:sig
function substr(value : string, start : s32) string
function substr(value : string, start : s64) string
function substr(value : string, start : s32, length : s32) string
function substr(value : string, start : s64, length : s64) string

:returns
Extracted text.

:content
Use `substr` to get part of a string. A negative start or length counts from the end.

:example capy render
print(substr("documentation", 0, 3), "\n")

:see-group
strings
