std.mem: add cutLast and cutScalarLast

This commit is contained in:
Andrew Kelley 2025-09-25 11:38:38 -07:00
parent 97bef50dc3
commit 14e227d8a6
2 changed files with 51 additions and 15 deletions

View File

@ -1017,7 +1017,7 @@ fn lenSliceTo(ptr: anytype, comptime end: std.meta.Elem(@TypeOf(ptr))) usize {
return indexOfSentinel(array_info.child, end, ptr);
}
}
return indexOfScalar(array_info.child, ptr, end) orelse array_info.len;
return findScalar(array_info.child, ptr, end) orelse array_info.len;
},
else => {},
},
@ -1042,7 +1042,7 @@ fn lenSliceTo(ptr: anytype, comptime end: std.meta.Elem(@TypeOf(ptr))) usize {
return indexOfSentinel(ptr_info.child, s, ptr);
}
}
return indexOfScalar(ptr_info.child, ptr, end) orelse ptr.len;
return findScalar(ptr_info.child, ptr, end) orelse ptr.len;
},
},
else => {},
@ -1229,7 +1229,7 @@ pub fn allEqual(comptime T: type, slice: []const T, scalar: T) bool {
/// Remove a set of values from the beginning of a slice.
pub fn trimStart(comptime T: type, slice: []const T, values_to_strip: []const T) []const T {
var begin: usize = 0;
while (begin < slice.len and indexOfScalar(T, values_to_strip, slice[begin]) != null) : (begin += 1) {}
while (begin < slice.len and findScalar(T, values_to_strip, slice[begin]) != null) : (begin += 1) {}
return slice[begin..];
}
@ -1243,7 +1243,7 @@ pub const trimLeft = trimStart;
/// Remove a set of values from the end of a slice.
pub fn trimEnd(comptime T: type, slice: []const T, values_to_strip: []const T) []const T {
var end: usize = slice.len;
while (end > 0 and indexOfScalar(T, values_to_strip, slice[end - 1]) != null) : (end -= 1) {}
while (end > 0 and findScalar(T, values_to_strip, slice[end - 1]) != null) : (end -= 1) {}
return slice[0..end];
}
@ -1258,8 +1258,8 @@ pub const trimRight = trimEnd;
pub fn trim(comptime T: type, slice: []const T, values_to_strip: []const T) []const T {
var begin: usize = 0;
var end: usize = slice.len;
while (begin < end and indexOfScalar(T, values_to_strip, slice[begin]) != null) : (begin += 1) {}
while (end > begin and indexOfScalar(T, values_to_strip, slice[end - 1]) != null) : (end -= 1) {}
while (begin < end and findScalar(T, values_to_strip, slice[begin]) != null) : (begin += 1) {}
while (end > begin and findScalar(T, values_to_strip, slice[end - 1]) != null) : (end -= 1) {}
return slice[begin..end];
}
@ -3145,15 +3145,15 @@ test cutSuffix {
try testing.expectEqual(null, cutSuffix(u8, "foobar", "baz"));
}
/// Returns slice of `haystack` before and after `needle`, or `null` if not
/// found.
/// Returns slice of `haystack` before and after first occurrence of `needle`,
/// or `null` if not found.
///
/// See also:
/// * `cutScalar`
/// * `split`
/// * `tokenizeAny`
pub fn cut(comptime T: type, haystack: []const T, needle: []const T) ?struct { []const T, []const T } {
const index = indexOf(T, haystack, needle) orelse return null;
const index = find(T, haystack, needle) orelse return null;
return .{ haystack[0..index], haystack[index + needle.len ..] };
}
@ -3164,15 +3164,33 @@ test cut {
try testing.expectEqualStrings(" c", after);
}
/// Returns slice of `haystack` before and after `needle`, or `null` if not
/// found.
/// Returns slice of `haystack` before and after last occurrence of `needle`,
/// or `null` if not found.
///
/// See also:
/// * `cut`
/// * `cutScalarLast`
pub fn cutLast(comptime T: type, haystack: []const T, needle: []const T) ?struct { []const T, []const T } {
const index = findLast(T, haystack, needle) orelse return null;
return .{ haystack[0..index], haystack[index + needle.len ..] };
}
test cutLast {
try testing.expectEqual(null, cutLast(u8, "a b c", "B"));
const before, const after = cutLast(u8, "a be c be d", "be") orelse return error.TestFailed;
try testing.expectEqualStrings("a be c ", before);
try testing.expectEqualStrings(" d", after);
}
/// Returns slice of `haystack` before and after first occurrence `needle`, or
/// `null` if not found.
///
/// See also:
/// * `cut`
/// * `splitScalar`
/// * `tokenizeScalar`
pub fn cutScalar(comptime T: type, haystack: []const T, needle: T) ?struct { []const T, []const T } {
const index = indexOfScalar(T, haystack, needle) orelse return null;
const index = findScalar(T, haystack, needle) orelse return null;
return .{ haystack[0..index], haystack[index + 1 ..] };
}
@ -3183,6 +3201,25 @@ test cutScalar {
try testing.expectEqualStrings(" c", after);
}
/// Returns slice of `haystack` before and after last occurrence of `needle`,
/// or `null` if not found.
///
/// See also:
/// * `cut`
/// * `splitScalar`
/// * `tokenizeScalar`
pub fn cutScalarLast(comptime T: type, haystack: []const T, needle: T) ?struct { []const T, []const T } {
const index = findScalarLast(T, haystack, needle) orelse return null;
return .{ haystack[0..index], haystack[index + 1 ..] };
}
test cutScalarLast {
try testing.expectEqual(null, cutScalarLast(u8, "a b c", 'B'));
const before, const after = cutScalarLast(u8, "a b c b d", 'b') orelse return error.TestFailed;
try testing.expectEqualStrings("a b c ", before);
try testing.expectEqualStrings(" d", after);
}
/// Delimiter type for tokenization and splitting operations.
pub const DelimiterType = enum { sequence, any, scalar };

View File

@ -1057,9 +1057,8 @@ fn buildOutputType(
fatal("unexpected end-of-parameter mark: --", .{});
}
} else if (mem.eql(u8, arg, "--dep")) {
var it = mem.splitScalar(u8, args_iter.nextOrFatal(), '=');
const key = it.first();
const value = if (it.peek() != null) it.rest() else key;
const next_arg = args_iter.nextOrFatal();
const key, const value = mem.cutScalar(u8, next_arg, '=') orelse .{ next_arg, next_arg };
if (mem.eql(u8, key, "std") and !mem.eql(u8, value, "std")) {
fatal("unable to import as '{s}': conflicts with builtin module", .{
key,