = cases[i].2;
+		let actual = hassuffix(s, prefix);
+		assert(actual == expected);
+	};
+};
diff --git a/strings/suffix.ha b/strings/suffix.ha
@@ -1,48 +1,7 @@
-// Returns true if 'in' has the given prefix.
-export fn has_prefix(in: str, prefix: str) bool = {
-	let a = toutf8(in), b = toutf8(prefix);
-	if (len(a) < len(b)) {
-		return false;
-	};
-	for (let i = 0z; i < len(b); i += 1) {
-		if (a[i] != b[i]) {
-			return false;
-		};
-	};
-	return true;
-};
-
-@test fn prefix() void = {
-	assert(has_prefix("abcde", "abc"));
-	assert(has_prefix("abcde", "abcde"));
-	assert(has_prefix("abcde", ""));
-	assert(has_prefix("", ""));
-	assert(!has_prefix("abcde", "cde"));
-	assert(!has_prefix("abcde", "abcdefg"));
-	assert(!has_prefix("", "abc"));
-};
+use bytes;
 
 // Returns true if 'in' has the given prefix.
-export fn has_suffix(in: str, suff: str) bool = {
-	let a = toutf8(in), b = toutf8(suff);
-	if (len(a) < len(b)) {
-		return false;
-	};
-	for (let i = 0z; i < len(b); i += 1) {
-		if (a[len(a) - len(b) + i] != b[i]) {
-			return false;
-		};
-	};
-	return true;
-};
+export fn has_prefix(in: str, prefix: str) bool = bytes::hasprefix(toutf8(in), toutf8(prefix));
 
-@test fn suffix() void = {
-	assert(has_suffix("abcde", "cde"));
-	assert(has_suffix("abcde", "abcde"));
-	assert(has_suffix("abcde", ""));
-	assert(has_suffix("", ""));
-	assert(has_suffix("abcde", ""));
-	assert(!has_suffix("abcde", "abc"));
-	assert(!has_suffix("abcde", "fabcde"));
-	assert(!has_suffix("", "abc"));
-};
+// Returns true if 'in' has the given prefix.
+export fn has_suffix(in: str, suff: str) bool = bytes::hassuffix(toutf8(in), toutf8(suff));