README.md

Aspartame

A tool that makes some go things (currently only "enums") slightly less annoying to me. Probably not idiomatic; check TODO for potential changes / ways to contribute.

Usage

aspartame may be run via command line:

go get github.com/falun/aspartame
go install github.com/falun/aspartame
./bin/aspartame \
   -name Foo \
   -enumType FooEnumType \
   -source ./src/github.com/falun/aspartame/testdata/

or as a go:generate tool:

package main

//go:generate aspartame -name Foo -enumType FooEnumType -source $GOFILE
type FooEnumType int

const (
	bar FooEnumType = iota
	baz
	quix
	quux
)

Note that -source $GOFILE is optional but prevents the tool from guessing the wrong file since a generated file will be a potential match if we're given only the type name to target.

The tool checks for two things when examining a const block declaration and determining if it meets the requirement for sweetening.

1. The values are not exported. The reasoning is that we want to limit confusion about what is available in the package namespace;
2. The enum value names do not begin with _;
3. The const block declares only values of the same type.

Additionally if you want to change how an enum is represented as a string value you can add a render directive as a comment to the declaration. An example of that would be:

const (
	bar FooEnumType = iota
	baz
	quix // render: QuiX
	quux
)

Now when converting Foo.Quix to or from a string "QuiX" is the expected name. The const as accessed in code will just be a capitalized version of the initial definition and the rendered value does not come into play. The play example below makes use of the render tag.

Results

The generated code will be produced in the same package and currently provides the following convenience methods:

• Enum value access via $EnumName.$ValueName (in our example above Foo.Bar, Foo.Quix, etc.)
• $EnumName.Values()—produces an array of all values
• $EnumName.String()—readable output
• $EnumName.ByValue(int)—given an int find the corresponding enum value
• $EnumName.ByName(string)—given an enum name produce the corresponding value

Example

See this play link

Limitations

I'm sure there are a lot but thus far it's good enough for my uses. File an issue of something doesn't work the way you expect.