Package ast

func FileExports ¶

func FileExports(src *File) bool

FileExports trims the AST for a Go source file in place such that only exported nodes remain: all top-level identifiers which are not exported and their associated information (such as type, initial value, or function body) are removed. Non-exported fields and methods of exported types are stripped. The File.Comments list is not changed.

FileExports reports whether there are exported declarations.

func FilterDecl ¶

func FilterDecl(decl Decl, f Filter) bool

FilterDecl trims the AST for a Go declaration in place by removing all names (including struct field and interface method names, but not from parameter lists) that don't pass through the filter f.

FilterDecl reports whether there are any declared names left after filtering.

func FilterFile ¶

func FilterFile(src *File, f Filter) bool

FilterFile trims the AST for a Go file in place by removing all names from top-level declarations (including struct field and interface method names, but not from parameter lists) that don't pass through the filter f. If the declaration is empty afterwards, the declaration is removed from the AST. Import declarations are always removed. The File.Comments list is not changed.

FilterFile reports whether there are any top-level declarations left after filtering.

func FilterPackage ¶

func FilterPackage(pkg *Package, f Filter) bool

FilterPackage trims the AST for a Go package in place by removing all names from top-level declarations (including struct field and interface method names, but not from parameter lists) that don't pass through the filter f. If the declaration is empty afterwards, the declaration is removed from the AST. The pkg.Files list is not changed, so that file names and top-level package comments don't get lost.

FilterPackage reports whether there are any top-level declarations left after filtering.

func Fprint ¶

func Fprint(w io.Writer, fset *token.FileSet, x interface{}, f FieldFilter) error

Fprint prints the (sub-)tree starting at AST node x to w. If fset != nil, position information is interpreted relative to that file set. Otherwise positions are printed as integer values (file set specific offsets).

A non-nil FieldFilter f may be provided to control the output: struct fields for which f(fieldname, fieldvalue) is true are printed; all others are filtered from the output. Unexported struct fields are never printed.

func Inspect ¶

func Inspect(node Node, f func(Node) bool)

Inspect traverses an AST in depth-first order: It starts by calling f(node); node must not be nil. If f returns true, Inspect invokes f recursively for each of the non-nil children of node, followed by a call of f(nil).

// src is the input for which we want to inspect the AST.
src := `
package p
const c = 1.0
var X = f(3.14)*2 + c
`

// Create the AST by parsing src.
fset := token.NewFileSet() // positions are relative to fset
f, err := parser.ParseFile(fset, "src.go", src, 0)
if err != nil {
		panic(err)
}

// Inspect the AST and print all identifiers and literals.
ast.Inspect(f, func(n ast.Node) bool {
		var s string
		switch x := n.(type) {
		case *ast.BasicLit:
				s = x.Value
		case *ast.Ident:
				s = x.Name
		}
		if s != "" {
				fmt.Printf("%s:\t%s\n", fset.Position(n.Pos()), s)
		}
		return true
})

src.go:2:9:	p
src.go:3:7:	c
src.go:3:11:	1.0
src.go:4:5:	X
src.go:4:9:	f
src.go:4:11:	3.14
src.go:4:17:	2
src.go:4:21:	c

func IsExported ¶

func IsExported(name string) bool

IsExported reports whether name starts with an upper-case letter.

func NotNilFilter ¶

func NotNilFilter(_ string, v reflect.Value) bool

NotNilFilter returns true for field values that are not nil; it returns false otherwise.

func PackageExports ¶

func PackageExports(pkg *Package) bool

PackageExports trims the AST for a Go package in place such that only exported nodes remain. The pkg.Files list is not changed, so that file names and top-level package comments don't get lost.

PackageExports reports whether there are exported declarations; it returns false otherwise.

func Print ¶

func Print(fset *token.FileSet, x interface{}) error

Print prints x to standard output, skipping nil fields. Print(fset, x) is the same as Fprint(os.Stdout, fset, x, NotNilFilter).

// src is the input for which we want to print the AST.
src := `
package main
func main() {
		println("Hello, World!")
}
`

// Create the AST by parsing src.
fset := token.NewFileSet() // positions are relative to fset
f, err := parser.ParseFile(fset, "", src, 0)
if err != nil {
		panic(err)
}

// Print the AST.
ast.Print(fset, f)

		 0	*ast.File {
		 1	.	Package: 2:1
		 2	.	Name: *ast.Ident {
		 3	.	.	NamePos: 2:9
		 4	.	.	Name: "main"
		 5	.	}
		 6	.	Decls: []ast.Decl (len = 1) {
		 7	.	.	0: *ast.FuncDecl {
		 8	.	.	.	Name: *ast.Ident {
		 9	.	.	.	.	NamePos: 3:6
		10	.	.	.	.	Name: "main"
		11	.	.	.	.	Obj: *ast.Object {
		12	.	.	.	.	.	Kind: func
		13	.	.	.	.	.	Name: "main"
		14	.	.	.	.	.	Decl: *(obj @ 7)
		15	.	.	.	.	}
		16	.	.	.	}
		17	.	.	.	Type: *ast.FuncType {
		18	.	.	.	.	Func: 3:1
		19	.	.	.	.	Params: *ast.FieldList {
		20	.	.	.	.	.	Opening: 3:10
		21	.	.	.	.	.	Closing: 3:11
		22	.	.	.	.	}
		23	.	.	.	}
		24	.	.	.	Body: *ast.BlockStmt {
		25	.	.	.	.	Lbrace: 3:13
		26	.	.	.	.	List: []ast.Stmt (len = 1) {
		27	.	.	.	.	.	0: *ast.ExprStmt {
		28	.	.	.	.	.	.	X: *ast.CallExpr {
		29	.	.	.	.	.	.	.	Fun: *ast.Ident {
		30	.	.	.	.	.	.	.	.	NamePos: 4:2
		31	.	.	.	.	.	.	.	.	Name: "println"
		32	.	.	.	.	.	.	.	}
		33	.	.	.	.	.	.	.	Lparen: 4:9
		34	.	.	.	.	.	.	.	Args: []ast.Expr (len = 1) {
		35	.	.	.	.	.	.	.	.	0: *ast.BasicLit {
		36	.	.	.	.	.	.	.	.	.	ValuePos: 4:10
		37	.	.	.	.	.	.	.	.	.	Kind: STRING
		38	.	.	.	.	.	.	.	.	.	Value: "\"Hello, World!\""
		39	.	.	.	.	.	.	.	.	}
		40	.	.	.	.	.	.	.	}
		41	.	.	.	.	.	.	.	Ellipsis: -
		42	.	.	.	.	.	.	.	Rparen: 4:25
		43	.	.	.	.	.	.	}
		44	.	.	.	.	.	}
		45	.	.	.	.	}
		46	.	.	.	.	Rbrace: 5:1
		47	.	.	.	}
		48	.	.	}
		49	.	}
		50	.	Scope: *ast.Scope {
		51	.	.	Objects: map[string]*ast.Object (len = 1) {
		52	.	.	.	"main": *(obj @ 11)
		53	.	.	}
		54	.	}
		55	.	Unresolved: []*ast.Ident (len = 1) {
		56	.	.	0: *(obj @ 29)
		57	.	}
		58	}

func SortImports ¶

func SortImports(fset *token.FileSet, f *File)

SortImports sorts runs of consecutive import lines in import blocks in f. It also removes duplicate imports when it is possible to do so without data loss.

func Walk ¶

func Walk(v Visitor, node Node)

Walk traverses an AST in depth-first order: It starts by calling v.Visit(node); node must not be nil. If the visitor w returned by v.Visit(node) is not nil, Walk is invoked recursively with visitor w for each of the non-nil children of node, followed by a call of w.Visit(nil).

type ArrayType ¶

An ArrayType node represents an array or slice type.

type ArrayType struct {
		Lbrack token.Pos // position of "["
		Len		Expr			// Ellipsis node for [...]T array types, nil for slice types
		Elt		Expr			// element type
}

func (*ArrayType) End ¶

func (x *ArrayType) End() token.Pos

func (*ArrayType) Pos ¶

func (x *ArrayType) Pos() token.Pos

type AssignStmt ¶

An AssignStmt node represents an assignment or a short variable declaration.

type AssignStmt struct {
		Lhs		[]Expr
		TokPos token.Pos	 // position of Tok
		Tok		token.Token // assignment token, DEFINE
		Rhs		[]Expr
}

func (*AssignStmt) End ¶

func (s *AssignStmt) End() token.Pos

func (*AssignStmt) Pos ¶

func (s *AssignStmt) Pos() token.Pos

type BadDecl ¶

A BadDecl node is a placeholder for a declaration containing syntax errors for which a correct declaration node cannot be created.

type BadDecl struct {
		From, To token.Pos // position range of bad declaration
}

func (*BadDecl) End ¶

func (d *BadDecl) End() token.Pos

func (*BadDecl) Pos ¶

func (d *BadDecl) Pos() token.Pos

type BadExpr ¶

A BadExpr node is a placeholder for an expression containing syntax errors for which a correct expression node cannot be created.

type BadExpr struct {
		From, To token.Pos // position range of bad expression
}

func (*BadExpr) End ¶

func (x *BadExpr) End() token.Pos

func (*BadExpr) Pos ¶

func (x *BadExpr) Pos() token.Pos

type BadStmt ¶

A BadStmt node is a placeholder for statements containing syntax errors for which no correct statement nodes can be created.

type BadStmt struct {
		From, To token.Pos // position range of bad statement
}

func (*BadStmt) End ¶

func (s *BadStmt) End() token.Pos

func (*BadStmt) Pos ¶

func (s *BadStmt) Pos() token.Pos

type BasicLit ¶

A BasicLit node represents a literal of basic type.

type BasicLit struct {
		ValuePos token.Pos	 // literal position
		Kind		 token.Token // token.INT, token.FLOAT, token.IMAG, token.CHAR, or token.STRING
		Value		string			// literal string; e.g. 42, 0x7f, 3.14, 1e-9, 2.4i, 'a', '\x7f', "foo" or `\m\n\o`
}

func (*BasicLit) End ¶

func (x *BasicLit) End() token.Pos

func (*BasicLit) Pos ¶

func (x *BasicLit) Pos() token.Pos

type BinaryExpr ¶

A BinaryExpr node represents a binary expression.

type BinaryExpr struct {
		X		 Expr				// left operand
		OpPos token.Pos	 // position of Op
		Op		token.Token // operator
		Y		 Expr				// right operand
}

func (*BinaryExpr) End ¶

func (x *BinaryExpr) End() token.Pos

func (*BinaryExpr) Pos ¶

func (x *BinaryExpr) Pos() token.Pos

type BlockStmt ¶

A BlockStmt node represents a braced statement list.

type BlockStmt struct {
		Lbrace token.Pos // position of "{"
		List	 []Stmt
		Rbrace token.Pos // position of "}", if any (may be absent due to syntax error)
}

func (*BlockStmt) End ¶

func (s *BlockStmt) End() token.Pos

func (*BlockStmt) Pos ¶

func (s *BlockStmt) Pos() token.Pos

type BranchStmt ¶

A BranchStmt node represents a break, continue, goto, or fallthrough statement.

type BranchStmt struct {
		TokPos token.Pos	 // position of Tok
		Tok		token.Token // keyword token (BREAK, CONTINUE, GOTO, FALLTHROUGH)
		Label	*Ident			// label name; or nil
}

func (*BranchStmt) End ¶

func (s *BranchStmt) End() token.Pos

func (*BranchStmt) Pos ¶

func (s *BranchStmt) Pos() token.Pos

type CallExpr ¶

A CallExpr node represents an expression followed by an argument list.

type CallExpr struct {
		Fun			Expr			// function expression
		Lparen	 token.Pos // position of "("
		Args		 []Expr		// function arguments; or nil
		Ellipsis token.Pos // position of "..." (token.NoPos if there is no "...")
		Rparen	 token.Pos // position of ")"
}

func (*CallExpr) End ¶

func (x *CallExpr) End() token.Pos

func (*CallExpr) Pos ¶

func (x *CallExpr) Pos() token.Pos

type CaseClause ¶

A CaseClause represents a case of an expression or type switch statement.

type CaseClause struct {
		Case	token.Pos // position of "case" or "default" keyword
		List	[]Expr		// list of expressions or types; nil means default case
		Colon token.Pos // position of ":"
		Body	[]Stmt		// statement list; or nil
}

func (*CaseClause) End ¶

func (s *CaseClause) End() token.Pos

func (*CaseClause) Pos ¶

func (s *CaseClause) Pos() token.Pos

type ChanDir ¶

The direction of a channel type is indicated by a bit mask including one or both of the following constants.

type ChanDir int

const (
		SEND ChanDir = 1 << iota
		RECV
)

type ChanType ¶

A ChanType node represents a channel type.

type ChanType struct {
		Begin token.Pos // position of "chan" keyword or "<-" (whichever comes first)
		Arrow token.Pos // position of "<-" (token.NoPos if there is no "<-"); added in Go 1.1
		Dir	 ChanDir	 // channel direction
		Value Expr			// value type
}

func (*ChanType) End ¶

func (x *ChanType) End() token.Pos

func (*ChanType) Pos ¶

func (x *ChanType) Pos() token.Pos

type CommClause ¶

A CommClause node represents a case of a select statement.

type CommClause struct {
		Case	token.Pos // position of "case" or "default" keyword
		Comm	Stmt			// send or receive statement; nil means default case
		Colon token.Pos // position of ":"
		Body	[]Stmt		// statement list; or nil
}

func (*CommClause) End ¶

func (s *CommClause) End() token.Pos

func (*CommClause) Pos ¶

func (s *CommClause) Pos() token.Pos

type Comment ¶

A Comment node represents a single //-style or /*-style comment.

The Text field contains the comment text without carriage returns (\r) that may have been present in the source. Because a comment's end position is computed using len(Text), the position reported by End() does not match the true source end position for comments containing carriage returns.

type Comment struct {
		Slash token.Pos // position of "/" starting the comment
		Text	string		// comment text (excluding '\n' for //-style comments)
}

func (*Comment) End ¶

func (c *Comment) End() token.Pos

func (*Comment) Pos ¶

func (c *Comment) Pos() token.Pos

type CommentGroup ¶

A CommentGroup represents a sequence of comments with no other tokens and no empty lines between.

type CommentGroup struct {
		List []*Comment // len(List) > 0
}

func (*CommentGroup) End ¶

func (g *CommentGroup) End() token.Pos

func (*CommentGroup) Pos ¶

func (g *CommentGroup) Pos() token.Pos

func (*CommentGroup) Text ¶

func (g *CommentGroup) Text() string

Text returns the text of the comment. Comment markers (//, /*, and */), the first space of a line comment, and leading and trailing empty lines are removed. Comment directives like "//line" and "//go:noinline" are also removed. Multiple empty lines are reduced to one, and trailing space on lines is trimmed. Unless the result is empty, it is newline-terminated.

type CommentMap ¶ 1.1

A CommentMap maps an AST node to a list of comment groups associated with it. See NewCommentMap for a description of the association.

type CommentMap map[Node][]*CommentGroup

// src is the input for which we create the AST that we
// are going to manipulate.
src := `
// This is the package comment.
package main

// This comment is associated with the hello constant.
const hello = "Hello, World!" // line comment 1

// This comment is associated with the foo variable.
var foo = hello // line comment 2

// This comment is associated with the main function.
func main() {
		fmt.Println(hello) // line comment 3
}
`

// Create the AST by parsing src.
fset := token.NewFileSet() // positions are relative to fset
f, err := parser.ParseFile(fset, "src.go", src, parser.ParseComments)
if err != nil {
		panic(err)
}

// Create an ast.CommentMap from the ast.File's comments.
// This helps keeping the association between comments
// and AST nodes.
cmap := ast.NewCommentMap(fset, f, f.Comments)

// Remove the first variable declaration from the list of declarations.
for i, decl := range f.Decls {
		if gen, ok := decl.(*ast.GenDecl); ok && gen.Tok == token.VAR {
				copy(f.Decls[i:], f.Decls[i+1:])
				f.Decls = f.Decls[:len(f.Decls)-1]
				break
		}
}

// Use the comment map to filter comments that don't belong anymore
// (the comments associated with the variable declaration), and create
// the new comments list.
f.Comments = cmap.Filter(f).Comments()

// Print the modified AST.
var buf bytes.Buffer
if err := format.Node(&buf, fset, f); err != nil {
		panic(err)
}
fmt.Printf("%s", buf.Bytes())

// This is the package comment.
package main

// This comment is associated with the hello constant.
const hello = "Hello, World!" // line comment 1

// This comment is associated with the main function.
func main() {
	fmt.Println(hello) // line comment 3
}

func NewCommentMap ¶ 1.1

func NewCommentMap(fset *token.FileSet, node Node, comments []*CommentGroup) CommentMap

NewCommentMap creates a new comment map by associating comment groups of the comments list with the nodes of the AST specified by node.

A comment group g is associated with a node n if:

- g starts on the same line as n ends
- g starts on the line immediately following n, and there is
	at least one empty line after g and before the next node
- g starts before n and is not associated to the node before n
	via the previous rules

NewCommentMap tries to associate a comment group to the "largest" node possible: For instance, if the comment is a line comment trailing an assignment, the comment is associated with the entire assignment rather than just the last operand in the assignment.

func (CommentMap) Comments ¶ 1.1

func (cmap CommentMap) Comments() []*CommentGroup

Comments returns the list of comment groups in the comment map. The result is sorted in source order.

func (CommentMap) Filter ¶ 1.1

func (cmap CommentMap) Filter(node Node) CommentMap

Filter returns a new comment map consisting of only those entries of cmap for which a corresponding node exists in the AST specified by node.

func (CommentMap) String ¶ 1.1

func (cmap CommentMap) String() string

func (CommentMap) Update ¶ 1.1

func (cmap CommentMap) Update(old, new Node) Node

Update replaces an old node in the comment map with the new node and returns the new node. Comments that were associated with the old node are associated with the new node.

type CompositeLit ¶

A CompositeLit node represents a composite literal.

type CompositeLit struct {
		Type			 Expr			// literal type; or nil
		Lbrace		 token.Pos // position of "{"
		Elts			 []Expr		// list of composite elements; or nil
		Rbrace		 token.Pos // position of "}"
		Incomplete bool			// true if (source) expressions are missing in the Elts list; added in Go 1.11
}

func (*CompositeLit) End ¶

func (x *CompositeLit) End() token.Pos

func (*CompositeLit) Pos ¶

func (x *CompositeLit) Pos() token.Pos

type Decl ¶

All declaration nodes implement the Decl interface.

type Decl interface {
		Node
		// contains filtered or unexported methods
}

type DeclStmt ¶

A DeclStmt node represents a declaration in a statement list.

type DeclStmt struct {
		Decl Decl // *GenDecl with CONST, TYPE, or VAR token
}

func (*DeclStmt) End ¶

func (s *DeclStmt) End() token.Pos

func (*DeclStmt) Pos ¶

func (s *DeclStmt) Pos() token.Pos

type DeferStmt ¶

A DeferStmt node represents a defer statement.

type DeferStmt struct {
		Defer token.Pos // position of "defer" keyword
		Call	*CallExpr
}

func (*DeferStmt) End ¶

func (s *DeferStmt) End() token.Pos

func (*DeferStmt) Pos ¶

func (s *DeferStmt) Pos() token.Pos

type Ellipsis ¶

An Ellipsis node stands for the "..." type in a parameter list or the "..." length in an array type.

type Ellipsis struct {
		Ellipsis token.Pos // position of "..."
		Elt			Expr			// ellipsis element type (parameter lists only); or nil
}

func (*Ellipsis) End ¶

func (x *Ellipsis) End() token.Pos

func (*Ellipsis) Pos ¶

func (x *Ellipsis) Pos() token.Pos

type EmptyStmt ¶

An EmptyStmt node represents an empty statement. The "position" of the empty statement is the position of the immediately following (explicit or implicit) semicolon.

type EmptyStmt struct {
		Semicolon token.Pos // position of following ";"
		Implicit	bool			// if set, ";" was omitted in the source; added in Go 1.5
}

func (*EmptyStmt) End ¶

func (s *EmptyStmt) End() token.Pos

func (*EmptyStmt) Pos ¶

func (s *EmptyStmt) Pos() token.Pos

type Expr ¶

All expression nodes implement the Expr interface.

type Expr interface {
		Node
		// contains filtered or unexported methods
}

type ExprStmt ¶

An ExprStmt node represents a (stand-alone) expression in a statement list.

type ExprStmt struct {
		X Expr // expression
}

func (*ExprStmt) End ¶

func (s *ExprStmt) End() token.Pos

func (*ExprStmt) Pos ¶

func (s *ExprStmt) Pos() token.Pos

type Field ¶

A Field represents a Field declaration list in a struct type, a method list in an interface type, or a parameter/result declaration in a signature. Field.Names is nil for unnamed parameters (parameter lists which only contain types) and embedded struct fields. In the latter case, the field name is the type name. Field.Names contains a single name "type" for elements of interface type lists. Types belonging to the same type list share the same "type" identifier which also records the position of that keyword.

type Field struct {
		Doc		 *CommentGroup // associated documentation; or nil
		Names	 []*Ident			// field/method/(type) parameter names, or type "type"; or nil
		Type		Expr					// field/method/parameter type, type list type; or nil
		Tag		 *BasicLit		 // field tag; or nil
		Comment *CommentGroup // line comments; or nil
}

func (*Field) End ¶

func (f *Field) End() token.Pos

func (*Field) Pos ¶

func (f *Field) Pos() token.Pos

type FieldFilter ¶

A FieldFilter may be provided to Fprint to control the output.

type FieldFilter func(name string, value reflect.Value) bool

type FieldList ¶

A FieldList represents a list of Fields, enclosed by parentheses or braces.

type FieldList struct {
		Opening token.Pos // position of opening parenthesis/brace, if any
		List		[]*Field	// field list; or nil
		Closing token.Pos // position of closing parenthesis/brace, if any
}

func (*FieldList) End ¶

func (f *FieldList) End() token.Pos

func (*FieldList) NumFields ¶

func (f *FieldList) NumFields() int

NumFields returns the number of parameters or struct fields represented by a FieldList.

func (*FieldList) Pos ¶

func (f *FieldList) Pos() token.Pos

type File ¶

A File node represents a Go source file.

The Comments list contains all comments in the source file in order of appearance, including the comments that are pointed to from other nodes via Doc and Comment fields.

For correct printing of source code containing comments (using packages go/format and go/printer), special care must be taken to update comments when a File's syntax tree is modified: For printing, comments are interspersed between tokens based on their position. If syntax tree nodes are removed or moved, relevant comments in their vicinity must also be removed (from the File.Comments list) or moved accordingly (by updating their positions). A CommentMap may be used to facilitate some of these operations.

Whether and how a comment is associated with a node depends on the interpretation of the syntax tree by the manipulating program: Except for Doc and Comment comments directly associated with nodes, the remaining comments are "free-floating" (see also issues #18593, #20744).

type File struct {
		Doc				*CommentGroup	 // associated documentation; or nil
		Package		token.Pos			 // position of "package" keyword
		Name			 *Ident					// package name
		Decls			[]Decl					// top-level declarations; or nil
		Scope			*Scope					// package scope (this file only)
		Imports		[]*ImportSpec	 // imports in this file
		Unresolved []*Ident				// unresolved identifiers in this file
		Comments	 []*CommentGroup // list of all comments in the source file
}

func MergePackageFiles ¶

func MergePackageFiles(pkg *Package, mode MergeMode) *File

MergePackageFiles creates a file AST by merging the ASTs of the files belonging to a package. The mode flags control merging behavior.

func (*File) End ¶

func (f *File) End() token.Pos

func (*File) Pos ¶

func (f *File) Pos() token.Pos

type Filter ¶

type Filter func(string) bool

type ForStmt ¶

A ForStmt represents a for statement.

type ForStmt struct {
		For	token.Pos // position of "for" keyword
		Init Stmt			// initialization statement; or nil
		Cond Expr			// condition; or nil
		Post Stmt			// post iteration statement; or nil
		Body *BlockStmt
}

func (*ForStmt) End ¶

func (s *ForStmt) End() token.Pos

func (*ForStmt) Pos ¶

func (s *ForStmt) Pos() token.Pos

type FuncDecl ¶

A FuncDecl node represents a function declaration.

type FuncDecl struct {
		Doc	*CommentGroup // associated documentation; or nil
		Recv *FieldList		// receiver (methods); or nil (functions)
		Name *Ident				// function/method name
		Type *FuncType		 // function signature: type and value parameters, results, and position of "func" keyword
		Body *BlockStmt		// function body; or nil for external (non-Go) function

}

func (*FuncDecl) End ¶

func (d *FuncDecl) End() token.Pos

func (*FuncDecl) Pos ¶

func (d *FuncDecl) Pos() token.Pos

type FuncLit ¶

A FuncLit node represents a function literal.

type FuncLit struct {
		Type *FuncType	// function type
		Body *BlockStmt // function body
}

func (*FuncLit) End ¶

func (x *FuncLit) End() token.Pos

func (*FuncLit) Pos ¶

func (x *FuncLit) Pos() token.Pos

type FuncType ¶

A FuncType node represents a function type.

type FuncType struct {
		Func		token.Pos	// position of "func" keyword (token.NoPos if there is no "func")
		Params	*FieldList // (incoming) parameters; non-nil
		Results *FieldList // (outgoing) results; or nil
}

func (*FuncType) End ¶

func (x *FuncType) End() token.Pos

func (*FuncType) Pos ¶

func (x *FuncType) Pos() token.Pos

type GenDecl ¶

A GenDecl node (generic declaration node) represents an import, constant, type or variable declaration. A valid Lparen position (Lparen.IsValid()) indicates a parenthesized declaration.

Relationship between Tok value and Specs element type:

token.IMPORT	*ImportSpec
token.CONST	 *ValueSpec
token.TYPE		*TypeSpec
token.VAR		 *ValueSpec

type GenDecl struct {
		Doc		*CommentGroup // associated documentation; or nil
		TokPos token.Pos		 // position of Tok
		Tok		token.Token	 // IMPORT, CONST, TYPE, or VAR
		Lparen token.Pos		 // position of '(', if any
		Specs	[]Spec
		Rparen token.Pos // position of ')', if any
}

func (*GenDecl) End ¶

func (d *GenDecl) End() token.Pos

func (*GenDecl) Pos ¶

func (d *GenDecl) Pos() token.Pos

type GoStmt ¶

A GoStmt node represents a go statement.

type GoStmt struct {
		Go	 token.Pos // position of "go" keyword
		Call *CallExpr
}

func (*GoStmt) End ¶

func (s *GoStmt) End() token.Pos

func (*GoStmt) Pos ¶

func (s *GoStmt) Pos() token.Pos

type Ident ¶

An Ident node represents an identifier.

type Ident struct {
		NamePos token.Pos // identifier position
		Name		string		// identifier name
		Obj		 *Object	 // denoted object; or nil
}

func NewIdent ¶

func NewIdent(name string) *Ident

NewIdent creates a new Ident without position. Useful for ASTs generated by code other than the Go parser.

func (*Ident) End ¶

func (x *Ident) End() token.Pos

func (*Ident) IsExported ¶

func (id *Ident) IsExported() bool

IsExported reports whether id starts with an upper-case letter.

func (*Ident) Pos ¶

func (x *Ident) Pos() token.Pos

func (*Ident) String ¶

func (id *Ident) String() string

type IfStmt ¶

An IfStmt node represents an if statement.

type IfStmt struct {
		If	 token.Pos // position of "if" keyword
		Init Stmt			// initialization statement; or nil
		Cond Expr			// condition
		Body *BlockStmt
		Else Stmt // else branch; or nil
}

func (*IfStmt) End ¶

func (s *IfStmt) End() token.Pos

func (*IfStmt) Pos ¶

func (s *IfStmt) Pos() token.Pos

type ImportSpec ¶

An ImportSpec node represents a single package import.

type ImportSpec struct {
		Doc		 *CommentGroup // associated documentation; or nil
		Name		*Ident				// local package name (including "."); or nil
		Path		*BasicLit		 // import path
		Comment *CommentGroup // line comments; or nil
		EndPos	token.Pos		 // end of spec (overrides Path.Pos if nonzero)
}

func (*ImportSpec) End ¶

func (s *ImportSpec) End() token.Pos

func (*ImportSpec) Pos ¶

func (s *ImportSpec) Pos() token.Pos

type Importer ¶

An Importer resolves import paths to package Objects. The imports map records the packages already imported, indexed by package id (canonical import path). An Importer must determine the canonical import path and check the map to see if it is already present in the imports map. If so, the Importer can return the map entry. Otherwise, the Importer should load the package data for the given path into a new *Object (pkg), record pkg in the imports map, and then return pkg.

type Importer func(imports map[string]*Object, path string) (pkg *Object, err error)

type IncDecStmt ¶

An IncDecStmt node represents an increment or decrement statement.

type IncDecStmt struct {
		X			Expr
		TokPos token.Pos	 // position of Tok
		Tok		token.Token // INC or DEC
}

func (*IncDecStmt) End ¶

func (s *IncDecStmt) End() token.Pos

func (*IncDecStmt) Pos ¶

func (s *IncDecStmt) Pos() token.Pos

type IndexExpr ¶

An IndexExpr node represents an expression followed by an index.

type IndexExpr struct {
		X			Expr			// expression
		Lbrack token.Pos // position of "["
		Index	Expr			// index expression
		Rbrack token.Pos // position of "]"
}

func (*IndexExpr) End ¶

func (x *IndexExpr) End() token.Pos

func (*IndexExpr) Pos ¶

func (x *IndexExpr) Pos() token.Pos

type InterfaceType ¶

An InterfaceType node represents an interface type.

type InterfaceType struct {
		Interface	token.Pos	// position of "interface" keyword
		Methods		*FieldList // list of embedded interfaces, methods, or types
		Incomplete bool			 // true if (source) methods or types are missing in the Methods list
}

func (*InterfaceType) End ¶

func (x *InterfaceType) End() token.Pos

func (*InterfaceType) Pos ¶

func (x *InterfaceType) Pos() token.Pos

type KeyValueExpr ¶

A KeyValueExpr node represents (key : value) pairs in composite literals.

type KeyValueExpr struct {
		Key	 Expr
		Colon token.Pos // position of ":"
		Value Expr
}

func (*KeyValueExpr) End ¶

func (x *KeyValueExpr) End() token.Pos

func (*KeyValueExpr) Pos ¶

func (x *KeyValueExpr) Pos() token.Pos

type LabeledStmt ¶

A LabeledStmt node represents a labeled statement.

type LabeledStmt struct {
		Label *Ident
		Colon token.Pos // position of ":"
		Stmt	Stmt
}

func (*LabeledStmt) End ¶

func (s *LabeledStmt) End() token.Pos

func (*LabeledStmt) Pos ¶

func (s *LabeledStmt) Pos() token.Pos

type MapType ¶

A MapType node represents a map type.

type MapType struct {
		Map	 token.Pos // position of "map" keyword
		Key	 Expr
		Value Expr
}

func (*MapType) End ¶

func (x *MapType) End() token.Pos

func (*MapType) Pos ¶

func (x *MapType) Pos() token.Pos

type MergeMode ¶

The MergeMode flags control the behavior of MergePackageFiles.

type MergeMode uint

const (
		// If set, duplicate function declarations are excluded.
		FilterFuncDuplicates MergeMode = 1 << iota
		// If set, comments that are not associated with a specific
		// AST node (as Doc or Comment) are excluded.
		FilterUnassociatedComments
		// If set, duplicate import declarations are excluded.
		FilterImportDuplicates
)

type Node ¶

All node types implement the Node interface.

type Node interface {
		Pos() token.Pos // position of first character belonging to the node
		End() token.Pos // position of first character immediately after the node
}

type ObjKind ¶

ObjKind describes what an object represents.

type ObjKind int

The list of possible Object kinds.

const (
		Bad ObjKind = iota // for error handling
		Pkg								// package
		Con								// constant
		Typ								// type
		Var								// variable
		Fun								// function or method
		Lbl								// label
)

func (ObjKind) String ¶

func (kind ObjKind) String() string

type Object ¶

An Object describes a named language entity such as a package, constant, type, variable, function (incl. methods), or label.

The Data fields contains object-specific data:

Kind		Data type				 Data value
Pkg		 *Scope						package scope
Con		 int							 iota for the respective declaration

type Object struct {
		Kind ObjKind
		Name string			// declared name
		Decl interface{} // corresponding Field, XxxSpec, FuncDecl, LabeledStmt, AssignStmt, Scope; or nil
		Data interface{} // object-specific data; or nil
		Type interface{} // placeholder for type information; may be nil
}

func NewObj ¶

func NewObj(kind ObjKind, name string) *Object

NewObj creates a new object of a given kind and name.

func (*Object) Pos ¶

func (obj *Object) Pos() token.Pos

Pos computes the source position of the declaration of an object name. The result may be an invalid position if it cannot be computed (obj.Decl may be nil or not correct).

type Package ¶

A Package node represents a set of source files collectively building a Go package.

type Package struct {
		Name		string						 // package name
		Scope	 *Scope						 // package scope across all files
		Imports map[string]*Object // map of package id -> package object
		Files	 map[string]*File	 // Go source files by filename
}

func NewPackage ¶

func NewPackage(fset *token.FileSet, files map[string]*File, importer Importer, universe *Scope) (*Package, error)

NewPackage creates a new Package node from a set of File nodes. It resolves unresolved identifiers across files and updates each file's Unresolved list accordingly. If a non-nil importer and universe scope are provided, they are used to resolve identifiers not declared in any of the package files. Any remaining unresolved identifiers are reported as undeclared. If the files belong to different packages, one package name is selected and files with different package names are reported and then ignored. The result is a package node and a scanner.ErrorList if there were errors.

func (*Package) End ¶

func (p *Package) End() token.Pos

func (*Package) Pos ¶

func (p *Package) Pos() token.Pos

type ParenExpr ¶

A ParenExpr node represents a parenthesized expression.

type ParenExpr struct {
		Lparen token.Pos // position of "("
		X			Expr			// parenthesized expression
		Rparen token.Pos // position of ")"
}

func (*ParenExpr) End ¶

func (x *ParenExpr) End() token.Pos

func (*ParenExpr) Pos ¶

func (x *ParenExpr) Pos() token.Pos

type RangeStmt ¶

A RangeStmt represents a for statement with a range clause.

type RangeStmt struct {
		For				token.Pos	 // position of "for" keyword
		Key, Value Expr				// Key, Value may be nil
		TokPos		 token.Pos	 // position of Tok; invalid if Key == nil
		Tok				token.Token // ILLEGAL if Key == nil, ASSIGN, DEFINE
		X					Expr				// value to range over
		Body			 *BlockStmt
}

func (*RangeStmt) End ¶

func (s *RangeStmt) End() token.Pos

func (*RangeStmt) Pos ¶

func (s *RangeStmt) Pos() token.Pos

type ReturnStmt ¶

A ReturnStmt node represents a return statement.

type ReturnStmt struct {
		Return	token.Pos // position of "return" keyword
		Results []Expr		// result expressions; or nil
}

func (*ReturnStmt) End ¶

func (s *ReturnStmt) End() token.Pos

func (*ReturnStmt) Pos ¶

func (s *ReturnStmt) Pos() token.Pos

type Scope ¶

A Scope maintains the set of named language entities declared in the scope and a link to the immediately surrounding (outer) scope.

type Scope struct {
		Outer	 *Scope
		Objects map[string]*Object
}

func NewScope ¶

func NewScope(outer *Scope) *Scope

NewScope creates a new scope nested in the outer scope.

func (*Scope) Insert ¶

func (s *Scope) Insert(obj *Object) (alt *Object)

Insert attempts to insert a named object obj into the scope s. If the scope already contains an object alt with the same name, Insert leaves the scope unchanged and returns alt. Otherwise it inserts obj and returns nil.

func (*Scope) Lookup ¶

func (s *Scope) Lookup(name string) *Object

Lookup returns the object with the given name if it is found in scope s, otherwise it returns nil. Outer scopes are ignored.

func (*Scope) String ¶

func (s *Scope) String() string

Debugging support

type SelectStmt ¶

A SelectStmt node represents a select statement.

type SelectStmt struct {
		Select token.Pos	// position of "select" keyword
		Body	 *BlockStmt // CommClauses only
}

func (*SelectStmt) End ¶

func (s *SelectStmt) End() token.Pos

func (*SelectStmt) Pos ¶

func (s *SelectStmt) Pos() token.Pos

type SelectorExpr ¶

A SelectorExpr node represents an expression followed by a selector.

type SelectorExpr struct {
		X	 Expr	 // expression
		Sel *Ident // field selector
}

func (*SelectorExpr) End ¶

func (x *SelectorExpr) End() token.Pos

func (*SelectorExpr) Pos ¶

func (x *SelectorExpr) Pos() token.Pos

type SendStmt ¶

A SendStmt node represents a send statement.

type SendStmt struct {
		Chan	Expr
		Arrow token.Pos // position of "<-"
		Value Expr
}

func (*SendStmt) End ¶

func (s *SendStmt) End() token.Pos

func (*SendStmt) Pos ¶

func (s *SendStmt) Pos() token.Pos

type SliceExpr ¶

A SliceExpr node represents an expression followed by slice indices.

type SliceExpr struct {
		X			Expr			// expression
		Lbrack token.Pos // position of "["
		Low		Expr			// begin of slice range; or nil
		High	 Expr			// end of slice range; or nil
		Max		Expr			// maximum capacity of slice; or nil; added in Go 1.2
		Slice3 bool			// true if 3-index slice (2 colons present); added in Go 1.2
		Rbrack token.Pos // position of "]"
}

func (*SliceExpr) End ¶

func (x *SliceExpr) End() token.Pos

func (*SliceExpr) Pos ¶

func (x *SliceExpr) Pos() token.Pos

type Spec ¶

The Spec type stands for any of *ImportSpec, *ValueSpec, and *TypeSpec.

type Spec interface {
		Node
		// contains filtered or unexported methods
}

type StarExpr ¶

A StarExpr node represents an expression of the form "*" Expression. Semantically it could be a unary "*" expression, or a pointer type.

type StarExpr struct {
		Star token.Pos // position of "*"
		X		Expr			// operand
}

func (*StarExpr) End ¶

func (x *StarExpr) End() token.Pos

func (*StarExpr) Pos ¶

func (x *StarExpr) Pos() token.Pos

type Stmt ¶

All statement nodes implement the Stmt interface.

type Stmt interface {
		Node
		// contains filtered or unexported methods
}

type StructType ¶

A StructType node represents a struct type.

type StructType struct {
		Struct		 token.Pos	// position of "struct" keyword
		Fields		 *FieldList // list of field declarations
		Incomplete bool			 // true if (source) fields are missing in the Fields list
}

func (*StructType) End ¶

func (x *StructType) End() token.Pos

func (*StructType) Pos ¶

func (x *StructType) Pos() token.Pos

type SwitchStmt ¶

A SwitchStmt node represents an expression switch statement.

type SwitchStmt struct {
		Switch token.Pos	// position of "switch" keyword
		Init	 Stmt			 // initialization statement; or nil
		Tag		Expr			 // tag expression; or nil
		Body	 *BlockStmt // CaseClauses only
}

func (*SwitchStmt) End ¶

func (s *SwitchStmt) End() token.Pos

func (*SwitchStmt) Pos ¶

func (s *SwitchStmt) Pos() token.Pos

type TypeAssertExpr ¶

A TypeAssertExpr node represents an expression followed by a type assertion.

type TypeAssertExpr struct {
		X			Expr			// expression
		Lparen token.Pos // position of "("; added in Go 1.2
		Type	 Expr			// asserted type; nil means type switch X.(type)
		Rparen token.Pos // position of ")"; added in Go 1.2
}

func (*TypeAssertExpr) End ¶

func (x *TypeAssertExpr) End() token.Pos

func (*TypeAssertExpr) Pos ¶

func (x *TypeAssertExpr) Pos() token.Pos

type TypeSpec ¶

A TypeSpec node represents a type declaration (TypeSpec production).

type TypeSpec struct {
		Doc		 *CommentGroup // associated documentation; or nil
		Name		*Ident				// type name
		Assign	token.Pos		 // position of '=', if any; added in Go 1.9
		Type		Expr					// *Ident, *ParenExpr, *SelectorExpr, *StarExpr, or any of the *XxxTypes
		Comment *CommentGroup // line comments; or nil
}

func (*TypeSpec) End ¶

func (s *TypeSpec) End() token.Pos

func (*TypeSpec) Pos ¶

func (s *TypeSpec) Pos() token.Pos

type TypeSwitchStmt ¶

A TypeSwitchStmt node represents a type switch statement.

type TypeSwitchStmt struct {
		Switch token.Pos	// position of "switch" keyword
		Init	 Stmt			 // initialization statement; or nil
		Assign Stmt			 // x := y.(type) or y.(type)
		Body	 *BlockStmt // CaseClauses only
}

func (*TypeSwitchStmt) End ¶

func (s *TypeSwitchStmt) End() token.Pos

func (*TypeSwitchStmt) Pos ¶

func (s *TypeSwitchStmt) Pos() token.Pos

type UnaryExpr ¶

A UnaryExpr node represents a unary expression. Unary "*" expressions are represented via StarExpr nodes.

type UnaryExpr struct {
		OpPos token.Pos	 // position of Op
		Op		token.Token // operator
		X		 Expr				// operand
}

func (*UnaryExpr) End ¶

func (x *UnaryExpr) End() token.Pos

func (*UnaryExpr) Pos ¶

func (x *UnaryExpr) Pos() token.Pos

type ValueSpec ¶

A ValueSpec node represents a constant or variable declaration (ConstSpec or VarSpec production).

type ValueSpec struct {
		Doc		 *CommentGroup // associated documentation; or nil
		Names	 []*Ident			// value names (len(Names) > 0)
		Type		Expr					// value type; or nil
		Values	[]Expr				// initial values; or nil
		Comment *CommentGroup // line comments; or nil
}

func (*ValueSpec) End ¶

func (s *ValueSpec) End() token.Pos

func (*ValueSpec) Pos ¶

func (s *ValueSpec) Pos() token.Pos

type Visitor ¶

A Visitor's Visit method is invoked for each node encountered by Walk. If the result visitor w is not nil, Walk visits each of the children of node with the visitor w, followed by a call of w.Visit(nil).

type Visitor interface {
		Visit(node Node) (w Visitor)
}