ast

Documentation

Overview

Package ast provides the parser for WDTE.

Index

• type Epsilon
  • func (e Epsilon) Children() []Node
  • func (e Epsilon) Parent() Node
• type NTerm
  • func (nt *NTerm) AddChild(n Node)
  • func (nt NTerm) Children() []Node
  • func (nt NTerm) Name() string
  • func (nt NTerm) Parent() Node
• type Node
  • func Parse(r io.Reader, macros scanner.MacroMap) (Node, error)
• type ParseError
  • func (err ParseError) Error() string
• type Term
  • func (t Term) Children() []Node
  • func (t Term) Parent() Node
  • func (t Term) Tok() scanner.Token

Types

type Epsilon

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

An Epsilon is a special terminal which represnts a non-action.

func (Epsilon) Children

func (e Epsilon) Children() []Node

func (Epsilon) Parent

func (e Epsilon) Parent() Node

type NTerm

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

An NTerm is a Node that represents a non-terminal. NTerms are always parent nodes.

func (*NTerm) AddChild

func (nt *NTerm) AddChild(n Node)

AddChild adds a child to the right-hand side of the NTerm's list of children.

func (NTerm) Children

func (nt NTerm) Children() []Node

func (NTerm) Name

func (nt NTerm) Name() string

Name returns the name of the non-terminal, minus the surrounding `<` and `>`.

func (NTerm) Parent

func (nt NTerm) Parent() Node

type Node

type Node interface {
	// Parent returns the Node's parent, or nil if it is the root node.
	Parent() Node

	// Children returns the node's children in left-to-right order.
	Children() []Node
}

A Node represents a node of the AST.

func Parse

func Parse(r io.Reader, macros scanner.MacroMap) (Node, error)

Parse parses a full script, returning the root node of the AST.

type ParseError

type ParseError struct {
	Line, Col int
	Err       error
}

A ParseError is returned if an error happens during parsing.

func (ParseError) Error

func (err ParseError) Error() string

type Term

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

A Term is a Node that represents a terminal, such as a string or a keyword. Terms are always leaf nodes.

func (Term) Children

func (t Term) Children() []Node

func (Term) Parent

func (t Term) Parent() Node

func (Term) Tok

func (t Term) Tok() scanner.Token

Tok returns the scanner token that the node was generated from.