Convert Case

Converts to and from various cases.

Rust Library convert_case

Convert case is written in Rust and is ready to be used inline with your rust code as a library.

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",
);

You can read the API documentation on docs.rs for a list of all features and read lots of examples.

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

Cases

This is list of cases that convert_case supports. Some cases are simply aliases of others. The "Random" and "PseudoRandom" cases are provided in the convert_case library with the "random" feature.

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
Alternating	mY vArIaBlE nAmE
Toggle	mY vARIABLE nAME
Random	MY vaRiabLe nAME
PseudoRandom	mY VaRiAblE nAMe

Change Log

0.9.0: Back to enums, but keep the customization

This release is trying to finalize the API for a 1.0.0 release. In hindsight, making Pattern a function and Boundary a struct were poor decisions. While trying to add customized behavior, I made it harder to use. Luckily, by following the convention that was done with Case in 0.8.0, which was providing a struct-variant Case::Custom, I can keep the new customization options while reverting back to the enum pattern the library has had since the beginning.

If you are updating from before 0.7.0, I don't think any changes are necessary. If you're coming from 0.7.0 or higher,

• Change boundaries from constants to enum variants: Boundary::UPPER_SNAKE into Boundary::UpperSnake
• Change patterns from functions to enum variants on Pattern: pattern::lowercase into Pattern::Lowercase

Most excitingly, I've introduced a brand new way to use the crate for 99% of use cases, which is the default behavior out of the box to just convert a string to a case, with no modifications to behavior. Instead of

use convert_case::{Case, Casing};
"MyVarName".to_case(Case::Snake);
"my-var name".from_case(Case::Title).to_case(Case::Snake);

You can use the ccase! macro:

use convert_case::ccase;
ccase!(snake, "MyVarName");
ccase!(title -> snake, "my-var name");

This means only one import and its invocation is brief and easy to read. This is now the first thing you see when viewing the docs, which themselves have gotten a huge overhaul and many improvements in this version.

New features:

• ccase! macro that performs case conversion on a string without needing to import Case or Casing. It has two forms:
  • ccase!(snake, "string") is equivalent to "string".to_case(Case::Snake)
  • ccase!(kebab -> snake, "string") is equivalent to "string".from_case(Case::Kebab).to_case(Case::Snake)
• While not intended to be used directly, the new case! macro returns a Case variant from the snake case version of the variant. For instance, case!(snake) is substituted for Case::Snake and case!(upper_flat) for Case::UpperFlat.

Other breaking changes:

• Leading, trailing, and duplicate delimiters are no longer removed and are returned as is.
• Boundary is reverted back to being an enum, but with a Custom variant that gives all the same flexibility that Boundary had as a struct. This aligns with the Case::Custom pattern.
  • Boundary.match will return true if a set of graphemes matches the boundary condition
  • Boundary methods for start and len describe how enum variants consume letters when matched
• Pattern is reverted back to being an enum, but with a Custom variant that allowed you to pass your own fn (&[&str]) -> Vec<String> as input.
  • Pattern.mutate will perform the associated mutation function
• Converter.with_boundaries has been renamed to Converter.set_boundaries.
• Removed Converter.remove_delim and Converter.remove_pattern. You can use set_delim("") and set_pattern(Pattern::Noop) instead.
• ToString is no longer a required trait for using is_case
• word_pattern module has been removed

0.8.0: Pattern Overhaul, Custom Case

Pattern is no longer an enum. It is now a type alias for fn(&[&str]) -> Vec<String>. The variants of Pattern can now be referenced as functions inside the pattern module. For upgrading this means changing Pattern::Lowercase to pattern::lowercase, and calling the function directly instead of invoking the mutate method on the enum.

Inside the pattern module is also the type alias Pattern itself.

Other breaking changes:

• Add Case::Ada (capital pattern with underscore delimiter.)
• Add Case::Custom variant. It is a struct variant that takes three parameters:
  • pattern with type Pattern
  • delim with type &static str, and
  • boundaries with type &'static [Boundary].
• Because of the new pattern::noop function, Converter attribute pattern is now of type Pattern and not Option<Pattern>
• Case::deterministic_cases, Case::all_cases, and Case::random_cases now return static arrays instead of vecs

Other changes:

• Added Case::split, Case::mutate, and Case::join which expose operations related to the boundaries, pattern, and delimiter of a case
• Is now no_std compatible

0.7.1

• Removed debug print statement.

0.7.0: Custom Boundaries

Boundary is no longer an enum. It now is a struct, and each enum variant cooresponds to an associated constant. For upgrading this just means changing Boundary::LowerUpper to just Boundary::LOWER_UPPER.

The benefit of this is that you can make your boundary conditions now, by instantiating the Boundary struct, or using Boundary::from_delim(). Now you can split on newlines, periods, double-colons, emojis, or a more complex case like a symbol followed by a digit. You also define which characters, if any, are removed during segmentation, and where the split happens.

Changes from this feature:

• Previous Boundary::PascalName enum variants now much refered to as Boundary::CONSTANT_NAME constants.
• All functions that returned groups of boundaries (such as Boundary::defaults(), Boundary::digit_letter(), etc) now are const and return fixed-sized arrays [Boundary; N], not Vec<Boundary>.
• Boundary::all() was removed, since there's no longer a sense of "all" boundaries, since you can create your own.
• Boundary::list_from() has been renamed to Boundary::defaults_from() and no longer outputs Boundary::UPPER_LOWER, since this function now only checks default boundaries.
• Create custom delimiter boundaries using Boundary::from_delim().

Other breaking changes:

• Rename Case::ScreamingSnake to Case::Constant.
• Add Case::Sentence (sentence pattern and space delimiter.)
• Casing trait implemented for Arc<str> and Rc<str> again.

Other changes:

• Remove most imports from doc comments.
• Remove loop over str::chars in favor of graphemes from unicode-segmentation.