authorgravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2025-09-25 11:38:38-07:00
committergravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2025-09-25 11:38:38-07:00
log14e227d8a6dd692ba0707aa070b8bac22a9a822e
tree191f4da339c891dc501d16cdda42d0a2046cb815
parent97bef50dc32e332839efe1a9c5cbf51364a431dc

std.mem: add cutLast and cutScalarLast

2 files changed, 51 insertions(+), 15 deletions(-)

lib/std/mem.zig+49-12
......@@ -1017,7 +1017,7 @@ fn lenSliceTo(ptr: anytype, comptime end: std.meta.Elem(@TypeOf(ptr))) usize {
10171017 return indexOfSentinel(array_info.child, end, ptr);
10181018 }
10191019 }
1020 return indexOfScalar(array_info.child, ptr, end) orelse array_info.len;
1020 return findScalar(array_info.child, ptr, end) orelse array_info.len;
10211021 },
10221022 else => {},
10231023 },
......@@ -1042,7 +1042,7 @@ fn lenSliceTo(ptr: anytype, comptime end: std.meta.Elem(@TypeOf(ptr))) usize {
10421042 return indexOfSentinel(ptr_info.child, s, ptr);
10431043 }
10441044 }
1045 return indexOfScalar(ptr_info.child, ptr, end) orelse ptr.len;
1045 return findScalar(ptr_info.child, ptr, end) orelse ptr.len;
10461046 },
10471047 },
10481048 else => {},
......@@ -1229,7 +1229,7 @@ pub fn allEqual(comptime T: type, slice: []const T, scalar: T) bool {
12291229/// Remove a set of values from the beginning of a slice.
12301230pub fn trimStart(comptime T: type, slice: []const T, values_to_strip: []const T) []const T {
12311231 var begin: usize = 0;
1232 while (begin < slice.len and indexOfScalar(T, values_to_strip, slice[begin]) != null) : (begin += 1) {}
1232 while (begin < slice.len and findScalar(T, values_to_strip, slice[begin]) != null) : (begin += 1) {}
12331233 return slice[begin..];
12341234}
12351235
......@@ -1243,7 +1243,7 @@ pub const trimLeft = trimStart;
12431243/// Remove a set of values from the end of a slice.
12441244pub fn trimEnd(comptime T: type, slice: []const T, values_to_strip: []const T) []const T {
12451245 var end: usize = slice.len;
1246 while (end > 0 and indexOfScalar(T, values_to_strip, slice[end - 1]) != null) : (end -= 1) {}
1246 while (end > 0 and findScalar(T, values_to_strip, slice[end - 1]) != null) : (end -= 1) {}
12471247 return slice[0..end];
12481248}
12491249
......@@ -1258,8 +1258,8 @@ pub const trimRight = trimEnd;
12581258pub fn trim(comptime T: type, slice: []const T, values_to_strip: []const T) []const T {
12591259 var begin: usize = 0;
12601260 var end: usize = slice.len;
1261 while (begin < end and indexOfScalar(T, values_to_strip, slice[begin]) != null) : (begin += 1) {}
1262 while (end > begin and indexOfScalar(T, values_to_strip, slice[end - 1]) != null) : (end -= 1) {}
1261 while (begin < end and findScalar(T, values_to_strip, slice[begin]) != null) : (begin += 1) {}
1262 while (end > begin and findScalar(T, values_to_strip, slice[end - 1]) != null) : (end -= 1) {}
12631263 return slice[begin..end];
12641264}
12651265
......@@ -3145,15 +3145,15 @@ test cutSuffix {
31453145 try testing.expectEqual(null, cutSuffix(u8, "foobar", "baz"));
31463146}
31473147
3148/// Returns slice of `haystack` before and after `needle`, or `null` if not
3149/// found.
3148/// Returns slice of `haystack` before and after first occurrence of `needle`,
3149/// or `null` if not found.
31503150///
31513151/// See also:
31523152/// * `cutScalar`
31533153/// * `split`
31543154/// * `tokenizeAny`
31553155pub fn cut(comptime T: type, haystack: []const T, needle: []const T) ?struct { []const T, []const T } {
3156 const index = indexOf(T, haystack, needle) orelse return null;
3156 const index = find(T, haystack, needle) orelse return null;
31573157 return .{ haystack[0..index], haystack[index + needle.len ..] };
31583158}
31593159
......@@ -3164,15 +3164,33 @@ test cut {
31643164 try testing.expectEqualStrings(" c", after);
31653165}
31663166
3167/// Returns slice of `haystack` before and after `needle`, or `null` if not
3168/// found.
3167/// Returns slice of `haystack` before and after last occurrence of `needle`,
3168/// or `null` if not found.
3169///
3170/// See also:
3171/// * `cut`
3172/// * `cutScalarLast`
3173pub fn cutLast(comptime T: type, haystack: []const T, needle: []const T) ?struct { []const T, []const T } {
3174 const index = findLast(T, haystack, needle) orelse return null;
3175 return .{ haystack[0..index], haystack[index + needle.len ..] };
3176}
3177
3178test cutLast {
3179 try testing.expectEqual(null, cutLast(u8, "a b c", "B"));
3180 const before, const after = cutLast(u8, "a be c be d", "be") orelse return error.TestFailed;
3181 try testing.expectEqualStrings("a be c ", before);
3182 try testing.expectEqualStrings(" d", after);
3183}
3184
3185/// Returns slice of `haystack` before and after first occurrence `needle`, or
3186/// `null` if not found.
31693187///
31703188/// See also:
31713189/// * `cut`
31723190/// * `splitScalar`
31733191/// * `tokenizeScalar`
31743192pub fn cutScalar(comptime T: type, haystack: []const T, needle: T) ?struct { []const T, []const T } {
3175 const index = indexOfScalar(T, haystack, needle) orelse return null;
3193 const index = findScalar(T, haystack, needle) orelse return null;
31763194 return .{ haystack[0..index], haystack[index + 1 ..] };
31773195}
31783196
......@@ -3183,6 +3201,25 @@ test cutScalar {
31833201 try testing.expectEqualStrings(" c", after);
31843202}
31853203
3204/// Returns slice of `haystack` before and after last occurrence of `needle`,
3205/// or `null` if not found.
3206///
3207/// See also:
3208/// * `cut`
3209/// * `splitScalar`
3210/// * `tokenizeScalar`
3211pub fn cutScalarLast(comptime T: type, haystack: []const T, needle: T) ?struct { []const T, []const T } {
3212 const index = findScalarLast(T, haystack, needle) orelse return null;
3213 return .{ haystack[0..index], haystack[index + 1 ..] };
3214}
3215
3216test cutScalarLast {
3217 try testing.expectEqual(null, cutScalarLast(u8, "a b c", 'B'));
3218 const before, const after = cutScalarLast(u8, "a b c b d", 'b') orelse return error.TestFailed;
3219 try testing.expectEqualStrings("a b c ", before);
3220 try testing.expectEqualStrings(" d", after);
3221}
3222
31863223/// Delimiter type for tokenization and splitting operations.
31873224pub const DelimiterType = enum { sequence, any, scalar };
31883225
src/main.zig+2-3
......@@ -1057,9 +1057,8 @@ fn buildOutputType(
10571057 fatal("unexpected end-of-parameter mark: --", .{});
10581058 }
10591059 } else if (mem.eql(u8, arg, "--dep")) {
1060 var it = mem.splitScalar(u8, args_iter.nextOrFatal(), '=');
1061 const key = it.first();
1062 const value = if (it.peek() != null) it.rest() else key;
1060 const next_arg = args_iter.nextOrFatal();
1061 const key, const value = mem.cutScalar(u8, next_arg, '=') orelse .{ next_arg, next_arg };
10631062 if (mem.eql(u8, key, "std") and !mem.eql(u8, value, "std")) {
10641063 fatal("unable to import as '{s}': conflicts with builtin module", .{
10651064 key,