fmgen

Go Factory Method Generator

A Go factory method generator. Parses all packages to find all struct signatures. Then generates a fm_gen.go file for each package.

Source

// Sample demo struct
type Sample struct {
    ID          int64 `fmgen:"-"`
    Name        string
    Age         int64 `fmgen:"optional"`
    LastUpdated time.Time
}

Output

// NewSample generated factory method for Sample
func NewSample(Name string, LastUpdated time.Time, Age *int64) *Sample {
    result := &Sample{
        Name:        Name,
        LastUpdated: LastUpdated,
    }
    if Age != nil {
        result.Age = *Age
    }
    return result
}

Usage Flags

-d will specify the directory to parse (defaults to ./)

-r recursively process directories (defaults to true)

-f overrides -d, will process a single file instead

-s comma separated list of structs to include. all others will be ignored

-v verbose mode, will include additional logging

Example Usage

This will search the directory recursively and only process Struct1

fmgen -d ./pkg -s Struct1

Options

Adding fmgen:- to a struct comment will exclude that struct from generation

// Sample demo struct, fmgen:-
type Sample struct {
    ...
}

Adding fmgen:- to a struct field will omit that field

type Sample struct {
    ID int64 `fmgen:"-"`
    ...
}

Adding fmgen:optional to a struct field will allow a nil to be passed in. A nil will be skipped when creating the struct

type Sample struct {
    ID int64 `fmgen:"optional"`
    ...
}