gogen
is a general-purpose Go code generation toolkit. Like the Go compiler, It can perform type checking of expressions. For example, if you generate an expression like "Hello" + 1
, it will report the corresponding error.
Create a file named hellogen.go
, like below:
package main
import (
"go/token"
"go/types"
"os"
"github.com/goplus/gogen"
)
func main() {
pkg := gogen.NewPackage("", "main", nil)
fmt := pkg.Import("fmt")
v := pkg.NewParam(token.NoPos, "v", types.Typ[types.String]) // v string
pkg.NewFunc(nil, "main", nil, nil, false).BodyStart(pkg).
DefineVarStart(token.NoPos, "a", "b").Val("Hi").Val(3).EndInit(2). // a, b := "Hi", 3
NewVarStart(nil, "c").VarVal("b").EndInit(1). // var c = b
NewVar(gogen.TyEmptyInterface, "x", "y"). // var x, y interface{}
Val(fmt.Ref("Println")).
/**/ VarVal("a").VarVal("b").VarVal("c"). // fmt.Println(a, b, c)
/**/ Call(3).EndStmt().
NewClosure(gogen.NewTuple(v), nil, false).BodyStart(pkg).
/**/ Val(fmt.Ref("Println")).Val(v).Call(1).EndStmt(). // fmt.Println(v)
/**/ End().
Val("Hello").Call(1).EndStmt(). // func(v string) { ... } ("Hello")
End()
pkg.WriteTo(os.Stdout)
}
Try it like:
go mod init hello
go mod tidy
go run hellogen.go
This will dump Go source code to stdout
. The following is the output content:
package main
import "fmt"
func main() {
a, b := "Hi", 3
var c = b
var x, y interface{}
fmt.Println(a, b, c)
func(v string) {
fmt.Println(v)
}("Hello")
}