convert-case

Rust library for converting between string cases.

use convert_case::ccase;

assert_eq!(
    ccase!(camel, "My_Var_Name"),
    "myVarName",
);
assert_eq!(
    ccase!(snake, "IOStream"),
    "io_stream",
);
assert_eq!(
    ccase!(snake -> title, "2020-04-16_family_photo"),
    "2020-04-16 Family Photo",
);

convert-case is highly customizable. You can read the API documentation on docs.rs for a list of all features and read lots of examples.

Cases

This is list of cases that convert_case provides out of the box. You can always make your own custom case.

Case	Example
Snake	my_variable_name
Constant UpperSnake	MY_VARIABLE_NAME
Ada	My_Variable_Name
Kebab	my-variable-name
Cobol UpperKebab	MY-VARIABLE-NAME
Train	My-Variable-Name
Flat	myvariablename
UpperFlat	MYVARIABLENAME
Pascal UpperCamel	MyVariableName
Camel	myVariableName
Upper	MY VARIABLE NAME
Lower	my variable name
Title	My Variable Name
Sentence	My variable name

Additional utilities with convert_case_extras

Some cases and utilities that didn't feel appropriate in this library are made available in a distinct crate called convert_case_extras. This crate is a demonstration of what can be built on top of the convert_case API.

Command Line Utility ccase

The command line utility ccase was made to expose the tools of the convert_case library to the command line.

$ ccase -t title super_mario_64
Super Mario 64

$ ccase -f snake -t title 2020-04-15_my_cat
2020-04-16 My Cat

$ ccase -t camel "convert to camel"
convertToCamel

Links

	convert_case	convert_case_extras	ccase
Repository	github	github	github
Crate	crates.io	crates.io	crates.io
Documentation	docs.rs	docs.rs

Change Log

0.12.0: Optimizations

This release improves speed and memory efficiency. A couple techniques were used:

• Character case checks first check ascii before doing the more expensive grapheme checks (which require heap allocations).
• Delimiter only splits get a dedicated path in the split method.
• The case of characters is computed upfront in a bitmask before checking individual boundary conditions in split. Built-in boundaries get a custom implementation built on top of this bitmask.

Benchmark	Before	After	Improvement
snake_short ("hello_world")	412 ns	21.3 ns	−95%
lower_upper ("lowerUpperUpper")	1,631 ns	475 ns	−71%
acronym ("XMLRequest")	1,108 ns	418 ns	−62%
camel_set ("getTotalLength3D")	3,844 ns	643 ns	−83%
defaults_mixed (9 boundaries)	8,083 ns	1,500 ns	−81%
defaults_long_snake (265 chars)	52,281 ns	4,730 ns	−91%
unicode_cyrillic ("ПЕРСПЕКТИВА24")	8,334 ns	741 ns	−91%
Full pipeline from_to_all (4 words x 14 x 14)	1,230 µs	263 µs	−79%

See CHANGELOG.md for the full history.