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For the complete Mojo documentation index, see llms.txt. Markdown versions of all pages are available by appending .md to any URL (e.g. /docs/manual/basics.md).

string_span

Implements the StringSpan type and related utilities for efficient string operations.

comptime values​

ImmStringSlice​

comptime ImmStringSlice[origin: ImmOrigin] = ImmStringSpan

Provides a compatibility alias for ImmStringSpan.

Parameters​

ImmStringSpan​

comptime ImmStringSpan[origin: ImmOrigin] = StringSpan[origin]

Provides read-only access to the string data it views.

Parameters​

  • ​origin (ImmOrigin): The origin of the string data.

MutStringSlice​

comptime MutStringSlice[origin: MutOrigin] = MutStringSpan

Provides a compatibility alias for MutStringSpan.

Parameters​

MutStringSpan​

comptime MutStringSpan[origin: MutOrigin] = StringSpan[origin]

Provides mutable access to the string data it views.

Parameters​

  • ​origin (MutOrigin): The origin of the string data.

StaticString​

comptime StaticString = StringSpan[ImmStaticOrigin]

An immutable static string span.

This is a type of StringSpan that's immutable and statically allocated. You might use this for situations that could also be done with a String type, but when you want to optimize memory usage with zero heap allocations.

The key difference from StringSpan is that a StaticString is guaranteed to point to data (string literals, constants) that will never be deallocated (a regular StringSpan may point to any string data that might be freed). This makes StaticString safe to store long-term without lifetime concerns.

Although you can reassign a StaticString-typed variable with a new value, you can't modify the underlying data of a StaticString after it's created the way you can with a String, such as using += to append to it.

Because this is still a StringSpan type, you can do all the same things with it, such as format a string:

var format_string = StaticString("{}: {}")
print(format_string.format("bats", 6))     # => bats: 6

StringSlice​

comptime StringSlice = StringSpan[_]

Provides a compatibility alias for StringSpan.

Structs​

Functions​

  • ​get_static_string: Form a StaticString from compile-time StringSpan values. This guarantees that the returned string is compile-time constant in static memory. It also guarantees that there is a 'nul' zero byte at the end, which is not included in the returned range.
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