jen

package
v0.17.0 Latest Latest
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 Go to latest Published: Jan 10, 2018 License: MIT Imports: 9 Imported by: 0

Documentation

Overview

Package jen is a code generator for Go

Index

Examples

Constants

This section is empty.

Variables

This section is empty.

Functions

This section is empty.

Types

type Code 

type Code interface {
	// contains filtered or unexported methods
}

Code represents an item of code that can be rendered.

type Dict 

type Dict map[Code]Code

Dict renders as key/value pairs. Use with Values for map or composite literals.

Example 
c := Id("a").Op(":=").Map(String()).String().Values(Dict{
	Lit("a"): Lit("b"),
	Lit("c"): Lit("d"),
})
fmt.Printf("%#v", c)

Output:

a := map[string]string{
	"a": "b",
	"c": "d",
}
Example (Nil) 
c := Id("a").Op(":=").Map(String()).String().Values()
fmt.Printf("%#v", c)

Output:

a := map[string]string{}

func DictFunc 

func DictFunc(f func(Dict)) Dict

DictFunc executes a func(Dict) to generate the value. Use with Values for map or composite literals.

Example 
c := Id("a").Op(":=").Map(String()).String().Values(DictFunc(func(d Dict) {
	d[Lit("a")] = Lit("b")
	d[Lit("c")] = Lit("d")
}))
fmt.Printf("%#v", c)

Output:

a := map[string]string{
	"a": "b",
	"c": "d",
}

type File 

type File struct {
	*Group

	// If you're worried about package aliases conflicting with local variable
	// names, you can set a prefix here. Package foo becomes {prefix}_foo.
	PackagePrefix string
	// contains filtered or unexported fields
}

File represents a single source file. Package imports are managed automaticaly by File.

func NewFile 

func NewFile(packageName string) *File

NewFile Creates a new file, with the specified package name.

Example 
f := NewFile("main")
f.Func().Id("main").Params().Block(
	Qual("fmt", "Println").Call(Lit("Hello, world")),
)
fmt.Printf("%#v", f)

Output:

package main

import fmt "fmt"

func main() {
	fmt.Println("Hello, world")
}

func NewFilePath 

func NewFilePath(packagePath string) *File

NewFilePath creates a new file while specifying the package path - the package name is inferred from the path.

Example 
f := NewFilePath("a.b/c")
f.Func().Id("init").Params().Block(
	Qual("a.b/c", "Foo").Call().Comment("Local package - alias is omitted."),
	Qual("d.e/f", "Bar").Call().Comment("Import is automatically added."),
	Qual("g.h/f", "Baz").Call().Comment("Colliding package name is automatically renamed."),
)
fmt.Printf("%#v", f)

Output:

package c

import (
	f "d.e/f"
	f1 "g.h/f"
)

func init() {
	Foo()    // Local package - alias is omitted.
	f.Bar()  // Import is automatically added.
	f1.Baz() // Colliding package name is automatically renamed.
}

func NewFilePathName 

func NewFilePathName(packagePath, packageName string) *File

NewFilePathName creates a new file with the specified package path and name.

Example 
f := NewFilePathName("a.b/c", "main")
f.Func().Id("main").Params().Block(
	Qual("a.b/c", "Foo").Call(),
)
fmt.Printf("%#v", f)

Output:

package main

func main() {
	Foo()
}

func (*File) Anon 

func (f *File) Anon(paths ...string)

Anon adds an anonymous import:

Example 
f := NewFile("c")
f.Anon("a")
f.Func().Id("init").Params().Block()
fmt.Printf("%#v", f)

Output:

package c

import _ "a"

func init() {}

func (*File) CgoPreamble added in v0.17.0 

func (f *File) CgoPreamble(comment string)

CgoPreamble adds a cgo preamble comment that is rendered directly before the "C" pseudo-package import.

Example 
f := NewFile("a")
f.CgoPreamble(`#include <stdio.h>
#include <stdlib.h>

void myprint(char* s) {
	printf("%s\n", s);
}
`)
f.Func().Id("init").Params().Block(
	Id("cs").Op(":=").Qual("C", "CString").Call(Lit("Hello from stdio\n")),
	Qual("C", "myprint").Call(Id("cs")),
	Qual("C", "free").Call(Qual("unsafe", "Pointer").Parens(Id("cs"))),
)
fmt.Printf("%#v", f)

Output:

package a

import unsafe "unsafe"

/*
#include <stdio.h>
#include <stdlib.h>

void myprint(char* s) {
	printf("%s\n", s);
}
*/
import "C"

func init() {
	cs := C.CString("Hello from stdio\n")
	C.myprint(cs)
	C.free(unsafe.Pointer(cs))
}
Example (Anon) 
f := NewFile("a")
f.CgoPreamble(`#include <stdio.h>`)
f.Func().Id("init").Params().Block(
	Qual("foo.bar/a", "A"),
	Qual("foo.bar/b", "B"),
)
fmt.Printf("%#v", f)

Output:

package a

import (
	a "foo.bar/a"
	b "foo.bar/b"
)

// #include <stdio.h>
import "C"

func init() {
	a.A
	b.B
}
Example (No_preamble) 
f := NewFile("a")
f.Func().Id("init").Params().Block(
	Qual("C", "Foo").Call(),
	Qual("fmt", "Print").Call(),
)
fmt.Printf("%#v", f)

Output:

package a

import (
	"C"
	fmt "fmt"
)

func init() {
	C.Foo()
	fmt.Print()
}
Example (No_preamble_anon) 
f := NewFile("a")
f.Anon("C")
f.Func().Id("init").Params().Block(
	Qual("fmt", "Print").Call(),
)
fmt.Printf("%#v", f)

Output:

package a

import (
	"C"
	fmt "fmt"
)

func init() {
	fmt.Print()
}
Example (No_preamble_single) 
f := NewFile("a")
f.Func().Id("init").Params().Block(
	Qual("C", "Foo").Call(),
)
fmt.Printf("%#v", f)

Output:

package a

import "C"

func init() {
	C.Foo()
}
Example (No_preamble_single_anon) 
f := NewFile("a")
f.Anon("C")
f.Func().Id("init").Params().Block()
fmt.Printf("%#v", f)

Output:

package a

import "C"

func init() {}

func (*File) GoString 

func (f *File) GoString() string

GoString renders the File for testing. Any error will cause a panic.

func (*File) HeaderComment added in v0.15.0 

func (f *File) HeaderComment(comment string)

HeaderComment adds a comment to the top of the file, above any package comments. A blank line is rendered below the header comments, ensuring header comments are not included in the package doc.

func (*File) PackageComment 

func (f *File) PackageComment(comment string)

PackageComment adds a comment to the top of the file, above the package keyword.

func (*File) Render 

func (f *File) Render(w io.Writer) error

Render renders the file to the provided writer.

Example 
f := NewFile("a")
f.Func().Id("main").Params().Block()
buf := &bytes.Buffer{}
err := f.Render(buf)
if err != nil {
	fmt.Println(err.Error())
} else {
	fmt.Println(buf.String())
}

Output:

package a

func main() {}

func (*File) Save 

func (f *File) Save(filename string) error

Save renders the file and saves to the filename provided.

type Group 

type Group struct {
	// contains filtered or unexported fields
}

Group represents a list of Code items, separated by tokens with an optional open and close token.

func (*Group) Add 

func (g *Group) Add(code ...Code) *Statement

Add appends the provided items to the statement.

func (*Group) Append 

func (g *Group) Append(args ...Code) *Statement

Append renders the append built-in function.

func (*Group) AppendFunc added in v0.9.1 

func (g *Group) AppendFunc(f func(*Group)) *Statement

AppendFunc renders the append built-in function.

func (*Group) Assert 

func (g *Group) Assert(typ Code) *Statement

Assert renders a period followed by a single item enclosed by parenthesis. Use for type assertions.

func (*Group) Block 

func (g *Group) Block(statements ...Code) *Statement

Block renders a statement list enclosed by curly braces. Use for code blocks. A special case applies when used directly after Case or Default, where the braces are omitted. This allows use in switch and select statements.

func (*Group) BlockFunc 

func (g *Group) BlockFunc(f func(*Group)) *Statement

BlockFunc renders a statement list enclosed by curly braces. Use for code blocks. A special case applies when used directly after Case or Default, where the braces are omitted. This allows use in switch and select statements.

func (*Group) Bool 

func (g *Group) Bool() *Statement

Bool renders the bool identifier.

func (*Group) Break 

func (g *Group) Break() *Statement

Break renders the break keyword.

func (*Group) Byte 

func (g *Group) Byte() *Statement

Byte renders the byte identifier.

func (*Group) Call 

func (g *Group) Call(params ...Code) *Statement

Call renders a comma separated list enclosed by parenthesis. Use for function calls.

func (*Group) CallFunc 

func (g *Group) CallFunc(f func(*Group)) *Statement

CallFunc renders a comma separated list enclosed by parenthesis. Use for function calls.

func (*Group) Cap 

func (g *Group) Cap(v Code) *Statement

Cap renders the cap built-in function.

func (*Group) Case 

func (g *Group) Case(cases ...Code) *Statement

Case renders the keyword followed by a comma separated list.

func (*Group) CaseFunc 

func (g *Group) CaseFunc(f func(*Group)) *Statement

CaseFunc renders the keyword followed by a comma separated list.

func (*Group) Chan 

func (g *Group) Chan() *Statement

Chan renders the chan keyword.

func (*Group) Close 

func (g *Group) Close(c Code) *Statement

Close renders the close built-in function.

func (*Group) Comment 

func (g *Group) Comment(str string) *Statement

Comment adds a comment. If the provided string contains a newline, the comment is formatted in multiline style. If the comment string starts with "//" or "/*", the automatic formatting is disabled and the string is rendered directly.

func (*Group) Commentf 

func (g *Group) Commentf(format string, a ...interface{}) *Statement

Commentf adds a comment, using a format string and a list of parameters. If the provided string contains a newline, the comment is formatted in multiline style. If the comment string starts with "//" or "/*", the automatic formatting is disabled and the string is rendered directly.

func (*Group) Complex 

func (g *Group) Complex(r Code, i Code) *Statement

Complex renders the complex built-in function.

func (*Group) Complex128 

func (g *Group) Complex128() *Statement

Complex128 renders the complex128 identifier.

func (*Group) Complex64 

func (g *Group) Complex64() *Statement

Complex64 renders the complex64 identifier.

func (*Group) Const 

func (g *Group) Const() *Statement

Const renders the const keyword.

func (*Group) Continue 

func (g *Group) Continue() *Statement

Continue renders the continue keyword.

func (*Group) Copy 

func (g *Group) Copy(dst Code, src Code) *Statement

Copy renders the copy built-in function.

func (*Group) Default 

func (g *Group) Default() *Statement

Default renders the default keyword.

func (*Group) Defer 

func (g *Group) Defer() *Statement

Defer renders the defer keyword.

func (*Group) Defs 

func (g *Group) Defs(definitions ...Code) *Statement

Defs renders a statement list enclosed in parenthesis. Use for definition lists.

func (*Group) DefsFunc 

func (g *Group) DefsFunc(f func(*Group)) *Statement

DefsFunc renders a statement list enclosed in parenthesis. Use for definition lists.

func (*Group) Delete 

func (g *Group) Delete(m Code, key Code) *Statement

Delete renders the delete built-in function.

func (*Group) Do 

func (g *Group) Do(f func(*Statement)) *Statement

Do calls the provided function with the statement as a parameter. Use for embedding logic.

func (*Group) Dot added in v0.11.0 

func (g *Group) Dot(name string) *Statement

Dot renders a period followed by an identifier. Use for fields and selectors.

func (*Group) Else 

func (g *Group) Else() *Statement

Else renders the else keyword.

func (*Group) Empty 

func (g *Group) Empty() *Statement

Empty adds an empty item. Empty items render nothing but are followed by a separator in lists.

func (*Group) Err 

func (g *Group) Err() *Statement

Err renders the err identifier.

func (*Group) Error 

func (g *Group) Error() *Statement

Error renders the error identifier.

func (*Group) Fallthrough 

func (g *Group) Fallthrough() *Statement

Fallthrough renders the fallthrough keyword.

func (*Group) False 

func (g *Group) False() *Statement

False renders the false identifier.

func (*Group) Float32 

func (g *Group) Float32() *Statement

Float32 renders the float32 identifier.

func (*Group) Float64 

func (g *Group) Float64() *Statement

Float64 renders the float64 identifier.

func (*Group) For 

func (g *Group) For(conditions ...Code) *Statement

For renders the keyword followed by a semicolon separated list.

func (*Group) ForFunc 

func (g *Group) ForFunc(f func(*Group)) *Statement

ForFunc renders the keyword followed by a semicolon separated list.

func (*Group) Func 

func (g *Group) Func() *Statement

Func renders the func keyword.

func (*Group) Go 

func (g *Group) Go() *Statement

Go renders the go keyword.

func (*Group) GoString 

func (g *Group) GoString() string

GoString renders the Group for testing. Any error will cause a panic.

func (*Group) Goto 

func (g *Group) Goto() *Statement

Goto renders the goto keyword.

func (*Group) Id 

func (g *Group) Id(name string) *Statement

Id renders an identifier.

func (*Group) If 

func (g *Group) If(conditions ...Code) *Statement

If renders the keyword followed by a semicolon separated list.

func (*Group) IfFunc 

func (g *Group) IfFunc(f func(*Group)) *Statement

IfFunc renders the keyword followed by a semicolon separated list.

func (*Group) Imag 

func (g *Group) Imag(c Code) *Statement

Imag renders the imag built-in function.

func (*Group) Index 

func (g *Group) Index(items ...Code) *Statement

Index renders a colon separated list enclosed by square brackets. Use for array / slice indexes and definitions.

func (*Group) IndexFunc 

func (g *Group) IndexFunc(f func(*Group)) *Statement

IndexFunc renders a colon separated list enclosed by square brackets. Use for array / slice indexes and definitions.

func (*Group) Int 

func (g *Group) Int() *Statement

Int renders the int identifier.

func (*Group) Int16 

func (g *Group) Int16() *Statement

Int16 renders the int16 identifier.

func (*Group) Int32 

func (g *Group) Int32() *Statement

Int32 renders the int32 identifier.

func (*Group) Int64 

func (g *Group) Int64() *Statement

Int64 renders the int64 identifier.

func (*Group) Int8 

func (g *Group) Int8() *Statement

Int8 renders the int8 identifier.

func (*Group) Interface 

func (g *Group) Interface(methods ...Code) *Statement

Interface renders the keyword followed by a method list enclosed by curly braces.

func (*Group) InterfaceFunc 

func (g *Group) InterfaceFunc(f func(*Group)) *Statement

InterfaceFunc renders the keyword followed by a method list enclosed by curly braces.

func (*Group) Iota 

func (g *Group) Iota() *Statement

Iota renders the iota identifier.

func (*Group) Len 

func (g *Group) Len(v Code) *Statement

Len renders the len built-in function.

func (*Group) Line 

func (g *Group) Line() *Statement

Line inserts a blank line.

func (*Group) List 

func (g *Group) List(items ...Code) *Statement

List renders a comma separated list. Use for multiple return functions.

func (*Group) ListFunc 

func (g *Group) ListFunc(f func(*Group)) *Statement

ListFunc renders a comma separated list. Use for multiple return functions.

func (*Group) Lit 

func (g *Group) Lit(v interface{}) *Statement

Lit renders a literal, using the format provided by the fmt package %#v verb.

func (*Group) LitByte added in v0.13.0 

func (g *Group) LitByte(v byte) *Statement

LitByte renders a byte literal.

func (*Group) LitByteFunc added in v0.13.0 

func (g *Group) LitByteFunc(f func() byte) *Statement

LitByteFunc renders a byte literal. LitByteFunc generates the value to render by executing the provided function.

func (*Group) LitFunc 

func (g *Group) LitFunc(f func() interface{}) *Statement

LitFunc renders a literal, using the format provided by the fmt package %#v verb. LitFunc generates the value to render by executing the provided function.

func (*Group) LitRune added in v0.13.0 

func (g *Group) LitRune(v rune) *Statement

LitRune renders a rune literal.

func (*Group) LitRuneFunc added in v0.13.0 

func (g *Group) LitRuneFunc(f func() rune) *Statement

LitRuneFunc renders a rune literal. LitRuneFunc generates the value to render by executing the provided function.

func (*Group) Make 

func (g *Group) Make(args ...Code) *Statement

Make renders the make built-in function. The final parameter of the make function is optional, so it is represented by a variadic parameter list.

func (*Group) Map 

func (g *Group) Map(typ Code) *Statement

Map renders the keyword followed by a single item enclosed by square brackets. Use for map definitions.

func (*Group) New 

func (g *Group) New(typ Code) *Statement

New renders the new built-in function.

func (*Group) Nil 

func (g *Group) Nil() *Statement

Nil renders the nil identifier.

func (*Group) Null 

func (g *Group) Null() *Statement

Null adds a null item. Null items render nothing and are not followed by a separator in lists.

func (*Group) Op 

func (g *Group) Op(op string) *Statement

Op renders the provided operator / token.

func (*Group) Panic 

func (g *Group) Panic(v Code) *Statement

Panic renders the panic built-in function.

func (*Group) Params 

func (g *Group) Params(params ...Code) *Statement

Params renders a comma separated list enclosed by parenthesis. Use for function parameters and method receivers.

func (*Group) ParamsFunc 

func (g *Group) ParamsFunc(f func(*Group)) *Statement

ParamsFunc renders a comma separated list enclosed by parenthesis. Use for function parameters and method receivers.

func (*Group) Parens 

func (g *Group) Parens(item Code) *Statement

Parens renders a single item in parenthesis. Use for type conversion or to specify evaluation order.

func (*Group) Print 

func (g *Group) Print(args ...Code) *Statement

Print renders the print built-in function.

func (*Group) PrintFunc added in v0.9.1 

func (g *Group) PrintFunc(f func(*Group)) *Statement

PrintFunc renders the print built-in function.

func (*Group) Println 

func (g *Group) Println(args ...Code) *Statement

Println renders the println built-in function.

func (*Group) PrintlnFunc added in v0.9.1 

func (g *Group) PrintlnFunc(f func(*Group)) *Statement

PrintlnFunc renders the println built-in function.

func (*Group) Qual 

func (g *Group) Qual(path, name string) *Statement

Qual renders a qualified identifier. Imports are automatically added when used with a File. If the path matches the local path, the package name is omitted. If package names conflict they are automatically renamed.

func (*Group) Range 

func (g *Group) Range() *Statement

Range renders the range keyword.

func (*Group) Real 

func (g *Group) Real(c Code) *Statement

Real renders the real built-in function.

func (*Group) Recover 

func (g *Group) Recover() *Statement

Recover renders the recover built-in function.

func (*Group) Render added in v0.15.0 

func (g *Group) Render(writer io.Writer) error

Render renders the Group to the provided writer.

func (*Group) Return 

func (g *Group) Return(results ...Code) *Statement

Return renders the keyword followed by a comma separated list.

func (*Group) ReturnFunc 

func (g *Group) ReturnFunc(f func(*Group)) *Statement

ReturnFunc renders the keyword followed by a comma separated list.

func (*Group) Rune 

func (g *Group) Rune() *Statement

Rune renders the rune identifier.

func (*Group) Select 

func (g *Group) Select() *Statement

Select renders the select keyword.

func (*Group) String 

func (g *Group) String() *Statement

String renders the string identifier.

func (*Group) Struct 

func (g *Group) Struct(fields ...Code) *Statement

Struct renders the keyword followed by a field list enclosed by curly braces.

func (*Group) StructFunc added in v0.9.3 

func (g *Group) StructFunc(f func(*Group)) *Statement

StructFunc renders the keyword followed by a field list enclosed by curly braces.

func (*Group) Switch 

func (g *Group) Switch(conditions ...Code) *Statement

Switch renders the keyword followed by a semicolon separated list.

func (*Group) SwitchFunc 

func (g *Group) SwitchFunc(f func(*Group)) *Statement

SwitchFunc renders the keyword followed by a semicolon separated list.

func (*Group) Tag 

func (g *Group) Tag(items map[string]string) *Statement

Tag renders a struct tag

func (*Group) True 

func (g *Group) True() *Statement

True renders the true identifier.

func (*Group) Type 

func (g *Group) Type() *Statement

Type renders the type keyword.

func (*Group) Uint 

func (g *Group) Uint() *Statement

Uint renders the uint identifier.

func (*Group) Uint16 

func (g *Group) Uint16() *Statement

Uint16 renders the uint16 identifier.

func (*Group) Uint32 

func (g *Group) Uint32() *Statement

Uint32 renders the uint32 identifier.

func (*Group) Uint64 

func (g *Group) Uint64() *Statement

Uint64 renders the uint64 identifier.

func (*Group) Uint8 

func (g *Group) Uint8() *Statement

Uint8 renders the uint8 identifier.

func (*Group) Uintptr 

func (g *Group) Uintptr() *Statement

Uintptr renders the uintptr identifier.

func (*Group) Values 

func (g *Group) Values(values ...Code) *Statement

Values renders a comma separated list enclosed by curly braces. Use for slice or composite literals.

func (*Group) ValuesFunc 

func (g *Group) ValuesFunc(f func(*Group)) *Statement

ValuesFunc renders a comma separated list enclosed by curly braces. Use for slice or composite literals.

func (*Group) Var 

func (g *Group) Var() *Statement

Var renders the var keyword.

type Statement 

type Statement []Code

Statement represents a simple list of code items. When rendered the items are separated by spaces.

func Add 

func Add(code ...Code) *Statement

Add appends the provided items to the statement.

Example 
ptr := Op("*")
c := Id("a").Op("=").Add(ptr).Id("b")
fmt.Printf("%#v", c)

Output:

a = *b
Example (Var) 
a := Id("a")
i := Int()
c := Var().Add(a, i)
fmt.Printf("%#v", c)

Output:

var a int

func Append 

func Append(args ...Code) *Statement

Append renders the append built-in function.

Example 
c := Append(Id("a"), Id("b"))
fmt.Printf("%#v", c)

Output:

append(a, b)
Example (More) 
c := Id("a").Op("=").Append(Id("a"), Id("b").Op("..."))
fmt.Printf("%#v", c)

Output:

a = append(a, b...)

func AppendFunc added in v0.9.1 

func AppendFunc(f func(*Group)) *Statement

AppendFunc renders the append built-in function.

func Assert 

func Assert(typ Code) *Statement

Assert renders a period followed by a single item enclosed by parenthesis. Use for type assertions.

Example 
c := List(Id("b"), Id("ok")).Op(":=").Id("a").Assert(Bool())
fmt.Printf("%#v", c)

Output:

b, ok := a.(bool)

func Block 

func Block(statements ...Code) *Statement

Block renders a statement list enclosed by curly braces. Use for code blocks. A special case applies when used directly after Case or Default, where the braces are omitted. This allows use in switch and select statements.

Example 
c := Func().Id("foo").Params().String().Block(
	Id("a").Op("=").Id("b"),
	Id("b").Op("++"),
	Return(Id("b")),
)
fmt.Printf("%#v", c)

Output:

func foo() string {
	a = b
	b++
	return b
}
Example (Case) 
c := Select().Block(
	Case(Op("<-").Id("done")).Block(
		Return(Nil()),
	),
	Case(List(Err(), Id("open")).Op(":=").Op("<-").Id("fail")).Block(
		If(Op("!").Id("open")).Block(
			Return(Err()),
		),
	),
)
fmt.Printf("%#v", c)

Output:

select {
case <-done:
	return nil
case err, open := <-fail:
	if !open {
		return err
	}
}
Example (Complex) 
collection := func(name string, key Code, value Code) *Statement {
	if key == nil {
		// slice
		return Var().Id(name).Index().Add(value)
	} else {
		// map
		return Var().Id(name).Map(key).Add(value)
	}
}
c := Func().Id("main").Params().Block(
	collection("foo", nil, String()),
	collection("bar", String(), Int()),
)
fmt.Printf("%#v", c)

Output:

func main() {
	var foo []string
	var bar map[string]int
}
Example (If) 
c := If(Id("a").Op(">").Lit(10)).Block(
	Id("a").Op("=").Id("a").Op("/").Lit(2),
)
fmt.Printf("%#v", c)

Output:

if a > 10 {
	a = a / 2
}

func BlockFunc 

func BlockFunc(f func(*Group)) *Statement

BlockFunc renders a statement list enclosed by curly braces. Use for code blocks. A special case applies when used directly after Case or Default, where the braces are omitted. This allows use in switch and select statements.

Example 
increment := true
name := "a"
c := Func().Id("a").Params().BlockFunc(func(g *Group) {
	g.Id(name).Op("=").Lit(1)
	if increment {
		g.Id(name).Op("++")
	} else {
		g.Id(name).Op("--")
	}
})
fmt.Printf("%#v", c)

Output:

func a() {
	a = 1
	a++
}
Example (Case) 
preventExitOnError := true
c := Select().Block(
	Case(Op("<-").Id("done")).Block(
		Return(Nil()),
	),
	Case(Err().Op(":=").Op("<-").Id("fail")).BlockFunc(func(g *Group) {
		if !preventExitOnError {
			g.Return(Err())
		} else {
			g.Qual("fmt", "Println").Call(Err())
		}
	}),
)
fmt.Printf("%#v", c)

Output:

select {
case <-done:
	return nil
case err := <-fail:
	fmt.Println(err)
}

func Bool 

func Bool() *Statement

Bool renders the bool identifier.

Example 
c := Var().Id("b").Bool()
fmt.Printf("%#v", c)

Output:

var b bool

func Break 

func Break() *Statement

Break renders the break keyword.

Example 
c := For(
	Id("i").Op(":=").Lit(0),
	Id("i").Op("<").Lit(10),
	Id("i").Op("++"),
).Block(
	If(Id("i").Op(">").Lit(5)).Block(
		Break(),
	),
)
fmt.Printf("%#v", c)

Output:

for i := 0; i < 10; i++ {
	if i > 5 {
		break
	}
}

func Byte 

func Byte() *Statement

Byte renders the byte identifier.

Example 
c := Id("b").Op(":=").Id("a").Assert(Byte())
fmt.Printf("%#v", c)

Output:

b := a.(byte)

func Call 

func Call(params ...Code) *Statement

Call renders a comma separated list enclosed by parenthesis. Use for function calls.

Example 
c := Qual("fmt", "Printf").Call(
	Lit("%#v: %T\n"),
	Id("a"),
	Id("b"),
)
fmt.Printf("%#v", c)

Output:

fmt.Printf("%#v: %T\n", a, b)
Example (Fmt) 
c := Id("a").Call(Lit("b"))
fmt.Printf("%#v", c)

Output:

a("b")

func CallFunc 

func CallFunc(f func(*Group)) *Statement

CallFunc renders a comma separated list enclosed by parenthesis. Use for function calls.

Example 
f := func(name string, second string) {
	c := Id("foo").CallFunc(func(g *Group) {
		g.Id(name)
		if second != "" {
			g.Lit(second)
		}
	})
	fmt.Printf("%#v\n", c)
}
f("a", "b")
f("c", "")

Output:

foo(a, "b")
foo(c)

func Cap 

func Cap(v Code) *Statement

Cap renders the cap built-in function.

Example 
c := Id("i").Op(":=").Cap(Id("v"))
fmt.Printf("%#v", c)

Output:

i := cap(v)

func Case 

func Case(cases ...Code) *Statement

Case renders the keyword followed by a comma separated list.

Example 
c := Switch(Id("person")).Block(
	Case(Id("John"), Id("Peter")).Block(
		Return(Lit("male")),
	),
	Case(Id("Gill")).Block(
		Return(Lit("female")),
	),
)
fmt.Printf("%#v", c)

Output:

switch person {
case John, Peter:
	return "male"
case Gill:
	return "female"
}

func CaseFunc 

func CaseFunc(f func(*Group)) *Statement

CaseFunc renders the keyword followed by a comma separated list.

Example 
samIsMale := false
c := Switch(Id("person")).Block(
	CaseFunc(func(g *Group) {
		g.Id("John")
		g.Id("Peter")
		if samIsMale {
			g.Id("Sam")
		}
	}).Block(
		Return(Lit("male")),
	),
	CaseFunc(func(g *Group) {
		g.Id("Gill")
		if !samIsMale {
			g.Id("Sam")
		}
	}).Block(
		Return(Lit("female")),
	),
)
fmt.Printf("%#v", c)

Output:

switch person {
case John, Peter:
	return "male"
case Gill, Sam:
	return "female"
}

func Chan 

func Chan() *Statement

Chan renders the chan keyword.

Example 
c := Func().Id("init").Params().Block(
	Id("c").Op(":=").Make(Chan().Qual("os", "Signal"), Lit(1)),
	Qual("os/signal", "Notify").Call(Id("c"), Qual("os", "Interrupt")),
	Qual("os/signal", "Notify").Call(Id("c"), Qual("syscall", "SIGTERM")),
	Go().Func().Params().Block(
		Op("<-").Id("c"),
		Id("cancel").Call(),
	).Call(),
)
fmt.Printf("%#v", c)

Output:

func init() {
	c := make(chan os.Signal, 1)
	signal.Notify(c, os.Interrupt)
	signal.Notify(c, syscall.SIGTERM)
	go func() {
		<-c
		cancel()
	}()
}

func Close 

func Close(c Code) *Statement

Close renders the close built-in function.

Example 
c := Block(
	Id("ch").Op(":=").Make(Chan().Struct()),
	Go().Func().Params().Block(
		Op("<-").Id("ch"),
		Qual("fmt", "Println").Call(Lit("done.")),
	).Call(),
	Close(Id("ch")),
)
fmt.Printf("%#v", c)

Output:

{
	ch := make(chan struct{})
	go func() {
		<-ch
		fmt.Println("done.")
	}()
	close(ch)
}

func Comment 

func Comment(str string) *Statement

Comment adds a comment. If the provided string contains a newline, the comment is formatted in multiline style. If the comment string starts with "//" or "/*", the automatic formatting is disabled and the string is rendered directly.

Example 
f := NewFile("a")
f.Comment("Foo returns the string \"foo\"")
f.Func().Id("Foo").Params().String().Block(
	Return(Lit("foo")).Comment("return the string foo"),
)
fmt.Printf("%#v", f)

Output:

package a

// Foo returns the string "foo"
func Foo() string {
	return "foo" // return the string foo
}
Example (Formatting_disabled) 
c := Id("foo").Call(Comment("/* inline */")).Comment("//no-space")
fmt.Printf("%#v", c)

Output:

foo( /* inline */ ) //no-space
Example (Multiline) 
c := Comment("a\nb")
fmt.Printf("%#v", c)

Output:

/*
a
b
*/

func Commentf 

func Commentf(format string, a ...interface{}) *Statement

Commentf adds a comment, using a format string and a list of parameters. If the provided string contains a newline, the comment is formatted in multiline style. If the comment string starts with "//" or "/*", the automatic formatting is disabled and the string is rendered directly.

Example 
name := "foo"
val := "bar"
c := Id(name).Op(":=").Lit(val).Commentf("%s is the string \"%s\"", name, val)
fmt.Printf("%#v", c)

Output:

foo := "bar" // foo is the string "bar"

func Complex 

func Complex(r Code, i Code) *Statement

Complex renders the complex built-in function.

Example 
c := Func().Id("main").Params().Block(
	Id("c1").Op(":=").Lit(1+3.75i),
	Id("c2").Op(":=").Complex(Lit(1), Lit(3.75)),
	Qual("fmt", "Println").Call(Id("c1").Op("==").Id("c2")),
)
fmt.Printf("%#v", c)

Output:

func main() {
	c1 := (1 + 3.75i)
	c2 := complex(1, 3.75)
	fmt.Println(c1 == c2)
}

func Complex128 

func Complex128() *Statement

Complex128 renders the complex128 identifier.

Example 
c := Func().Id("main").Params().Block(
	Var().Id("c").Complex128(),
	Id("c").Op("=").Lit(1+2i),
	Qual("fmt", "Println").Call(Id("c")),
)
fmt.Printf("%#v", c)

Output:

func main() {
	var c complex128
	c = (1 + 2i)
	fmt.Println(c)
}

func Complex64 

func Complex64() *Statement

Complex64 renders the complex64 identifier.

Example 
c := Func().Id("main").Params().Block(
	Var().Id("c64").Complex64(),
	Id("c64").Op("=").Complex(Lit(5), Float32().Parens(Lit(2))),
	Qual("fmt", "Printf").Call(Lit("%T\n"), Id("c64")),
)
fmt.Printf("%#v", c)

Output:

func main() {
	var c64 complex64
	c64 = complex(5, float32(2))
	fmt.Printf("%T\n", c64)
}

func Const 

func Const() *Statement

Const renders the const keyword.

func Continue 

func Continue() *Statement

Continue renders the continue keyword.

func Copy 

func Copy(dst Code, src Code) *Statement

Copy renders the copy built-in function.

func Default 

func Default() *Statement

Default renders the default keyword.

func Defer 

func Defer() *Statement

Defer renders the defer keyword.

Example 
c := Defer().Id("foo").Call()
fmt.Printf("%#v", c)

Output:

defer foo()

func Defs 

func Defs(definitions ...Code) *Statement

Defs renders a statement list enclosed in parenthesis. Use for definition lists.

Example 
c := Const().Defs(
	Id("a").Op("=").Lit("a"),
	Id("b").Op("=").Lit("b"),
)
fmt.Printf("%#v", c)

Output:

const (
	a = "a"
	b = "b"
)

func DefsFunc 

func DefsFunc(f func(*Group)) *Statement

DefsFunc renders a statement list enclosed in parenthesis. Use for definition lists.

func Delete 

func Delete(m Code, key Code) *Statement

Delete renders the delete built-in function.

func Do 

func Do(f func(*Statement)) *Statement

Do calls the provided function with the statement as a parameter. Use for embedding logic.

Example 
f := func(name string, isMap bool) *Statement {
	return Id(name).Op(":=").Do(func(s *Statement) {
		if isMap {
			s.Map(String()).String()
		} else {
			s.Index().String()
		}
	}).Values()
}
fmt.Printf("%#v\n%#v", f("a", true), f("b", false))

Output:

a := map[string]string{}
b := []string{}

func Dot added in v0.11.0 

func Dot(name string) *Statement

Dot renders a period followed by an identifier. Use for fields and selectors.

Example 
c := Qual("a.b/c", "Foo").Call().Dot("Bar").Index(Lit(0)).Dot("Baz")
fmt.Printf("%#v", c)

Output:

c.Foo().Bar[0].Baz

func Else 

func Else() *Statement

Else renders the else keyword.

func Empty 

func Empty() *Statement

Empty adds an empty item. Empty items render nothing but are followed by a separator in lists.

Example 
c := Id("a").Op(":=").Id("b").Index(Lit(1), Empty())
fmt.Printf("%#v", c)

Output:

a := b[1:]

func Err 

func Err() *Statement

Err renders the err identifier.

Example 
c := If(
	Err().Op(":=").Id("foo").Call(),
	Err().Op("!=").Nil(),
).Block(
	Return(Err()),
)
fmt.Printf("%#v", c)

Output:

if err := foo(); err != nil {
	return err
}

func Error 

func Error() *Statement

Error renders the error identifier.

func Fallthrough 

func Fallthrough() *Statement

Fallthrough renders the fallthrough keyword.

func False 

func False() *Statement

False renders the false identifier.

func Float32 

func Float32() *Statement

Float32 renders the float32 identifier.

func Float64 

func Float64() *Statement

Float64 renders the float64 identifier.

func For 

func For(conditions ...Code) *Statement

For renders the keyword followed by a semicolon separated list.

Example 
c := For(
	Id("i").Op(":=").Lit(0),
	Id("i").Op("<").Lit(10),
	Id("i").Op("++"),
).Block(
	Qual("fmt", "Println").Call(Id("i")),
)
fmt.Printf("%#v", c)

Output:

for i := 0; i < 10; i++ {
	fmt.Println(i)
}

func ForFunc 

func ForFunc(f func(*Group)) *Statement

ForFunc renders the keyword followed by a semicolon separated list.

func Func 

func Func() *Statement

Func renders the func keyword.

Example (Declaration) 
c := Func().Id("a").Params().Block()
fmt.Printf("%#v", c)

Output:

func a() {}
Example (Literal) 
c := Id("a").Op(":=").Func().Params().Block()
fmt.Printf("%#v", c)

Output:

a := func() {}

func Go 

func Go() *Statement

Go renders the go keyword.

func Goto 

func Goto() *Statement

Goto renders the goto keyword.

Example 
c := Goto().Id("Outer")
fmt.Printf("%#v", c)

Output:

goto Outer

func Id 

func Id(name string) *Statement

Id renders an identifier.

Example 
c := If(Id("i").Op("==").Id("j")).Block(
	Return(Id("i")),
)
fmt.Printf("%#v", c)

Output:

if i == j {
	return i
}
Example (Local) 
c := Id("a").Op(":=").Lit(1)
fmt.Printf("%#v", c)

Output:

a := 1
Example (Remote) 
f := NewFile("main")
f.Func().Id("main").Params().Block(
	Qual("fmt", "Println").Call(
		Lit("Hello, world"),
	),
)
fmt.Printf("%#v", f)

Output:

package main

import fmt "fmt"

func main() {
	fmt.Println("Hello, world")
}
Example (Select) 
c := Id("a").Dot("b").Dot("c").Call()
fmt.Printf("%#v", c)

Output:

a.b.c()

func If 

func If(conditions ...Code) *Statement

If renders the keyword followed by a semicolon separated list.

Example 
c := If(
	Err().Op(":=").Id("a").Call(),
	Err().Op("!=").Nil(),
).Block(
	Return(Err()),
)
fmt.Printf("%#v", c)

Output:

if err := a(); err != nil {
	return err
}

func IfFunc 

func IfFunc(f func(*Group)) *Statement

IfFunc renders the keyword followed by a semicolon separated list.

func Imag 

func Imag(c Code) *Statement

Imag renders the imag built-in function.

func Index 

func Index(items ...Code) *Statement

Index renders a colon separated list enclosed by square brackets. Use for array / slice indexes and definitions.

Example 
c := Var().Id("a").Index().String()
fmt.Printf("%#v", c)

Output:

var a []string
Example (Empty) 
c := Id("a").Op(":=").Id("b").Index(Lit(1), Empty())
fmt.Printf("%#v", c)

Output:

a := b[1:]
Example (Index) 
c := Id("a").Op(":=").Id("b").Index(Lit(0), Lit(1))
fmt.Printf("%#v", c)

Output:

a := b[0:1]

func IndexFunc 

func IndexFunc(f func(*Group)) *Statement

IndexFunc renders a colon separated list enclosed by square brackets. Use for array / slice indexes and definitions.

func Int 

func Int() *Statement

Int renders the int identifier.

func Int16 

func Int16() *Statement

Int16 renders the int16 identifier.

func Int32 

func Int32() *Statement

Int32 renders the int32 identifier.

func Int64 

func Int64() *Statement

Int64 renders the int64 identifier.

func Int8 

func Int8() *Statement

Int8 renders the int8 identifier.

func Interface 

func Interface(methods ...Code) *Statement

Interface renders the keyword followed by a method list enclosed by curly braces.

Example 
c := Type().Id("a").Interface(
	Id("b").Params().String(),
)
fmt.Printf("%#v", c)

Output:

type a interface {
	b() string
}
Example (Empty) 
c := Var().Id("a").Interface()
fmt.Printf("%#v", c)

Output:

var a interface{}

func InterfaceFunc 

func InterfaceFunc(f func(*Group)) *Statement

InterfaceFunc renders the keyword followed by a method list enclosed by curly braces.

func Iota 

func Iota() *Statement

Iota renders the iota identifier.

func Len 

func Len(v Code) *Statement

Len renders the len built-in function.

func Line 

func Line() *Statement

Line inserts a blank line.

func List 

func List(items ...Code) *Statement

List renders a comma separated list. Use for multiple return functions.

Example 
c := List(Id("a"), Err()).Op(":=").Id("b").Call()
fmt.Printf("%#v", c)

Output:

a, err := b()

func ListFunc 

func ListFunc(f func(*Group)) *Statement

ListFunc renders a comma separated list. Use for multiple return functions.

func Lit 

func Lit(v interface{}) *Statement

Lit renders a literal, using the format provided by the fmt package %#v verb.

Example 
c := Id("a").Op(":=").Lit("a")
fmt.Printf("%#v", c)

Output:

a := "a"
Example (Bool_false) 
c := Lit(false)
fmt.Printf("%#v", c)

Output:

false
Example (Bool_true) 
c := Lit(true)
fmt.Printf("%#v", c)

Output:

true
Example (Byte) 
// Lit can't tell the difference between byte and uint8. Use LitByte to
// render byte literals.
c := Lit(byte(0x1))
fmt.Printf("%#v", c)

Output:

uint8(0x1)
Example (Complex128) 
c := Lit(0 + 0i)
fmt.Printf("%#v", c)

Output:

(0 + 0i)
Example (Complex64) 
c := Lit(complex64(0 + 0i))
fmt.Printf("%#v", c)

Output:

complex64(0 + 0i)
Example (Float) 
c := Id("a").Op(":=").Lit(1.5)
fmt.Printf("%#v", c)

Output:

a := 1.5
Example (Float32) 
c := Lit(float32(1))
fmt.Printf("%#v", c)

Output:

float32(1)
Example (Float64_negative) 
c := Lit(-0.1)
fmt.Printf("%#v", c)

Output:

-0.1
Example (Float64_negative_whole) 
c := Lit(-1.0)
fmt.Printf("%#v", c)

Output:

-1.0
Example (Float64_one_point_zero) 
c := Lit(1.0)
fmt.Printf("%#v", c)

Output:

1.0
Example (Float64_zero) 
c := Lit(0.0)
fmt.Printf("%#v", c)

Output:

0.0
Example (Int) 
c := Lit(1)
fmt.Printf("%#v", c)

Output:

1
Example (Int16) 
c := Lit(int16(1))
fmt.Printf("%#v", c)

Output:

int16(1)
Example (Int32) 
c := Lit(int32(1))
fmt.Printf("%#v", c)

Output:

int32(1)
Example (Int64) 
c := Lit(int64(1))
fmt.Printf("%#v", c)

Output:

int64(1)
Example (Int8) 
c := Lit(int8(1))
fmt.Printf("%#v", c)

Output:

int8(1)
Example (Rune) 
// Lit can't tell the difference between rune and int32. Use LitRune to
// render rune literals.
c := Lit('x')
fmt.Printf("%#v", c)

Output:

int32(120)
Example (String) 
c := Lit("foo")
fmt.Printf("%#v", c)

Output:

"foo"
Example (Uint) 
c := Lit(uint(0x1))
fmt.Printf("%#v", c)

Output:

uint(0x1)
Example (Uint16) 
c := Lit(uint16(0x1))
fmt.Printf("%#v", c)

Output:

uint16(0x1)
Example (Uint32) 
c := Lit(uint32(0x1))
fmt.Printf("%#v", c)

Output:

uint32(0x1)
Example (Uint64) 
c := Lit(uint64(0x1))
fmt.Printf("%#v", c)

Output:

uint64(0x1)
Example (Uint8) 
c := Lit(uint8(0x1))
fmt.Printf("%#v", c)

Output:

uint8(0x1)
Example (Uintptr) 
c := Lit(uintptr(0x1))
fmt.Printf("%#v", c)

Output:

uintptr(0x1)

func LitByte added in v0.13.0 

func LitByte(v byte) *Statement

LitByte renders a byte literal.

Example 
c := LitByte(byte(1))
fmt.Printf("%#v", c)

Output:

byte(0x1)

func LitByteFunc added in v0.13.0 

func LitByteFunc(f func() byte) *Statement

LitByteFunc renders a byte literal. LitByteFunc generates the value to render by executing the provided function.

Example 
c := LitByteFunc(func() byte {
	return byte(2)
})
fmt.Printf("%#v", c)

Output:

byte(0x2)

func LitFunc 

func LitFunc(f func() interface{}) *Statement

LitFunc renders a literal, using the format provided by the fmt package %#v verb. LitFunc generates the value to render by executing the provided function.

Example 
c := Id("a").Op(":=").LitFunc(func() interface{} { return 1 + 1 })
fmt.Printf("%#v", c)

Output:

a := 2

func LitRune added in v0.13.0 

func LitRune(v rune) *Statement

LitRune renders a rune literal.

Example 
c := LitRune('x')
fmt.Printf("%#v", c)

Output:

'x'

func LitRuneFunc added in v0.13.0 

func LitRuneFunc(f func() rune) *Statement

LitRuneFunc renders a rune literal. LitRuneFunc generates the value to render by executing the provided function.

Example 
c := LitRuneFunc(func() rune {
	return '\t'
})
fmt.Printf("%#v", c)

Output:

'\t'

func Make 

func Make(args ...Code) *Statement

Make renders the make built-in function. The final parameter of the make function is optional, so it is represented by a variadic parameter list.

func Map 

func Map(typ Code) *Statement

Map renders the keyword followed by a single item enclosed by square brackets. Use for map definitions.

Example 
c := Id("a").Op(":=").Map(String()).String().Values()
fmt.Printf("%#v", c)

Output:

a := map[string]string{}

func New 

func New(typ Code) *Statement

New renders the new built-in function.

func Nil 

func Nil() *Statement

Nil renders the nil identifier.

func Null 

func Null() *Statement

Null adds a null item. Null items render nothing and are not followed by a separator in lists.

Example (And_nil) 
c := Func().Id("foo").Params(
	nil,
	Id("s").String(),
	Null(),
	Id("i").Int(),
).Block()
fmt.Printf("%#v", c)

Output:

func foo(s string, i int) {}
Example (Index) 
c := Id("a").Op(":=").Id("b").Index(Lit(1), Null())
fmt.Printf("%#v", c)

Output:

a := b[1]

func Op 

func Op(op string) *Statement

Op renders the provided operator / token.

Example 
c := Id("a").Op(":=").Id("b").Call()
fmt.Printf("%#v", c)

Output:

a := b()
Example (Complex_conditions) 
c := If(Params(Id("a").Op("||").Id("b")).Op("&&").Id("c")).Block()
fmt.Printf("%#v", c)

Output:

if (a || b) && c {
}
Example (Star) 
c := Id("a").Op("=").Op("*").Id("b")
fmt.Printf("%#v", c)

Output:

a = *b
Example (Variadic) 
c := Id("a").Call(Id("b").Op("..."))
fmt.Printf("%#v", c)

Output:

a(b...)

func Panic 

func Panic(v Code) *Statement

Panic renders the panic built-in function.

func Params 

func Params(params ...Code) *Statement

Params renders a comma separated list enclosed by parenthesis. Use for function parameters and method receivers.

Example 
c := Func().Params(
	Id("a").Id("A"),
).Id("foo").Params(
	Id("b"),
	Id("c").String(),
).String().Block(
	Return(Id("b").Op("+").Id("c")),
)
fmt.Printf("%#v", c)

Output:

func (a A) foo(b, c string) string {
	return b + c
}

func ParamsFunc 

func ParamsFunc(f func(*Group)) *Statement

ParamsFunc renders a comma separated list enclosed by parenthesis. Use for function parameters and method receivers.

func Parens 

func Parens(item Code) *Statement

Parens renders a single item in parenthesis. Use for type conversion or to specify evaluation order.

Example 
c := Id("b").Op(":=").Index().Byte().Parens(Id("s"))
fmt.Printf("%#v", c)

Output:

b := []byte(s)
Example (Order) 
c := Id("a").Op("/").Parens(Id("b").Op("+").Id("c"))
fmt.Printf("%#v", c)

Output:

a / (b + c)

func Print 

func Print(args ...Code) *Statement

Print renders the print built-in function.

func PrintFunc added in v0.9.1 

func PrintFunc(f func(*Group)) *Statement

PrintFunc renders the print built-in function.

func Println 

func Println(args ...Code) *Statement

Println renders the println built-in function.

func PrintlnFunc added in v0.9.1 

func PrintlnFunc(f func(*Group)) *Statement

PrintlnFunc renders the println built-in function.

func Qual 

func Qual(path, name string) *Statement

Qual renders a qualified identifier. Imports are automatically added when used with a File. If the path matches the local path, the package name is omitted. If package names conflict they are automatically renamed.

Example 
c := Qual("encoding/gob", "NewEncoder").Call()
fmt.Printf("%#v", c)

Output:

gob.NewEncoder()
Example (File) 
f := NewFilePath("a.b/c")
f.Func().Id("init").Params().Block(
	Qual("a.b/c", "Foo").Call().Comment("Local package - name is omitted."),
	Qual("d.e/f", "Bar").Call().Comment("Import is automatically added."),
	Qual("g.h/f", "Baz").Call().Comment("Colliding package name is renamed."),
)
fmt.Printf("%#v", f)

Output:

package c

import (
	f "d.e/f"
	f1 "g.h/f"
)

func init() {
	Foo()    // Local package - name is omitted.
	f.Bar()  // Import is automatically added.
	f1.Baz() // Colliding package name is renamed.
}
Example (Local) 
f := NewFilePath("a.b/c")
f.Func().Id("main").Params().Block(
	Qual("a.b/c", "D").Call(),
)
fmt.Printf("%#v", f)

Output:

package c

func main() {
	D()
}

func Range 

func Range() *Statement

Range renders the range keyword.

func Real 

func Real(c Code) *Statement

Real renders the real built-in function.

func Recover 

func Recover() *Statement

Recover renders the recover built-in function.

func Return 

func Return(results ...Code) *Statement

Return renders the keyword followed by a comma separated list.

Example 
c := Return(Id("a"), Id("b"))
fmt.Printf("%#v", c)

Output:

return a, b

func ReturnFunc 

func ReturnFunc(f func(*Group)) *Statement

ReturnFunc renders the keyword followed by a comma separated list.

func Rune 

func Rune() *Statement

Rune renders the rune identifier.

func Select 

func Select() *Statement

Select renders the select keyword.

func String 

func String() *Statement

String renders the string identifier.

func Struct 

func Struct(fields ...Code) *Statement

Struct renders the keyword followed by a field list enclosed by curly braces.

Example 
c := Type().Id("foo").Struct(
	List(Id("x"), Id("y")).Int(),
	Id("u").Float32(),
)
fmt.Printf("%#v", c)

Output:

type foo struct {
	x, y int
	u    float32
}
Example (Empty) 
c := Id("c").Op(":=").Make(Chan().Struct())
fmt.Printf("%#v", c)

Output:

c := make(chan struct{})

func StructFunc added in v0.9.3 

func StructFunc(f func(*Group)) *Statement

StructFunc renders the keyword followed by a field list enclosed by curly braces.

func Switch 

func Switch(conditions ...Code) *Statement

Switch renders the keyword followed by a semicolon separated list.

Example 
c := Switch(Id("value").Dot("Kind").Call()).Block(
	Case(Qual("reflect", "Float32"), Qual("reflect", "Float64")).Block(
		Return(Lit("float")),
	),
	Case(Qual("reflect", "Bool")).Block(
		Return(Lit("bool")),
	),
	Case(Qual("reflect", "Uintptr")).Block(
		Fallthrough(),
	),
	Default().Block(
		Return(Lit("none")),
	),
)
fmt.Printf("%#v", c)

Output:

switch value.Kind() {
case reflect.Float32, reflect.Float64:
	return "float"
case reflect.Bool:
	return "bool"
case reflect.Uintptr:
	fallthrough
default:
	return "none"
}

func SwitchFunc 

func SwitchFunc(f func(*Group)) *Statement

SwitchFunc renders the keyword followed by a semicolon separated list.

func Tag 

func Tag(items map[string]string) *Statement

Tag renders a struct tag

Example 
c := Type().Id("foo").Struct(
	Id("A").String().Tag(map[string]string{"json": "a"}),
	Id("B").Int().Tag(map[string]string{"json": "b", "bar": "baz"}),
)
fmt.Printf("%#v", c)

Output:

type foo struct {
	A string `json:"a"`
	B int    `bar:"baz" json:"b"`
}

func True 

func True() *Statement

True renders the true identifier.

func Type 

func Type() *Statement

Type renders the type keyword.

func Uint 

func Uint() *Statement

Uint renders the uint identifier.

func Uint16 

func Uint16() *Statement

Uint16 renders the uint16 identifier.

func Uint32 

func Uint32() *Statement

Uint32 renders the uint32 identifier.

func Uint64 

func Uint64() *Statement

Uint64 renders the uint64 identifier.

func Uint8 

func Uint8() *Statement

Uint8 renders the uint8 identifier.

func Uintptr 

func Uintptr() *Statement

Uintptr renders the uintptr identifier.

func Values 

func Values(values ...Code) *Statement

Values renders a comma separated list enclosed by curly braces. Use for slice or composite literals.

Example 
c := Index().String().Values(Lit("a"), Lit("b"))
fmt.Printf("%#v", c)

Output:

[]string{"a", "b"}
Example (Dict_composite) 
c := Op("&").Id("Person").Values(Dict{
	Id("Age"):  Lit(1),
	Id("Name"): Lit("a"),
})
fmt.Printf("%#v", c)

Output:

&Person{
	Age:  1,
	Name: "a",
}
Example (Dict_multiple) 
c := Map(String()).String().Values(Dict{
	Lit("a"): Lit("b"),
	Lit("c"): Lit("d"),
})
fmt.Printf("%#v", c)

Output:

map[string]string{
	"a": "b",
	"c": "d",
}
Example (Dict_single) 
c := Map(String()).String().Values(Dict{
	Lit("a"): Lit("b"),
})
fmt.Printf("%#v", c)

Output:

map[string]string{"a": "b"}

func ValuesFunc 

func ValuesFunc(f func(*Group)) *Statement

ValuesFunc renders a comma separated list enclosed by curly braces. Use for slice or composite literals.

Example 
c := Id("numbers").Op(":=").Index().Int().ValuesFunc(func(g *Group) {
	for i := 0; i <= 5; i++ {
		g.Lit(i)
	}
})
fmt.Printf("%#v", c)

Output:

numbers := []int{0, 1, 2, 3, 4, 5}

func Var 

func Var() *Statement

Var renders the var keyword.

func (*Statement) Add 

func (s *Statement) Add(code ...Code) *Statement

Add appends the provided items to the statement.

func (*Statement) Append 

func (s *Statement) Append(args ...Code) *Statement

Append renders the append built-in function.

func (*Statement) AppendFunc added in v0.9.1 

func (s *Statement) AppendFunc(f func(*Group)) *Statement

AppendFunc renders the append built-in function.

func (*Statement) Assert 

func (s *Statement) Assert(typ Code) *Statement

Assert renders a period followed by a single item enclosed by parenthesis. Use for type assertions.

func (*Statement) Block 

func (s *Statement) Block(statements ...Code) *Statement

Block renders a statement list enclosed by curly braces. Use for code blocks. A special case applies when used directly after Case or Default, where the braces are omitted. This allows use in switch and select statements.

func (*Statement) BlockFunc 

func (s *Statement) BlockFunc(f func(*Group)) *Statement

BlockFunc renders a statement list enclosed by curly braces. Use for code blocks. A special case applies when used directly after Case or Default, where the braces are omitted. This allows use in switch and select statements.

func (*Statement) Bool 

func (s *Statement) Bool() *Statement

Bool renders the bool identifier.

func (*Statement) Break 

func (s *Statement) Break() *Statement

Break renders the break keyword.

func (*Statement) Byte 

func (s *Statement) Byte() *Statement

Byte renders the byte identifier.

func (*Statement) Call 

func (s *Statement) Call(params ...Code) *Statement

Call renders a comma separated list enclosed by parenthesis. Use for function calls.

func (*Statement) CallFunc 

func (s *Statement) CallFunc(f func(*Group)) *Statement

CallFunc renders a comma separated list enclosed by parenthesis. Use for function calls.

func (*Statement) Cap 

func (s *Statement) Cap(v Code) *Statement

Cap renders the cap built-in function.

func (*Statement) Case 

func (s *Statement) Case(cases ...Code) *Statement

Case renders the keyword followed by a comma separated list.

func (*Statement) CaseFunc 

func (s *Statement) CaseFunc(f func(*Group)) *Statement

CaseFunc renders the keyword followed by a comma separated list.

func (*Statement) Chan 

func (s *Statement) Chan() *Statement

Chan renders the chan keyword.

func (*Statement) Clone 

func (s *Statement) Clone() *Statement

Clone makes a copy of the Statement, so further tokens can be appended without affecting the original.

Example (Broken) 
a := Id("a")
c := Block(
	a.Call(),
	a.Call(),
)
fmt.Printf("%#v", c)

Output:

{
	a()()
	a()()
}
Example (Fixed) 
a := Id("a")
c := Block(
	a.Clone().Call(),
	a.Clone().Call(),
)
fmt.Printf("%#v", c)

Output:

{
	a()
	a()
}

func (*Statement) Close 

func (s *Statement) Close(c Code) *Statement

Close renders the close built-in function.

func (*Statement) Comment 

func (s *Statement) Comment(str string) *Statement

Comment adds a comment. If the provided string contains a newline, the comment is formatted in multiline style. If the comment string starts with "//" or "/*", the automatic formatting is disabled and the string is rendered directly.

func (*Statement) Commentf 

func (s *Statement) Commentf(format string, a ...interface{}) *Statement

Commentf adds a comment, using a format string and a list of parameters. If the provided string contains a newline, the comment is formatted in multiline style. If the comment string starts with "//" or "/*", the automatic formatting is disabled and the string is rendered directly.

func (*Statement) Complex 

func (s *Statement) Complex(r Code, i Code) *Statement

Complex renders the complex built-in function.

func (*Statement) Complex128 

func (s *Statement) Complex128() *Statement

Complex128 renders the complex128 identifier.

func (*Statement) Complex64 

func (s *Statement) Complex64() *Statement

Complex64 renders the complex64 identifier.

func (*Statement) Const 

func (s *Statement) Const() *Statement

Const renders the const keyword.

func (*Statement) Continue 

func (s *Statement) Continue() *Statement

Continue renders the continue keyword.

func (*Statement) Copy 

func (s *Statement) Copy(dst Code, src Code) *Statement

Copy renders the copy built-in function.

func (*Statement) Default 

func (s *Statement) Default() *Statement

Default renders the default keyword.

func (*Statement) Defer 

func (s *Statement) Defer() *Statement

Defer renders the defer keyword.

func (*Statement) Defs 

func (s *Statement) Defs(definitions ...Code) *Statement

Defs renders a statement list enclosed in parenthesis. Use for definition lists.

func (*Statement) DefsFunc 

func (s *Statement) DefsFunc(f func(*Group)) *Statement

DefsFunc renders a statement list enclosed in parenthesis. Use for definition lists.

func (*Statement) Delete 

func (s *Statement) Delete(m Code, key Code) *Statement

Delete renders the delete built-in function.

func (*Statement) Do 

func (s *Statement) Do(f func(*Statement)) *Statement

Do calls the provided function with the statement as a parameter. Use for embedding logic.

func (*Statement) Dot added in v0.11.0 

func (s *Statement) Dot(name string) *Statement

Dot renders a period followed by an identifier. Use for fields and selectors.

func (*Statement) Else 

func (s *Statement) Else() *Statement

Else renders the else keyword.

func (*Statement) Empty 

func (s *Statement) Empty() *Statement

Empty adds an empty item. Empty items render nothing but are followed by a separator in lists.

func (*Statement) Err 

func (s *Statement) Err() *Statement

Err renders the err identifier.

func (*Statement) Error 

func (s *Statement) Error() *Statement

Error renders the error identifier.

func (*Statement) Fallthrough 

func (s *Statement) Fallthrough() *Statement

Fallthrough renders the fallthrough keyword.

func (*Statement) False 

func (s *Statement) False() *Statement

False renders the false identifier.

func (*Statement) Float32 

func (s *Statement) Float32() *Statement

Float32 renders the float32 identifier.

func (*Statement) Float64 

func (s *Statement) Float64() *Statement

Float64 renders the float64 identifier.

func (*Statement) For 

func (s *Statement) For(conditions ...Code) *Statement

For renders the keyword followed by a semicolon separated list.

func (*Statement) ForFunc 

func (s *Statement) ForFunc(f func(*Group)) *Statement

ForFunc renders the keyword followed by a semicolon separated list.

func (*Statement) Func 

func (s *Statement) Func() *Statement

Func renders the func keyword.

func (*Statement) Go 

func (s *Statement) Go() *Statement

Go renders the go keyword.

func (*Statement) GoString 

func (s *Statement) GoString() string

GoString renders the Statement for testing. Any error will cause a panic.

func (*Statement) Goto 

func (s *Statement) Goto() *Statement

Goto renders the goto keyword.

func (*Statement) Id 

func (s *Statement) Id(name string) *Statement

Id renders an identifier.

func (*Statement) If 

func (s *Statement) If(conditions ...Code) *Statement

If renders the keyword followed by a semicolon separated list.

func (*Statement) IfFunc 

func (s *Statement) IfFunc(f func(*Group)) *Statement

IfFunc renders the keyword followed by a semicolon separated list.

func (*Statement) Imag 

func (s *Statement) Imag(c Code) *Statement

Imag renders the imag built-in function.

func (*Statement) Index 

func (s *Statement) Index(items ...Code) *Statement

Index renders a colon separated list enclosed by square brackets. Use for array / slice indexes and definitions.

func (*Statement) IndexFunc 

func (s *Statement) IndexFunc(f func(*Group)) *Statement

IndexFunc renders a colon separated list enclosed by square brackets. Use for array / slice indexes and definitions.

func (*Statement) Int 

func (s *Statement) Int() *Statement

Int renders the int identifier.

func (*Statement) Int16 

func (s *Statement) Int16() *Statement

Int16 renders the int16 identifier.

func (*Statement) Int32 

func (s *Statement) Int32() *Statement

Int32 renders the int32 identifier.

func (*Statement) Int64 

func (s *Statement) Int64() *Statement

Int64 renders the int64 identifier.

func (*Statement) Int8 

func (s *Statement) Int8() *Statement

Int8 renders the int8 identifier.

func (*Statement) Interface 

func (s *Statement) Interface(methods ...Code) *Statement

Interface renders the keyword followed by a method list enclosed by curly braces.

func (*Statement) InterfaceFunc 

func (s *Statement) InterfaceFunc(f func(*Group)) *Statement

InterfaceFunc renders the keyword followed by a method list enclosed by curly braces.

func (*Statement) Iota 

func (s *Statement) Iota() *Statement

Iota renders the iota identifier.

func (*Statement) Len 

func (s *Statement) Len(v Code) *Statement

Len renders the len built-in function.

func (*Statement) Line 

func (s *Statement) Line() *Statement

Line inserts a blank line.

func (*Statement) List 

func (s *Statement) List(items ...Code) *Statement

List renders a comma separated list. Use for multiple return functions.

func (*Statement) ListFunc 

func (s *Statement) ListFunc(f func(*Group)) *Statement

ListFunc renders a comma separated list. Use for multiple return functions.

func (*Statement) Lit 

func (s *Statement) Lit(v interface{}) *Statement

Lit renders a literal, using the format provided by the fmt package %#v verb.

func (*Statement) LitByte added in v0.13.0 

func (s *Statement) LitByte(v byte) *Statement

LitByte renders a byte literal.

func (*Statement) LitByteFunc added in v0.13.0 

func (s *Statement) LitByteFunc(f func() byte) *Statement

LitByteFunc renders a byte literal. LitByteFunc generates the value to render by executing the provided function.

func (*Statement) LitFunc 

func (s *Statement) LitFunc(f func() interface{}) *Statement

LitFunc renders a literal, using the format provided by the fmt package %#v verb. LitFunc generates the value to render by executing the provided function.

func (*Statement) LitRune added in v0.13.0 

func (s *Statement) LitRune(v rune) *Statement

LitRune renders a rune literal.

func (*Statement) LitRuneFunc added in v0.13.0 

func (s *Statement) LitRuneFunc(f func() rune) *Statement

LitRuneFunc renders a rune literal. LitRuneFunc generates the value to render by executing the provided function.

func (*Statement) Make 

func (s *Statement) Make(args ...Code) *Statement

Make renders the make built-in function. The final parameter of the make function is optional, so it is represented by a variadic parameter list.

func (*Statement) Map 

func (s *Statement) Map(typ Code) *Statement

Map renders the keyword followed by a single item enclosed by square brackets. Use for map definitions.

func (*Statement) New 

func (s *Statement) New(typ Code) *Statement

New renders the new built-in function.

func (*Statement) Nil 

func (s *Statement) Nil() *Statement

Nil renders the nil identifier.

func (*Statement) Null 

func (s *Statement) Null() *Statement

Null adds a null item. Null items render nothing and are not followed by a separator in lists.

func (*Statement) Op 

func (s *Statement) Op(op string) *Statement

Op renders the provided operator / token.

func (*Statement) Panic 

func (s *Statement) Panic(v Code) *Statement

Panic renders the panic built-in function.

func (*Statement) Params 

func (s *Statement) Params(params ...Code) *Statement

Params renders a comma separated list enclosed by parenthesis. Use for function parameters and method receivers.

func (*Statement) ParamsFunc 

func (s *Statement) ParamsFunc(f func(*Group)) *Statement

ParamsFunc renders a comma separated list enclosed by parenthesis. Use for function parameters and method receivers.

func (*Statement) Parens 

func (s *Statement) Parens(item Code) *Statement

Parens renders a single item in parenthesis. Use for type conversion or to specify evaluation order.

func (*Statement) Print 

func (s *Statement) Print(args ...Code) *Statement

Print renders the print built-in function.

func (*Statement) PrintFunc added in v0.9.1 

func (s *Statement) PrintFunc(f func(*Group)) *Statement

PrintFunc renders the print built-in function.

func (*Statement) Println 

func (s *Statement) Println(args ...Code) *Statement

Println renders the println built-in function.

func (*Statement) PrintlnFunc added in v0.9.1 

func (s *Statement) PrintlnFunc(f func(*Group)) *Statement

PrintlnFunc renders the println built-in function.

func (*Statement) Qual 

func (s *Statement) Qual(path, name string) *Statement

Qual renders a qualified identifier. Imports are automatically added when used with a File. If the path matches the local path, the package name is omitted. If package names conflict they are automatically renamed.

func (*Statement) Range 

func (s *Statement) Range() *Statement

Range renders the range keyword.

func (*Statement) Real 

func (s *Statement) Real(c Code) *Statement

Real renders the real built-in function.

func (*Statement) Recover 

func (s *Statement) Recover() *Statement

Recover renders the recover built-in function.

func (*Statement) Render added in v0.15.0 

func (s *Statement) Render(writer io.Writer) error

Render renders the Statement to the provided writer.

func (*Statement) Return 

func (s *Statement) Return(results ...Code) *Statement

Return renders the keyword followed by a comma separated list.

func (*Statement) ReturnFunc 

func (s *Statement) ReturnFunc(f func(*Group)) *Statement

ReturnFunc renders the keyword followed by a comma separated list.

func (*Statement) Rune 

func (s *Statement) Rune() *Statement

Rune renders the rune identifier.

func (*Statement) Select 

func (s *Statement) Select() *Statement

Select renders the select keyword.

func (*Statement) String 

func (s *Statement) String() *Statement

String renders the string identifier.

func (*Statement) Struct 

func (s *Statement) Struct(fields ...Code) *Statement

Struct renders the keyword followed by a field list enclosed by curly braces.

func (*Statement) StructFunc added in v0.9.3 

func (s *Statement) StructFunc(f func(*Group)) *Statement

StructFunc renders the keyword followed by a field list enclosed by curly braces.

func (*Statement) Switch 

func (s *Statement) Switch(conditions ...Code) *Statement

Switch renders the keyword followed by a semicolon separated list.

func (*Statement) SwitchFunc 

func (s *Statement) SwitchFunc(f func(*Group)) *Statement

SwitchFunc renders the keyword followed by a semicolon separated list.

func (*Statement) Tag 

func (s *Statement) Tag(items map[string]string) *Statement

Tag renders a struct tag

func (*Statement) True 

func (s *Statement) True() *Statement

True renders the true identifier.

func (*Statement) Type 

func (s *Statement) Type() *Statement

Type renders the type keyword.

func (*Statement) Uint 

func (s *Statement) Uint() *Statement

Uint renders the uint identifier.

func (*Statement) Uint16 

func (s *Statement) Uint16() *Statement

Uint16 renders the uint16 identifier.

func (*Statement) Uint32 

func (s *Statement) Uint32() *Statement

Uint32 renders the uint32 identifier.

func (*Statement) Uint64 

func (s *Statement) Uint64() *Statement

Uint64 renders the uint64 identifier.

func (*Statement) Uint8 

func (s *Statement) Uint8() *Statement

Uint8 renders the uint8 identifier.

func (*Statement) Uintptr 

func (s *Statement) Uintptr() *Statement

Uintptr renders the uintptr identifier.

func (*Statement) Values 

func (s *Statement) Values(values ...Code) *Statement

Values renders a comma separated list enclosed by curly braces. Use for slice or composite literals.

func (*Statement) ValuesFunc 

func (s *Statement) ValuesFunc(f func(*Group)) *Statement

ValuesFunc renders a comma separated list enclosed by curly braces. Use for slice or composite literals.

func (*Statement) Var 

func (s *Statement) Var() *Statement

Var renders the var keyword.

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