tada-team/bang

go:generate from .yml

Bang

Sugar for go generate.

Reads yml data from .go source file and render template with variables.

How to use it

1. Install:

go install github.com/tada-team/bang

2. Write line //go:generate bang $GOFILE:$GOLINE, and //-commented yaml content below:

package mypackage

//go:generate bang $GOFILE:$GOLINE
//  
//  ...yaml...
//

Yaml format is:

template: <go template contents>
vars: <variables for template>
dest: <filename for saving rendered template>

3. run go generate

Template will be rendered and code wil be formatted.

Example

package main

//go:generate bang $GOFILE:$GOLINE
// dest: main_generated.go
// vars:
//   package: main
//   types:
//    - int
//    - float64
// template: >
//   package {{ .package }}
//
//   {{ range $type := .types }}
//       func {{ $type }}Sum(a, b {{ $type }}) {{ $type }} {
//           return a + b
//       }
//   {{ end }}
//

Result (main_generated.go):

// Code generated by Bang.go DO NOT EDIT.

package main

func intSum(a, b int) int {
	return a + b
}

func float64Sum(a, b float64) float64 {
	return a + b
}

Optional command line flags

• -dest argument overrides dest key in yaml
• -template argument takes template from given template file
• -vars argument takes vars from given yaml file
• -verbose argument adds more output

Example:

package main

//go:generate bang -verbose -dest=main_generated.go -template=main.tpl $GOFILE:$GOLINE

vars.tpl:

package: main
types:
 - int
 - float64

main.tpl:

package {{ .package }}

{{ range $type := .types }}
  func {{ $type }}Sum(a, b {{ $type }}) {{ $type }} {
    return a + b
  }
{{ end }}