cypher

package module
v0.0.0-...-6d50254 Latest Latest
Warning

This package is not in the latest version of its module.

 Go to latest Published: Jan 3, 2019 License: MIT Imports: 6 Imported by: 0

README

cypher-parser

Cypher Query Language parser in Go.

References

This code is based on https://github.com/influxdata/influxql and modified for the Cypher language.

Documentation

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func ScanBareIdent 

func ScanBareIdent(r io.RuneScanner) string

ScanBareIdent reads bare identifier from a rune reader.

func ScanString 

func ScanString(r io.RuneScanner) (string, error)

ScanString reads a quoted string from a rune reader.

Types

type EdgeDirection 

type EdgeDirection int

EdgeDirection ... 

const (
	EdgeUndefined EdgeDirection = iota
	EdgeRight
	EdgeLeft
	EdgeOutgoing
)

type EdgePattern 

type EdgePattern struct {
	Variable   *string
	Labels     []string
	Properties map[string]Expr
	MinHops    *int
	MaxHops    *int
	Direction  EdgeDirection
}

EdgePattern ...

func (EdgePattern) String 

func (ep EdgePattern) String() string

func (EdgePattern) Var 

func (ep EdgePattern) Var() *string

Var ...

type Expr 

type Expr interface {
	String() string
	// contains filtered or unexported methods
}

Expr ...

type MatchPattern 

type MatchPattern struct {
	Variable *Variable
	Elements []PatternElement
}

MatchPattern ...

func (MatchPattern) String 

func (mp MatchPattern) String() string

type NodePattern 

type NodePattern struct {
	Variable   *Variable
	Labels     []string
	Properties map[string]Expr
}

NodePattern ...

func (NodePattern) String 

func (np NodePattern) String() string

type OrderBy 

type OrderBy struct {
	Dir  OrderDirection
	Item Expr
}

OrderBy ...

func (OrderBy) String 

func (o OrderBy) String() string

type OrderDirection 

type OrderDirection int

OrderDirection ... 

const (
	// Ascending defines the ascending ordering.
	Ascending OrderDirection = iota
	// Descending defines the descending ordering.
	Descending
)

type ParseError 

type ParseError struct {
	Message  string
	Found    string
	Expected []string
	Pos      Pos
}

ParseError represents an error that occurred during parsing.

func (*ParseError) Error 

func (e *ParseError) Error() string

Error returns the string representation of the error.

type Parser 

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

Parser represents a Cypher parser.

func NewParser 

func NewParser(r io.Reader) *Parser

NewParser returns a new instance of Parser.

func (*Parser) ParseQuery 

func (p *Parser) ParseQuery() (q Query, err error)

ParseQuery parses a Cypher string and returns a Query AST object.

func (*Parser) ParseSingleQuery 

func (p *Parser) ParseSingleQuery() (*SingleQuery, error)

ParseSingleQuery ...

func (*Parser) Scan 

func (p *Parser) Scan() (tok Token, pos Pos, lit string)

Scan returns the next token from the underlying scanner.

func (*Parser) ScanEdgePattern 

func (p *Parser) ScanEdgePattern() (*EdgePattern, error)

ScanEdgePattern returns an EdgePattern if possible to consume a complete valid edge.

func (*Parser) ScanExpression 

func (p *Parser) ScanExpression() (Expr, error)

ScanExpression ...

func (*Parser) ScanIgnoreWhitespace 

func (p *Parser) ScanIgnoreWhitespace() (tok Token, pos Pos, lit string)

ScanIgnoreWhitespace scans the next non-whitespace and non-comment token.

func (*Parser) ScanMatchPattern 

func (p *Parser) ScanMatchPattern() (*MatchPattern, error)

ScanMatchPattern ...

func (*Parser) ScanNodePattern 

func (p *Parser) ScanNodePattern() (*NodePattern, error)

ScanNodePattern returns a NodePattern if possible to consume a complete valid node.

func (*Parser) ScanPatternElements 

func (p *Parser) ScanPatternElements() (pe []PatternElement, err error)

ScanPatternElements ...

func (*Parser) ScanProperties 

func (p *Parser) ScanProperties() (*map[string]Expr, error)

ScanProperties ...

func (*Parser) ScanReadingClause 

func (p *Parser) ScanReadingClause() (*ReadingClause, error)

ScanReadingClause ...

func (*Parser) Unscan 

func (p *Parser) Unscan()

Unscan pushes the previously read token back onto the buffer.

type PatternElement 

type PatternElement interface {
	String() string
	// contains filtered or unexported methods
}

PatternElement ...

type Pos 

type Pos struct {
	Line int
	Char int
}

Pos specifies the line and character position of a token. The Char and Line are both zero-based indexes.

type Query 

type Query struct {
	Root *SingleQuery
}

Query represents the Cypher query root element.

func ParseQuery 

func ParseQuery(s string) (Query, error)

ParseQuery parses a query string and returns its AST representation.

func (Query) String 

func (q Query) String() string

type ReadingClause 

type ReadingClause struct {
	OptionalMatch bool
	Pattern       []MatchPattern
	Where         *Expr
}

ReadingClause ...

func (ReadingClause) String 

func (rc ReadingClause) String() string

type Scanner 

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

Scanner is a lexical scanner.

func NewScanner 

func NewScanner(r io.Reader) *Scanner

NewScanner returns a new instance of Scanner.

func (*Scanner) Scan 

func (s *Scanner) Scan() (Token, Pos, string)

Scan returns the next token from the input.

type SingleQuery 

type SingleQuery struct {
	Reading     []ReadingClause
	Distinct    bool
	ReturnItems []Expr
	Order       []OrderBy
	Skip        *Expr
	Limit       *Expr
}

SingleQuery ...

func (SingleQuery) String 

func (sq SingleQuery) String() string

type StrLiteral 

type StrLiteral string

StrLiteral ...

func (StrLiteral) String 

func (s StrLiteral) String() string

type Symbol 

type Symbol string

Symbol ...

func (Symbol) String 

func (s Symbol) String() string

type Token 

type Token int

Token is a lexical token of the Cypher language. 

const (
	// ILLEGAL Token, EOF, WS are Special Cypher tokens.
	ILLEGAL Token = iota
	EOF
	WS
	COMMENT

	// IDENT and the following are literal tokens.
	IDENT     // main
	NUMBER    // 12345.67
	INTEGER   // 12345
	STRING    // "abc"
	BADSTRING // "abc
	BADESCAPE // "\q
	TRUE      // true
	FALSE     // false
	NULL      // null

	PLUS // +
	SUB  // -
	MUL  // *
	DIV  // /
	MOD  // %
	POW  // ^
	EQ   // =
	NEQ  // <>
	LT   // <
	LTE  // <=
	GT   // >
	GTE  // >=
	INC  // +=
	BAR  // |

	AND // AND
	OR  // OR
	XOR // XOR
	NOT // NOT

	LPAREN    // (
	RPAREN    // )
	LBRACE    // {
	RBRACE    // }
	LBRACKET  // [
	RBRACKET  // ]
	COMMA     // ,
	COLON     // :
	SEMICOLON // ;
	DOT       // .
	DOUBLEDOT // ..

	// ALL and the following are Cypher Keywords
	ADD
	ALL
	AS
	ASC
	ASCENDING
	BY
	CASE
	CONSTRAINT
	CONTAINS
	CREATE
	DELETE
	DESC
	DESCENDING
	DETACH
	DISTINCT
	DO
	DROP
	ELSE
	END
	ENDS
	EXISTS
	FOR
	IN
	IS
	LIMIT
	MANDATORY
	MATCH
	MERGE
	OF
	ON
	OPTIONAL
	ORDER
	REMOVE
	REQUIRE
	RETURN
	SCALAR
	SET
	SKIP
	STARTS
	THEN
	UNION
	UNIQUE
	UNWIND
	WHEN
	WHERE
	WITH
)

func Lookup 

func Lookup(ident string) Token

Lookup returns the token associated with a given string.

func (Token) String 

func (tok Token) String() string

String returns the string representation of the token.

type Variable 

type Variable string

Variable ...

func (Variable) String 

func (v Variable) String() string

Source Files

View all Source files

Jump to

Keyboard shortcuts

? : This menu
/ : Search site
f or F : Jump to
y or Y : Canonical URL
go.dev uses cookies from Google to deliver and enhance the quality of its services and to analyze traffic. Learn more.