parser

Documentation

Index

• func ParseEscape(s string) (rune, int, error)
• type Grammar
  • func New(gsource string) (Grammar, error)
• type Node
  • func (n *Node) All(label string) []*Node
  • func (n *Node) Child(label string) *Node
  • func (n *Node) DeepDup() *Node
  • func (n *Node) Dump() string
  • func (n *Node) Dup() *Node
  • func (n *Node) First(label string, start int) *Node
  • func (n *Node) ReconstructContent() (string, error)
  • func (n *Node) String() string
• type NodeStack
  • func (s *NodeStack) Pop() *Node
  • func (s *NodeStack) Push(n *Node)
• type Result
  • func (r *Result) Attach(n *Node)
  • func (r *Result) ComputeContent()
  • func (r *Result) TopNode() *Node

Functions

func ParseEscape

func ParseEscape(s string) (rune, int, error)

ParseEscape parses one C-style escape character from the beginning of string s. It returnes the parsed rune, the number of consumed bytes and error.

Types

type Grammar

type Grammar interface {
	// Parse parses the source text according to the grammar.
	Parse(source string) (*Result, error)
	// Source returns the text source of the grammar description.
	Source() string
}

func New

func New(gsource string) (Grammar, error)

New creates a new grammar.

type Node

type Node struct {
	// Label determines the type of the node, usually corresponding
	// to the rule name (LHS of the parser rule).
	Label string
	// Text is a captured text, if a rule defines a capture region.
	Text string
	// Content is a complete text that was consumed during parsing of this
	// element.  Maybe nil if the content was not recorded during parsing, or for
	// nodes that were programmatically generated.  If not nil, len(Content)
	// should be len(Children) + 1 When present, concatenating node Content in
	// order with children content results in exactly the parser input.
	// NOTE: this is not computed during parsing, but at a later stage.
	Content []string
	// The byte posittion of the first character consumed by this node rule
	// during parsing in the buffer that was passed to parser.
	Pos int
	// The number of bytes consumed by this node rule.
	Len int
	// The line number of the first character consumed by this node. 1-based.
	Row int
	// The column number of the first character consumed by this node. 0-based.
	Col int
	// The children of this node.
	Children []*Node
	// Err caches the error that resulted from application of some parsing rule at some position.
	Err error
	// Annotations stores some string-form annotations.
	Annotations map[string]string
	// TreeAnnotations stores some tree-form annotations (aka labelled children).
	TreeAnnotations map[string]*Node
	// Private fields.
	// Start is used by the bootstrap parser to implement captures. Parser generator or main parser
	// do not need it, but they also set it for compatibility with node drop/keep heuristics.
	// TODO(salikh): Remove after deprecating the bootstrap parser.
	Start int
}

func (*Node) All

func (n *Node) All(label string) []*Node

All returns the slice of node children with the specified label.

func (*Node) Child

func (n *Node) Child(label string) *Node

TODO: rename Child to First

func (*Node) DeepDup

func (n *Node) DeepDup() *Node

DeepDup makes a deep copy of a node.

func (*Node) Dump

func (n *Node) Dump() string

func (*Node) Dup

func (n *Node) Dup() *Node

Dup makes a shallow copy of a node.

func (*Node) First

func (n *Node) First(label string, start int) *Node

First returns the first child with index at least n that has the specified label. If ther is no matching child node, it returns nil.

func (*Node) ReconstructContent

func (n *Node) ReconstructContent() (string, error)

func (*Node) String

func (n *Node) String() string

type NodeStack

type NodeStack []*Node

func (*NodeStack) Pop

func (s *NodeStack) Pop() *Node

func (*NodeStack) Push

func (s *NodeStack) Push(n *Node)

type Result

type Result struct {
	G      *grammar
	Source string
	Memo   map[int]map[*rule]*Node
	Level  int
	// Final AST.
	Tree *Node
	NodeStack
}

Result encapsulates one parse result.

func (*Result) Attach

func (r *Result) Attach(n *Node)

func (*Result) ComputeContent

func (r *Result) ComputeContent()

ComputeContent annotates the parse tree with pieces of original content and line/column positions in the original parser input.

func (*Result) TopNode

func (r *Result) TopNode() *Node