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 Go to latest Published: Jun 24, 2024 License: MIT Imports: 4 Imported by: 0

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Constants

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const (
	KeywordLimit  = "limit"
	KeywordOffset = "offset"
	KeywordOrder  = "order"
)

Variables

This section is empty.

Functions

func AreAllExpressions 

func AreAllExpressions(e []Expression, fn func(Expression) bool) bool

AreAllExpressions returns true if all expressions satisfy a function.

func AsIntegerLiteral 

func AsIntegerLiteral(expr Expression) (int, bool)

func AsStringLiteral 

func AsStringLiteral(expr Expression) (string, bool)

func AttributeAliasFromExpr 

func AttributeAliasFromExpr(expr Expression) (string, bool)

AttributeAliasFromExpr will return "bar" for "bar" or "foo.bar". Returns false if the expression includes anything else, such as parent references or array subscripting.

func Contains 

func Contains(expr Expression, visitor func(Expression) bool) bool

Contains is like Walk(), except its return value is the reverse: If the walk visitor returns true, walking is aborted, and the function returns true.

func HasArrayTraversal 

func HasArrayTraversal(expr Expression) bool

func InterfaceFromLiteral 

func InterfaceFromLiteral(expr interface{}) interface{}

InterfaceFromLiteral returns a value from a Literal interface. Returns nil if the expression is not a literal.

func IsArithmeticOperator 

func IsArithmeticOperator(token Token) bool

IsArithmeticOperator checks whether an operator is an arithmetic operator.

func IsAttribute 

func IsAttribute(e Expression) bool

func IsFalse 

func IsFalse(expr Expression) bool

func IsLiteral 

func IsLiteral(e Expression) bool

func IsSubscriptExpression 

func IsSubscriptExpression(e Expression) bool

IsSubscriptExpression checks whether an expression is a valid subscript expression. Since subscripts and filters share the same syntax, we limit subscripts to only contain numeric literals and the arithmetic operators.

func IsTrue 

func IsTrue(expr Expression) bool

func ValidateParentAccess 

func ValidateParentAccess(expr Expression) error

func Walk 

func Walk(expr Expression, visitor func(Expression) bool) bool

Walk walks an expression top-down, i.e. the outer struct first. If the visitor returns false, the walking is halted.

Types

type Array 

type Array struct {
	Pos         Position
	Expressions []Expression
}

Array is a an array on the form `[a, b, 1, 2, 3]`

func (*Array) Equal 

func (e *Array) Equal(b Expression) bool

func (*Array) GetPos 

func (e *Array) GetPos() Position

func (*Array) MarshalJSON 

func (expr *Array) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*Array) Transform 

func (e *Array) Transform(f TransformFunc) Expression

type ArrayTraversal 

type ArrayTraversal struct {
	Pos Position

	// Expr is NOT used by the old engine, where it is combined with a PipeOperator.
	Expr Expression
}

ArrayTraversal marks the expression for array traversal.

func (*ArrayTraversal) Equal 

func (e *ArrayTraversal) Equal(b Expression) bool

func (*ArrayTraversal) GetPos 

func (e *ArrayTraversal) GetPos() Position

func (*ArrayTraversal) MarshalJSON 

func (e *ArrayTraversal) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*ArrayTraversal) Transform 

func (e *ArrayTraversal) Transform(f TransformFunc) Expression

type Attribute 

type Attribute struct {
	Pos  Position
	Name string
}

Attribute represents specification of a field on the form `title` as in `book.title`

func AsAttribute 

func AsAttribute(expr Expression) (*Attribute, bool)

func (*Attribute) Equal 

func (e *Attribute) Equal(b Expression) bool

func (*Attribute) GetPos 

func (e *Attribute) GetPos() Position

func (*Attribute) MarshalJSON 

func (e *Attribute) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*Attribute) Transform 

func (e *Attribute) Transform(f TransformFunc) Expression

type BinaryOperator 

type BinaryOperator struct {
	Pos      Position
	LHS      Expression
	RHS      Expression
	Operator Token
}

BinaryOperator represents two expressions joint with an operator

func (*BinaryOperator) Equal 

func (e *BinaryOperator) Equal(b Expression) bool

func (*BinaryOperator) GetPos 

func (e *BinaryOperator) GetPos() Position

func (*BinaryOperator) MarshalJSON 

func (expr *BinaryOperator) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*BinaryOperator) Transform 

func (e *BinaryOperator) Transform(f TransformFunc) Expression

type BooleanLiteral 

type BooleanLiteral struct {
	Pos   Position
	Value bool
}

BooleanLiteral is a literal bool

func (*BooleanLiteral) Equal 

func (e *BooleanLiteral) Equal(b Expression) bool

func (*BooleanLiteral) GetPos 

func (e *BooleanLiteral) GetPos() Position

func (*BooleanLiteral) LiteralValue 

func (e *BooleanLiteral) LiteralValue() interface{}

LiteralValue implements Literal.

func (*BooleanLiteral) MarshalJSON 

func (expr *BooleanLiteral) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*BooleanLiteral) Transform 

func (e *BooleanLiteral) Transform(f TransformFunc) Expression

type Constraint 

type Constraint struct {
	Pos        Position
	Expression Expression
}

A Constraint operation, on the form `*[is "article" && expiresAt < $now && _createdAt desc]`

func (*Constraint) Equal 

func (e *Constraint) Equal(b Expression) bool

func (*Constraint) GetPos 

func (e *Constraint) GetPos() Position

func (*Constraint) MarshalJSON 

func (e *Constraint) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*Constraint) Transform 

func (e *Constraint) Transform(f TransformFunc) Expression

type DotOperator 

type DotOperator struct {
	Pos Position
	LHS Expression
	RHS Expression
}

DotOperator is a convenience class for the common operator '.'

func (*DotOperator) Equal 

func (e *DotOperator) Equal(b Expression) bool

func (*DotOperator) GetPos 

func (e *DotOperator) GetPos() Position

func (*DotOperator) MarshalJSON 

func (e *DotOperator) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*DotOperator) Transform 

func (e *DotOperator) Transform(f TransformFunc) Expression

type Element 

type Element struct {
	Pos Position
	LHS Expression
	Idx *Subscript
}

Element returns an indexed element of an array.

func (*Element) Equal 

func (e *Element) Equal(b Expression) bool

func (*Element) GetPos 

func (e *Element) GetPos() Position

func (*Element) Transform 

func (e *Element) Transform(f TransformFunc) Expression

type Ellipsis 

type Ellipsis struct {
	Pos Position
}

Ellipsis represents a '...'-statement

func (*Ellipsis) Equal 

func (*Ellipsis) Equal(b Expression) bool

func (*Ellipsis) GetPos 

func (e *Ellipsis) GetPos() Position

func (*Ellipsis) MarshalJSON 

func (*Ellipsis) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*Ellipsis) Transform 

func (e *Ellipsis) Transform(f TransformFunc) Expression

type Everything 

type Everything struct {
	Pos Position
}

Everything is the `*`, the root of all queries

func (*Everything) Equal 

func (*Everything) Equal(b Expression) bool

func (*Everything) GetPos 

func (e *Everything) GetPos() Position

func (*Everything) MarshalJSON 

func (*Everything) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*Everything) Transform 

func (e *Everything) Transform(f TransformFunc) Expression

type Expression 

type Expression interface {
	GetPos() Position
	Transform(TransformFunc) Expression
	Equal(Expression) bool
	// contains filtered or unexported methods
}

Expression is the common interface for all GROQ expressions

func CombineAnd 

func CombineAnd(lhs, rhs Expression) Expression

func CombineOr 

func CombineOr(lhs, rhs Expression) Expression

func LiteralFromInterface 

func LiteralFromInterface(value interface{}, pos Position) (Expression, error)

LiteralFromInterface takes a value and returns a value wrapped in a Literal interface.

func Transform 

func Transform(expr Expression, f TransformFunc) Expression

Transform walks an expression depth-first.

type Filter 

type Filter struct {
	Pos        Position
	LHS        Expression
	Constraint *Constraint
}

A Filter filters an array using another expression.

func (*Filter) Equal 

func (e *Filter) Equal(b Expression) bool

func (*Filter) GetPos 

func (e *Filter) GetPos() Position

func (*Filter) Transform 

func (e *Filter) Transform(f TransformFunc) Expression

type FloatLiteral 

type FloatLiteral struct {
	Pos   Position
	Value float64
}

FloatLiteral is literal float

func (*FloatLiteral) Equal 

func (e *FloatLiteral) Equal(b Expression) bool

func (*FloatLiteral) GetPos 

func (e *FloatLiteral) GetPos() Position

func (*FloatLiteral) LiteralValue 

func (e *FloatLiteral) LiteralValue() interface{}

LiteralValue implements Literal.

func (*FloatLiteral) MarshalJSON 

func (expr *FloatLiteral) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*FloatLiteral) Transform 

func (e *FloatLiteral) Transform(f TransformFunc) Expression

type FunctionCall 

type FunctionCall struct {
	Namespace string
	Pos       Position
	Name      string
	Arguments []Expression
}

FunctionCall represents a function invocation on the form function(expression). Namespace represents namespaced function call like string::length()

func (*FunctionCall) Equal 

func (e *FunctionCall) Equal(b Expression) bool

func (*FunctionCall) GetPos 

func (e *FunctionCall) GetPos() Position

func (*FunctionCall) MarshalJSON 

func (expr *FunctionCall) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*FunctionCall) Transform 

func (e *FunctionCall) Transform(f TransformFunc) Expression

type FunctionDefinition 

type FunctionDefinition struct {
	Pos        Position
	ID         FunctionID
	Body       Expression
	Parameters []*FunctionParamDefinition
}

func (*FunctionDefinition) GetID 

func (fd *FunctionDefinition) GetID() FunctionID

type FunctionID 

type FunctionID struct {
	Namespace string
	Name      string
}

func (FunctionID) String 

func (id FunctionID) String() string

type FunctionParam 

type FunctionParam struct {
	Definition *FunctionParamDefinition
	Pos        Position
}

func (FunctionParam) Equal 

func (fp FunctionParam) Equal(e Expression) bool

func (FunctionParam) GetPos 

func (fp FunctionParam) GetPos() Position

func (FunctionParam) Transform 

func (fp FunctionParam) Transform(f TransformFunc) Expression

type FunctionParamDefinition 

type FunctionParamDefinition struct {
	Index int
	Name  string
}

type FunctionPipe 

type FunctionPipe struct {
	Pos  Position
	LHS  Expression
	Func *FunctionCall
}

A FunctionPipe maps an object or array of objects through a function.

func (*FunctionPipe) Equal 

func (e *FunctionPipe) Equal(b Expression) bool

func (*FunctionPipe) GetPos 

func (e *FunctionPipe) GetPos() Position

func (*FunctionPipe) Transform 

func (e *FunctionPipe) Transform(f TransformFunc) Expression

type Group 

type Group struct {
	Pos        Position
	Expression Expression
}

Group is a node inserted around an expression to indicate places where explicit parentheses have special meaning.

It is currently only used to stop array traversal, i.e. to indicate that an expression should not be folded over by subsequent expressions.

For example, while a[][0] means "the first element of each a", (a[])[0] means "the first element of a". Rather than resolving this in the parser, we wrap the left side in a group node.

func (*Group) Equal 

func (e *Group) Equal(b Expression) bool

func (*Group) GetPos 

func (e *Group) GetPos() Position

func (*Group) MarshalJSON 

func (expr *Group) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*Group) Transform 

func (e *Group) Transform(f TransformFunc) Expression

type IntegerLiteral 

type IntegerLiteral struct {
	Pos   Position
	Value int
}

IntegerLiteral is literal integer

func (*IntegerLiteral) Equal 

func (e *IntegerLiteral) Equal(b Expression) bool

func (*IntegerLiteral) GetPos 

func (e *IntegerLiteral) GetPos() Position

func (*IntegerLiteral) LiteralValue 

func (e *IntegerLiteral) LiteralValue() interface{}

LiteralValue implements Literal.

func (*IntegerLiteral) MarshalJSON 

func (expr *IntegerLiteral) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*IntegerLiteral) Transform 

func (e *IntegerLiteral) Transform(f TransformFunc) Expression

type Literal 

type Literal interface {
	LiteralValue() interface{}
}

Literal is the common interface implemented by all literal nodes

type NullLiteral 

type NullLiteral struct {
	Pos Position
}

NullLiteral is a literal null

func (*NullLiteral) Equal 

func (e *NullLiteral) Equal(b Expression) bool

func (*NullLiteral) GetPos 

func (e *NullLiteral) GetPos() Position

func (*NullLiteral) LiteralValue 

func (e *NullLiteral) LiteralValue() interface{}

LiteralValue implements Literal.

func (*NullLiteral) MarshalJSON 

func (expr *NullLiteral) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*NullLiteral) Transform 

func (e *NullLiteral) Transform(f TransformFunc) Expression

type Object 

type Object struct {
	Pos         Position
	Expressions []Expression
}

Object is a `{title, body, somethingsomething}`

func (*Object) Equal 

func (e *Object) Equal(b Expression) bool

func (*Object) GetPos 

func (e *Object) GetPos() Position

func (*Object) MarshalJSON 

func (expr *Object) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*Object) Transform 

func (e *Object) Transform(f TransformFunc) Expression

type Param 

type Param struct {
	Pos  Position
	Name string
}

Param represents a placeholder parameter, e.g. $foo.

func (*Param) Equal 

func (e *Param) Equal(b Expression) bool

func (*Param) GetPos 

func (e *Param) GetPos() Position

func (*Param) Transform 

func (e *Param) Transform(f TransformFunc) Expression

type Parent 

type Parent struct {
	Pos Position
}

Parent is the `^`, the item being processed in a mapping operation

func (*Parent) Equal 

func (*Parent) Equal(b Expression) bool

func (*Parent) GetPos 

func (e *Parent) GetPos() Position

func (*Parent) MarshalJSON 

func (*Parent) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*Parent) Transform 

func (e *Parent) Transform(f TransformFunc) Expression

type ParseError 

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

ParseError represents an error during parsing

func NewParseError 

func NewParseError(msg string, pos Position) *ParseError

func (*ParseError) Error 

func (e *ParseError) Error() string

func (*ParseError) Message 

func (e *ParseError) Message() string

func (*ParseError) Pos 

func (e *ParseError) Pos() Position

type PipeOperator 

type PipeOperator struct {
	Pos Position
	LHS Expression
	RHS Expression
}

PipeOperator is a convenience class for the very common operator '|'

func (*PipeOperator) Equal 

func (e *PipeOperator) Equal(b Expression) bool

func (*PipeOperator) GetPos 

func (e *PipeOperator) GetPos() Position

func (*PipeOperator) MarshalJSON 

func (expr *PipeOperator) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*PipeOperator) Transform 

func (e *PipeOperator) Transform(f TransformFunc) Expression

type Position 

type Position struct {
	Start  int
	End    int
	Source string
}

Position represents a position in the source code

type PostfixOperator 

type PostfixOperator struct {
	Pos      Position
	LHS      Expression
	Operator Token
}

PostfixOperator represents an expression followed by an operator `_createdAt desc`

func (*PostfixOperator) Equal 

func (e *PostfixOperator) Equal(b Expression) bool

func (*PostfixOperator) GetPos 

func (e *PostfixOperator) GetPos() Position

func (*PostfixOperator) MarshalJSON 

func (expr *PostfixOperator) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*PostfixOperator) Transform 

func (e *PostfixOperator) Transform(f TransformFunc) Expression

type PrefixOperator 

type PrefixOperator struct {
	Pos      Position
	RHS      Expression
	Operator Token
}

PrefixOperator represents a prefix operator `!completed`

func (*PrefixOperator) Equal 

func (e *PrefixOperator) Equal(b Expression) bool

func (*PrefixOperator) GetPos 

func (e *PrefixOperator) GetPos() Position

func (*PrefixOperator) MarshalJSON 

func (expr *PrefixOperator) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*PrefixOperator) Transform 

func (e *PrefixOperator) Transform(f TransformFunc) Expression

type Projection 

type Projection struct {
	Pos    Position
	LHS    Expression
	Object *Object
}

A Projection maps an object or array of objects to a new object.

func (*Projection) Equal 

func (e *Projection) Equal(b Expression) bool

func (*Projection) GetPos 

func (e *Projection) GetPos() Position

func (*Projection) Transform 

func (e *Projection) Transform(f TransformFunc) Expression

type Range 

type Range struct {
	Pos       Position
	Start     Expression
	End       Expression
	Inclusive bool
}

Range is a literal range expression on the form `[1..10]` (inclusive), `[1...10]` (exclusive)

func (*Range) Equal 

func (e *Range) Equal(b Expression) bool

func (*Range) GetPos 

func (e *Range) GetPos() Position

func (*Range) MarshalJSON 

func (expr *Range) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*Range) Transform 

func (e *Range) Transform(f TransformFunc) Expression

type Slice 

type Slice struct {
	Pos   Position
	LHS   Expression
	Range *Subscript
}

Slice retrieves a range of an array.

func (*Slice) Equal 

func (e *Slice) Equal(b Expression) bool

func (*Slice) GetPos 

func (e *Slice) GetPos() Position

func (*Slice) Transform 

func (e *Slice) Transform(f TransformFunc) Expression

type StringLiteral 

type StringLiteral struct {
	Pos   Position
	Value string
}

StringLiteral is literal strings

func (*StringLiteral) Equal 

func (e *StringLiteral) Equal(b Expression) bool

func (*StringLiteral) GetPos 

func (e *StringLiteral) GetPos() Position

func (*StringLiteral) LiteralValue 

func (e *StringLiteral) LiteralValue() interface{}

LiteralValue implements Literal.

func (*StringLiteral) MarshalJSON 

func (e *StringLiteral) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*StringLiteral) Transform 

func (e *StringLiteral) Transform(f TransformFunc) Expression

type Subscript 

type Subscript struct {
	Pos   Position
	Value Expression
}

Subscript is on the form `[0]`

func (*Subscript) Equal 

func (e *Subscript) Equal(b Expression) bool

func (*Subscript) GetPos 

func (e *Subscript) GetPos() Position

func (*Subscript) MarshalJSON 

func (expr *Subscript) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (*Subscript) Transform 

func (e *Subscript) Transform(f TransformFunc) Expression

type This 

type This struct {
	Pos Position
}

This `@` is the current root value of the scope

func (*This) Equal 

func (*This) Equal(b Expression) bool

func (*This) GetPos 

func (e *This) GetPos() Position

func (*This) Transform 

func (e *This) Transform(f TransformFunc) Expression

type Token 

type Token int

Token represents one token 

const (
	Illegal        Token = iota
	EOF                  // End of File
	Whitespace           // A contiguous sequence of white space
	ParenLeft            // (
	ParenRight           // )
	BraceLeft            // {
	BraceRight           // }
	BracketLeft          // [
	BracketRight         // ]
	Dot                  // .
	Equals               // ==
	Or                   // ||
	And                  // &&
	GT                   // >
	LT                   // <
	GTE                  // >=
	LTE                  // <=
	NEQ                  // !=
	Not                  // !
	Null                 // null
	Arrow                // ->
	At                   // @
	Comma                // ,
	Colon                // :
	Name                 // A valid field or type identifier
	DotDot               // ..
	DotDotDot            // ...
	MatchOperator        // match
	InOperator           // in
	AscOperator          // asc
	DescOperator         // desc
	Integer              // 1234
	Float                // 123.4
	Bool                 // true or false
	String               // 'literal string' or "literal string"
	Hat                  // ^
	Asterisk             // *
	Exponentiation       // **
	Slash                // /
	Percent              // %
	Plus                 // +
	Minus                // -
	Pipe                 // |
	Rocket               // =>
	DoubleColon          // ::
	TokenMax             // Always last
	EqualSign            // =
	Semicolon            // ;
)

The different tokens

func InvertOperator 

func InvertOperator(operator Token) Token

func MatchingBrace 

func MatchingBrace(token Token) Token

MatchingBrace returns the brace matching the provided token, as in '(' returns ')' and '[' returns ']'

func (Token) Literal 

func (token Token) Literal() string

Literal converts a token id to a literal where applicable

func (Token) MarshalJSON 

func (token Token) MarshalJSON() ([]byte, error)

MarshalJSON marshals an AST node to JSON.

func (Token) String 

func (token Token) String() string

type TransformFunc 

type TransformFunc func(Expression) Expression

type Tuple 

type Tuple struct {
	Pos     Position
	Members []Expression
}

Tuple represents parenthesized expression: (foo, bar)

func (*Tuple) Equal 

func (e *Tuple) Equal(b Expression) bool

func (*Tuple) GetPos 

func (e *Tuple) GetPos() Position

func (*Tuple) Transform 

func (e *Tuple) Transform(f TransformFunc) Expression

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