4.2 String Views

For performance reasons, most functions in serd that take a string take a SerdStringView, rather than a bare pointer. This forces code to be explicit about string measurement, which discourages common patterns of repeated measurement of the same string. For convenience, several macros are provided for constructing string views:

SERD_EMPTY_STRING

Constructs a view of an empty string, for example:

SerdStringView empty = SERD_EMPTY_STRING();

SERD_STRING

Constructs a view of an entire string or string literal, for example:

SerdStringView hello = SERD_STRING("hello");

or:

SerdStringView view = SERD_STRING(string_pointer);

This macro calls strlen to measure the string. Modern compilers will optimise this away if the parameter is a string literal.

SERD_SUBSTRING

Constructs a view of a slice of a string with an explicit length, for example:

SerdStringView slice = SERD_SUBSTRING(string_pointer, 4);

This macro can also be used to create a view of a pre-measured string. If the length a dynamic string is already known, it is faster to use this than SERD_STRING.

These macros can be used inline when passing parameters, but if the same dynamic string is used several times, it is better to make a string view variable to avoid redundant measurement.