README
¶
goimpl 
Forked from goimpl to add an improvement for my personal project, in which I needed to plugin this to go generate for linking the generated stub to their implementations.
A tool to generate stub implementation of an interface.
The output is printed to stdout, errors (if any) — to stderr.
Installation
go get github.com/anandmishra01/goimpl/cmd/goimpl
In a nutshell
goimpl io.ReadWriteCloser "*pkg.impl"
Would print
package pkg
type impl struct{}
func (i *impl) Close() (err error) {
return close()
}
func (i *impl) Read(u []uint8) (i1 int, err error) {
return read(u)
}
func (i *impl) Write(u []uint8) (i1 int, err error) {
return write(u)
}
Let's say you already have this (the Writer is almost http.ResponseWriter, but not quite):
package w12
import "net/http"
type Writer struct{}
func (w Writer) Write(float64) (error, *int) {
return nil, nil
}
func (Writer) Header() http.Header {
return nil
}
Running
goimpl -existing http.ResponseWriter "w12.Writer"
Gives
package w12
type Writer struct{}
// inputs[0]: had `float64` want `[]uint8`; outputs[0]: had `error` want `int`; outputs[1]: had `*int` want `error`
func (w Writer) Write(u []uint8) (i int, err error) {
return
}
func (w Writer) WriteHeader(i int) {
return
}
Here only the missing methods and the methods with wrong signature are generates.
Usage
Usage: goimpl [flags] [import1] [import2...] package.interfaceTypeName [(*|&)][package2.]typeName
This would generate empty implementation of the interfaceTypeName.
-existing=false: Would trigger generation of missing method for the existing type(struct). Note, that if you want to use a pointer receiver prefix the type with '&'.
-goimports=true: Run goimports on the generated code. The generated code might not compile if this is not set.
-named=true: Generate named return values. The genrated code might not compile if this is not set.
Alternative(s)
- impl is parsing AST, goimpl is using reflection.
- impl is much faster and has better error reporting.
- goimpl generates complete code that (usually) compiles (package/ imports).
- goimpl can generate a minimum update for the exising implementation.
- goimpl can work with ambiguous package names.
Documentation
¶
Overview ¶
A tool to generate stub implementation of an interface.
Index ¶
- func Generate(opts *GenOpts, out io.Writer) error
- type Arg
- type GenOpts
- func (opts *GenOpts) Clean(s string) string
- func (GenOpts) First(s string) string
- func (opts *GenOpts) GetName(t reflect.Type) string
- func (opts *GenOpts) Method(recName string, ft reflect.Method) Method
- func (opts *GenOpts) Methods(it reflect.Type) []Method
- func (opts *GenOpts) Short(t reflect.Type, cur map[string]struct{}) string
- type Method
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
Types ¶
type Arg ¶
type Arg struct {
reflect.Type
ArgName string // Name for a variable for this arg.
Sep string // Separator - empty if it the last arg in a list, comma otherwise.
}
Arg describes an argument of a method: either in or out.
type GenOpts ¶
type GenOpts struct {
PkgName string // target package.
ImplName string // type (struct) that would implement the interface.
Inter reflect.Type // Interface to implement.
Existing interface{} // Existing type that we want to implement the interface.
NoNamedReturnValues bool // Do not generate named return values. The generated code might not compile if this is set.
MethodBlacklist map[string]struct{} // Would not generate the code for those methods.
Comments map[string]string // Add comments to those methods in generated code.
NoGoImports bool // No goimports if set. Faster. The generated code might not compile.
Extra []string // Extra imports.
}
GenOpts specifies code generation options.
func (*GenOpts) Method ¶
Method populates the Method struct. recName is a name of the receiver in the generated code.
Source Files
Directories
Click to show internal directories.
Click to hide internal directories.