extend

Documentation

Overview

The extend package contains features for operating on and extending syntax trees.

Index

• type FileScope
  • func BuildFileScope(file *tree.File) *FileScope
• type Scope
  • func NewScope(parent *Scope, node tree.Node) *Scope
• type Variable
  • func (v *Variable) VisiblityOverlapsWith(w *Variable) bool
• type VariableType
  • func (t VariableType) String() string

Types

type FileScope

type FileScope struct {
	// Root is the root scope.
	Root *Scope
	// Globals is a list of global variables that have been assigned to.
	Globals []*Variable
	// VariableMap maps a NAME token to a Variable.
	VariableMap map[*tree.Token]*Variable
	// ScopeMap maps a Node to the scope that is opened by or is otherwise
	// associated with the node.
	ScopeMap map[tree.Node]*Scope
}

FileScope contains information about the scopes of a file, including variables and their associations with a parse tree.

func BuildFileScope

func BuildFileScope(file *tree.File) *FileScope

BuildFileScope walks the given parse tree, building a tree of scopes and the variables they contain.

type Scope

type Scope struct {
	// Parent is the outer, surrounding scope.
	Parent *Scope
	// Children is a list of inner scopes.
	Children []*Scope
	// Variables is the list of variables declared in the scope.
	Variables []*Variable
	// Node is the tree node that opens or is otherwise associated with the
	// scope. May be nil.
	Node tree.Node
	// Items is a list of NAME tokens and Scopes, ordered semantically.
	Items []interface{}
	// Start indicates the start of the lifetime of the scope. The value has no
	// objective meaning, and should be used only for comparing with other
	// lifetimes within the same generated FileScope.
	Start int
	// End indicates the end of the lifetime of the scope. The value has no
	// objective meaning, and should be used only for comparing with other
	// lifetimes within the same generated FileScope.
	End int
}

Scope contains a list of the variables declared in the scope.

func NewScope

func NewScope(parent *Scope, node tree.Node) *Scope

NewScope creates an inner scope, optionally associating the scope with the node that opens it.

type Variable

type Variable struct {
	// Type is the variable type.
	Type VariableType
	// Name is the name of the variable.
	Name string
	// References is a list of NAME tokens that refer to the entity. When the
	// variable is local, the first value is the declaration of the variable.
	References []*tree.Token
	// Scopes is a list of scopes corresponding to entries in References.
	Scopes []*Scope
	// Positions is a list of positions corresponding to entries in References.
	Positions []int
	// LifeStart indicates the start of the lifetime and visiblity of the
	// variable. The value has no objective meaning, and should be used only for
	// comparing with other lifetimes within the same generated FileScope.
	LifeStart int
	// LifeEnd indicates the end of the lifetime of the variable. The value has
	// no objective meaning, and should be used only for comparing with other
	// lifetimes within the same generated FileScope.
	LifeEnd int
	// ScopeEnd indicates the end of the visibility of the variable. The value
	// has no objective meaning, and should be used only for comparing with
	// other lifetimes within the same generated FileScope.
	ScopeEnd int
}

Variable describes a single named entity within a parse tree.

func (*Variable) VisiblityOverlapsWith

func (v *Variable) VisiblityOverlapsWith(w *Variable) bool

VisiblityOverlapsWith returns whether the visiblity of v overlaps with the visiblity of w.

type VariableType

type VariableType uint8

VariableType indicates the type of Variable.

const (
	InvalidVar VariableType = iota

	LocalVar  // LocalVar indicates a variable local to its scope.
	GlobalVar // GlobalVar indicates a variable defined in the global table.
)

func (VariableType) String

func (t VariableType) String() string