expr

package
v0.2.0 Latest Latest
Warning

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

 Go to latest Published: May 24, 2021 License: MIT Imports: 7 Imported by: 0

Documentation

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func Between 

func Between(a Expr) func(x, b Expr) Expr

Between returns a function that creates a BETWEEN operator that returns true if x is between a and b.

func BuiltinFunctions 

func BuiltinFunctions() map[string]func(args ...Expr) (Expr, error)

BuiltinFunctions returns default map of builtin functions.

func Equal 

func Equal(a, b Expr) bool

Equal reports whether a and b are equal by first calling IsEqual if they have an IsEqual method with this signature: 

IsEqual(Expr) bool

If not, it returns whether a and b values are equal.

func IsArithmeticOperator 

func IsArithmeticOperator(op Operator) bool

IsArithmeticOperator returns true if e is one of +, -, *, /, %, &, |, or ^ operators.

func IsComparisonOperator 

func IsComparisonOperator(op Operator) bool

IsComparisonOperator returns true if e is one of =, !=, >, >=, <, <=, IS, IS NOT, IN, or NOT IN operators.

func OperatorIsIndexCompatible 

func OperatorIsIndexCompatible(op Operator) bool

OperatorIsIndexCompatible returns whether the operator can be used to read from an index.

func Walk 

func Walk(e Expr, fn func(Expr) bool) bool

Types

type Aggregator 

type Aggregator interface {
	Expr

	Aggregate(env *Environment) error
}

A Aggregator is an expression that aggregates documents into one result.

type AggregatorBuilder 

type AggregatorBuilder interface {
	Aggregator() Aggregator
}

An AggregatorBuilder is a type that can create aggregators.

type AndOp 

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

AndOp is the And operator.

func (*AndOp) Eval 

func (op *AndOp) Eval(env *Environment) (document.Value, error)

Eval implements the Expr interface. It evaluates a and b and returns true if both evaluate to true.

func (AndOp) IsEqual 

func (op AndOp) IsEqual(other Expr) bool

Equal compares this expression with the other expression and returns true if they are equal.

func (AndOp) LeftHand 

func (op AndOp) LeftHand() Expr

func (AndOp) Precedence 

func (op AndOp) Precedence() int

func (AndOp) RightHand 

func (op AndOp) RightHand() Expr

func (AndOp) SetLeftHandExpr 

func (op AndOp) SetLeftHandExpr(a Expr)

func (AndOp) SetRightHandExpr 

func (op AndOp) SetRightHandExpr(b Expr)

func (AndOp) String 

func (op AndOp) String() string

func (AndOp) Token 

func (op AndOp) Token() scanner.Token

type AvgAggregator 

type AvgAggregator struct {
	Fn      *AvgFunc
	Avg     float64
	Counter int64
}

AvgAggregator is an aggregator that returns the average non-null value.

func (*AvgAggregator) Aggregate 

func (s *AvgAggregator) Aggregate(env *Environment) error

Aggregate stores the average value of all non-NULL numeric values in the group.

func (*AvgAggregator) Eval 

func (s *AvgAggregator) Eval(env *Environment) (document.Value, error)

Eval returns the aggregated average as a double.

func (*AvgAggregator) String 

func (s *AvgAggregator) String() string

type AvgFunc 

type AvgFunc struct {
	Expr Expr
}

AvgFunc is the AVG aggregator function.

func (*AvgFunc) Aggregator 

func (s *AvgFunc) Aggregator() Aggregator

Aggregator returns a AvgFunc. It implements the AggregatorBuilder interface.

func (*AvgFunc) Eval 

func (s *AvgFunc) Eval(env *Environment) (document.Value, error)

Eval extracts the average value from the given document and returns it.

func (*AvgFunc) IsEqual 

func (s *AvgFunc) IsEqual(other Expr) bool

IsEqual compares this expression with the other expression and returns true if they are equal.

func (*AvgFunc) Params 

func (s *AvgFunc) Params() []Expr

func (*AvgFunc) String 

func (s *AvgFunc) String() string

String returns the alias if non-zero, otherwise it returns a string representation of the average expression.

type BetweenOperator 

type BetweenOperator struct {
	X Expr
	// contains filtered or unexported fields
}

func (*BetweenOperator) Eval 

func (op *BetweenOperator) Eval(env *Environment) (document.Value, error)

func (BetweenOperator) IsEqual 

func (op BetweenOperator) IsEqual(other Expr) bool

Equal compares this expression with the other expression and returns true if they are equal.

func (BetweenOperator) LeftHand 

func (op BetweenOperator) LeftHand() Expr

func (BetweenOperator) Precedence 

func (op BetweenOperator) Precedence() int

func (BetweenOperator) RightHand 

func (op BetweenOperator) RightHand() Expr

func (BetweenOperator) SetLeftHandExpr 

func (op BetweenOperator) SetLeftHandExpr(a Expr)

func (BetweenOperator) SetRightHandExpr 

func (op BetweenOperator) SetRightHandExpr(b Expr)

func (*BetweenOperator) String 

func (op *BetweenOperator) String() string

func (BetweenOperator) Token 

func (op BetweenOperator) Token() scanner.Token

type CastFunc 

type CastFunc struct {
	Expr   Expr
	CastAs document.ValueType
}

CastFunc represents the CAST expression.

func (CastFunc) Eval 

func (c CastFunc) Eval(env *Environment) (document.Value, error)

Eval returns the primary key of the current document.

func (CastFunc) IsEqual 

func (c CastFunc) IsEqual(other Expr) bool

IsEqual compares this expression with the other expression and returns true if they are equal.

func (CastFunc) Params 

func (c CastFunc) Params() []Expr

func (CastFunc) String 

func (c CastFunc) String() string

type ConcatOperator 

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

func (*ConcatOperator) Eval 

func (op *ConcatOperator) Eval(env *Environment) (document.Value, error)

func (ConcatOperator) IsEqual 

func (op ConcatOperator) IsEqual(other Expr) bool

Equal compares this expression with the other expression and returns true if they are equal.

func (ConcatOperator) LeftHand 

func (op ConcatOperator) LeftHand() Expr

func (ConcatOperator) Precedence 

func (op ConcatOperator) Precedence() int

func (ConcatOperator) RightHand 

func (op ConcatOperator) RightHand() Expr

func (ConcatOperator) SetLeftHandExpr 

func (op ConcatOperator) SetLeftHandExpr(a Expr)

func (ConcatOperator) SetRightHandExpr 

func (op ConcatOperator) SetRightHandExpr(b Expr)

func (ConcatOperator) String 

func (op ConcatOperator) String() string

func (ConcatOperator) Token 

func (op ConcatOperator) Token() scanner.Token

type CountAggregator 

type CountAggregator struct {
	Fn    *CountFunc
	Count int64
}

CountAggregator is an aggregator that counts non-null expressions.

func (*CountAggregator) Aggregate 

func (c *CountAggregator) Aggregate(env *Environment) error

Aggregate increments the counter if the count expression evaluates to a non-null value.

func (*CountAggregator) Eval 

func (c *CountAggregator) Eval(env *Environment) (document.Value, error)

Eval returns the result of the aggregation as an integer.

func (*CountAggregator) String 

func (c *CountAggregator) String() string

type CountFunc 

type CountFunc struct {
	Expr     Expr
	Wildcard bool
	Count    int64
}

CountFunc is the COUNT aggregator function. It counts the number of documents in a stream.

func (*CountFunc) Aggregator 

func (c *CountFunc) Aggregator() Aggregator

Aggregator returns a CountAggregator. It implements the AggregatorBuilder interface.

func (*CountFunc) Eval 

func (c *CountFunc) Eval(env *Environment) (document.Value, error)

func (*CountFunc) IsEqual 

func (c *CountFunc) IsEqual(other Expr) bool

IsEqual compares this expression with the other expression and returns true if they are equal.

func (*CountFunc) Params 

func (c *CountFunc) Params() []Expr

func (*CountFunc) String 

func (c *CountFunc) String() string

type Environment 

type Environment struct {
	Params []Param
	Vars   *document.FieldBuffer
	Doc    document.Document
	Tx     *database.Transaction

	Outer *Environment
}

Environment contains information about the context in which the expression is evaluated.

func NewEnvironment 

func NewEnvironment(d document.Document, params ...Param) *Environment

func (*Environment) Clone 

func (e *Environment) Clone() (*Environment, error)

func (*Environment) Get 

func (e *Environment) Get(path document.Path) (v document.Value, ok bool)

func (*Environment) GetDocument 

func (e *Environment) GetDocument() (document.Document, bool)

func (*Environment) GetParamByIndex 

func (e *Environment) GetParamByIndex(pos int) (document.Value, error)

func (*Environment) GetParamByName 

func (e *Environment) GetParamByName(name string) (v document.Value, err error)

func (*Environment) GetTx 

func (e *Environment) GetTx() *database.Transaction

func (*Environment) Set 

func (e *Environment) Set(name string, v document.Value)

func (*Environment) SetDocument 

func (e *Environment) SetDocument(d document.Document)

type Expr 

type Expr interface {
	Eval(*Environment) (document.Value, error)
	String() string
}

An Expr evaluates to a value.

func Add 

func Add(a, b Expr) Expr

Add creates an expression thats evaluates to the result of a + b.

func And 

func And(a, b Expr) Expr

And creates an expression that evaluates a And b And returns true if both are truthy.

func BitwiseAnd 

func BitwiseAnd(a, b Expr) Expr

BitwiseAnd creates an expression thats evaluates to the result of a & b.

func BitwiseOr 

func BitwiseOr(a, b Expr) Expr

BitwiseOr creates an expression thats evaluates to the result of a | b.

func BitwiseXor 

func BitwiseXor(a, b Expr) Expr

BitwiseXor creates an expression thats evaluates to the result of a ^ b.

func Concat 

func Concat(a, b Expr) Expr

Concat creates an expression that concatenates two text values together. It returns null if one of the values is not a text.

func Div 

func Div(a, b Expr) Expr

Div creates an expression thats evaluates to the result of a / b.

func Eq 

func Eq(a, b Expr) Expr

Eq creates an expression that returns true if a equals b.

func Gt 

func Gt(a, b Expr) Expr

Gt creates an expression that returns true if a is greater than b.

func Gte 

func Gte(a, b Expr) Expr

Gte creates an expression that returns true if a is greater than or equal to b.

func In 

func In(a, b Expr) Expr

In creates an expression that evaluates to the result of a IN b.

func Is 

func Is(a, b Expr) Expr

Is creates an expression that evaluates to the result of a IS b.

func IsNot 

func IsNot(a, b Expr) Expr

IsNot creates an expression that evaluates to the result of a IS NOT b.

func Like 

func Like(a, b Expr) Expr

Like creates an expression that evaluates to the result of a LIKE b.

func Lt 

func Lt(a, b Expr) Expr

Lt creates an expression that returns true if a is lesser than b.

func Lte 

func Lte(a, b Expr) Expr

Lte creates an expression that returns true if a is lesser than or equal to b.

func Mod 

func Mod(a, b Expr) Expr

Mod creates an expression thats evaluates to the result of a % b.

func Mul 

func Mul(a, b Expr) Expr

Mul creates an expression thats evaluates to the result of a * b.

func Neq 

func Neq(a, b Expr) Expr

Neq creates an expression that returns true if a equals b.

func Not 

func Not(e Expr) Expr

Not creates an expression that returns true if e is falsy.

func NotIn 

func NotIn(a, b Expr) Expr

NotIn creates an expression that evaluates to the result of a NOT IN b.

func NotLike 

func NotLike(a, b Expr) Expr

NotLike creates an expression that evaluates to the result of a NOT LIKE b.

func Or 

func Or(a, b Expr) Expr

Or creates an expression that first evaluates a, returns true if truthy, then evaluates b, returns true if truthy Or false if falsy.

func Sub 

func Sub(a, b Expr) Expr

Sub creates an expression thats evaluates to the result of a - b.

type Function 

type Function interface {
	Expr

	// Returns the list of parameters this function has received.
	Params() []Expr
}

A Function is an expression that execute some arbitrary code.

type Functions 

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

Functions represents a map of builtin SQL functions.

func NewFunctions 

func NewFunctions() Functions

func (Functions) AddFunc 

func (f Functions) AddFunc(name string, fn func(args ...Expr) (Expr, error))

AddFunc adds function to the map.

func (Functions) GetFunc 

func (f Functions) GetFunc(name string, args ...Expr) (Expr, error)

GetFunc return a function expression by name.

type InOperator 

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

func (*InOperator) Eval 

func (op *InOperator) Eval(env *Environment) (document.Value, error)

func (InOperator) IsEqual 

func (op InOperator) IsEqual(other Expr) bool

Equal compares this expression with the other expression and returns true if they are equal.

func (InOperator) LeftHand 

func (op InOperator) LeftHand() Expr

func (InOperator) Precedence 

func (op InOperator) Precedence() int

func (InOperator) RightHand 

func (op InOperator) RightHand() Expr

func (InOperator) SetLeftHandExpr 

func (op InOperator) SetLeftHandExpr(a Expr)

func (InOperator) SetRightHandExpr 

func (op InOperator) SetRightHandExpr(b Expr)

func (InOperator) String 

func (op InOperator) String() string

func (InOperator) Token 

func (op InOperator) Token() scanner.Token

type IsNotOperator 

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

func (*IsNotOperator) Eval 

func (op *IsNotOperator) Eval(env *Environment) (document.Value, error)

func (IsNotOperator) IsEqual 

func (op IsNotOperator) IsEqual(other Expr) bool

Equal compares this expression with the other expression and returns true if they are equal.

func (IsNotOperator) LeftHand 

func (op IsNotOperator) LeftHand() Expr

func (IsNotOperator) Precedence 

func (op IsNotOperator) Precedence() int

func (IsNotOperator) RightHand 

func (op IsNotOperator) RightHand() Expr

func (IsNotOperator) SetLeftHandExpr 

func (op IsNotOperator) SetLeftHandExpr(a Expr)

func (IsNotOperator) SetRightHandExpr 

func (op IsNotOperator) SetRightHandExpr(b Expr)

func (*IsNotOperator) String 

func (op *IsNotOperator) String() string

func (IsNotOperator) Token 

func (op IsNotOperator) Token() scanner.Token

type IsOperator 

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

func (*IsOperator) Eval 

func (op *IsOperator) Eval(env *Environment) (document.Value, error)

func (IsOperator) IsEqual 

func (op IsOperator) IsEqual(other Expr) bool

Equal compares this expression with the other expression and returns true if they are equal.

func (IsOperator) LeftHand 

func (op IsOperator) LeftHand() Expr

func (IsOperator) Precedence 

func (op IsOperator) Precedence() int

func (IsOperator) RightHand 

func (op IsOperator) RightHand() Expr

func (IsOperator) SetLeftHandExpr 

func (op IsOperator) SetLeftHandExpr(a Expr)

func (IsOperator) SetRightHandExpr 

func (op IsOperator) SetRightHandExpr(b Expr)

func (IsOperator) String 

func (op IsOperator) String() string

func (IsOperator) Token 

func (op IsOperator) Token() scanner.Token

type KVPair 

type KVPair struct {
	K string
	V Expr
}

KVPair associates an identifier with an expression.

func (KVPair) String 

func (p KVPair) String() string

String implements the stringutil.Stringer interface.

type KVPairs 

type KVPairs struct {
	Pairs          []KVPair
	SelfReferenced bool
}

KVPairs is a list of KVPair.

func (KVPairs) Eval 

func (kvp KVPairs) Eval(env *Environment) (document.Value, error)

Eval turns a list of KVPairs into a document.

func (*KVPairs) IsEqual 

func (kvp *KVPairs) IsEqual(other Expr) bool

IsEqual compares this expression with the other expression and returns true if they are equal.

func (KVPairs) String 

func (kvp KVPairs) String() string

String implements the stringutil.Stringer interface.

type LikeOperator 

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

func (*LikeOperator) Eval 

func (op *LikeOperator) Eval(env *Environment) (document.Value, error)

func (LikeOperator) IsEqual 

func (op LikeOperator) IsEqual(other Expr) bool

Equal compares this expression with the other expression and returns true if they are equal.

func (LikeOperator) LeftHand 

func (op LikeOperator) LeftHand() Expr

func (LikeOperator) Precedence 

func (op LikeOperator) Precedence() int

func (LikeOperator) RightHand 

func (op LikeOperator) RightHand() Expr

func (LikeOperator) SetLeftHandExpr 

func (op LikeOperator) SetLeftHandExpr(a Expr)

func (LikeOperator) SetRightHandExpr 

func (op LikeOperator) SetRightHandExpr(b Expr)

func (LikeOperator) String 

func (op LikeOperator) String() string

func (LikeOperator) Token 

func (op LikeOperator) Token() scanner.Token

type LiteralExprList 

type LiteralExprList []Expr

LiteralExprList is a list of expressions.

func (LiteralExprList) Eval 

func (l LiteralExprList) Eval(env *Environment) (document.Value, error)

Eval evaluates all the expressions and returns a litteralValueList. It implements the Expr interface.

func (LiteralExprList) IsEqual 

func (l LiteralExprList) IsEqual(other Expr) bool

IsEqual compares this expression with the other expression and returns true if they are equal.

func (LiteralExprList) String 

func (l LiteralExprList) String() string

String implements the stringutil.Stringer interface.

type LiteralValue 

type LiteralValue document.Value

A LiteralValue represents a litteral value of any type defined by the value package.

func (LiteralValue) Eval 

func (v LiteralValue) Eval(*Environment) (document.Value, error)

Eval returns l. It implements the Expr interface.

func (LiteralValue) IsEqual 

func (v LiteralValue) IsEqual(other Expr) bool

IsEqual compares this expression with the other expression and returns true if they are equal.

func (LiteralValue) String 

func (v LiteralValue) String() string

String implements the stringutil.Stringer interface.

type MaxAggregator 

type MaxAggregator struct {
	Fn  *MaxFunc
	Max document.Value
}

MaxAggregator is an aggregator that returns the minimum non-null value.

func (*MaxAggregator) Aggregate 

func (m *MaxAggregator) Aggregate(env *Environment) error

Aggregate stores the maximum value. Values are compared based on their types, then if the type is equal their value is compared. Numbers are considered of the same type.

func (*MaxAggregator) Eval 

func (m *MaxAggregator) Eval(env *Environment) (document.Value, error)

Eval return the maximum value.

func (*MaxAggregator) String 

func (m *MaxAggregator) String() string

type MaxFunc 

type MaxFunc struct {
	Expr Expr
}

MaxFunc is the MAX aggregator function.

func (*MaxFunc) Aggregator 

func (m *MaxFunc) Aggregator() Aggregator

Aggregator returns a MaxAggregator. It implements the AggregatorBuilder interface.

func (*MaxFunc) Eval 

func (m *MaxFunc) Eval(env *Environment) (document.Value, error)

Eval extracts the max value from the given document and returns it.

func (*MaxFunc) IsEqual 

func (m *MaxFunc) IsEqual(other Expr) bool

IsEqual compares this expression with the other expression and returns true if they are equal.

func (*MaxFunc) Params 

func (m *MaxFunc) Params() []Expr

func (*MaxFunc) String 

func (m *MaxFunc) String() string

String returns the alias if non-zero, otherwise it returns a string representation of the count expression.

type MinAggregator 

type MinAggregator struct {
	Fn  *MinFunc
	Min document.Value
}

MinAggregator is an aggregator that returns the minimum non-null value.

func (*MinAggregator) Aggregate 

func (m *MinAggregator) Aggregate(env *Environment) error

Aggregate stores the minimum value. Values are compared based on their types, then if the type is equal their value is compared. Numbers are considered of the same type.

func (*MinAggregator) Eval 

func (m *MinAggregator) Eval(env *Environment) (document.Value, error)

Eval return the minimum value.

func (*MinAggregator) String 

func (m *MinAggregator) String() string

type MinFunc 

type MinFunc struct {
	Expr Expr
}

MinFunc is the MIN aggregator function.

func (*MinFunc) Aggregator 

func (m *MinFunc) Aggregator() Aggregator

Aggregator returns a MinAggregator. It implements the AggregatorBuilder interface.

func (*MinFunc) Eval 

func (m *MinFunc) Eval(env *Environment) (document.Value, error)

Eval extracts the min value from the given document and returns it.

func (*MinFunc) IsEqual 

func (m *MinFunc) IsEqual(other Expr) bool

IsEqual compares this expression with the other expression and returns true if they are equal.

func (*MinFunc) Params 

func (m *MinFunc) Params() []Expr

func (*MinFunc) String 

func (m *MinFunc) String() string

String returns the alias if non-zero, otherwise it returns a string representation of the count expression.

type NamedExpr 

type NamedExpr struct {
	Expr

	ExprName string
}

NamedExpr is an expression with a name.

func (NamedExpr) Name 

func (e NamedExpr) Name() string

Name returns ExprName.

func (NamedExpr) String 

func (e NamedExpr) String() string

type NamedParam 

type NamedParam string

NamedParam is an expression which represents the name of a parameter.

func (NamedParam) Eval 

func (p NamedParam) Eval(env *Environment) (document.Value, error)

Eval looks up for the parameters in the env for the one that has the same name as p and returns the value.

func (NamedParam) IsEqual 

func (p NamedParam) IsEqual(other Expr) bool

IsEqual compares this expression with the other expression and returns true if they are equal.

func (NamedParam) String 

func (p NamedParam) String() string

String implements the stringutil.Stringer interface.

type NotInOperator 

type NotInOperator struct {
	InOperator
}

func (*NotInOperator) Eval 

func (op *NotInOperator) Eval(env *Environment) (document.Value, error)

func (NotInOperator) IsEqual 

func (op NotInOperator) IsEqual(other Expr) bool

Equal compares this expression with the other expression and returns true if they are equal.

func (NotInOperator) LeftHand 

func (op NotInOperator) LeftHand() Expr

func (NotInOperator) Precedence 

func (op NotInOperator) Precedence() int

func (NotInOperator) RightHand 

func (op NotInOperator) RightHand() Expr

func (NotInOperator) SetLeftHandExpr 

func (op NotInOperator) SetLeftHandExpr(a Expr)

func (NotInOperator) SetRightHandExpr 

func (op NotInOperator) SetRightHandExpr(b Expr)

func (*NotInOperator) String 

func (op *NotInOperator) String() string

func (NotInOperator) Token 

func (op NotInOperator) Token() scanner.Token

type NotLikeOperator 

type NotLikeOperator struct {
	LikeOperator
}

func (*NotLikeOperator) Eval 

func (op *NotLikeOperator) Eval(env *Environment) (document.Value, error)

func (NotLikeOperator) IsEqual 

func (op NotLikeOperator) IsEqual(other Expr) bool

Equal compares this expression with the other expression and returns true if they are equal.

func (NotLikeOperator) LeftHand 

func (op NotLikeOperator) LeftHand() Expr

func (NotLikeOperator) Precedence 

func (op NotLikeOperator) Precedence() int

func (NotLikeOperator) RightHand 

func (op NotLikeOperator) RightHand() Expr

func (NotLikeOperator) SetLeftHandExpr 

func (op NotLikeOperator) SetLeftHandExpr(a Expr)

func (NotLikeOperator) SetRightHandExpr 

func (op NotLikeOperator) SetRightHandExpr(b Expr)

func (*NotLikeOperator) String 

func (op *NotLikeOperator) String() string

func (NotLikeOperator) Token 

func (op NotLikeOperator) Token() scanner.Token

type NotOp 

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

NotOp is the NOT unary operator.

func (*NotOp) Eval 

func (op *NotOp) Eval(env *Environment) (document.Value, error)

Eval implements the Expr interface. It evaluates e and returns true if b is falsy

func (NotOp) IsEqual 

func (op NotOp) IsEqual(other Expr) bool

Equal compares this expression with the other expression and returns true if they are equal.

func (NotOp) LeftHand 

func (op NotOp) LeftHand() Expr

func (NotOp) Precedence 

func (op NotOp) Precedence() int

func (NotOp) RightHand 

func (op NotOp) RightHand() Expr

func (NotOp) SetLeftHandExpr 

func (op NotOp) SetLeftHandExpr(a Expr)

func (NotOp) SetRightHandExpr 

func (op NotOp) SetRightHandExpr(b Expr)

func (*NotOp) String 

func (op *NotOp) String() string

String implements the stringutil.Stringer interface.

func (NotOp) Token 

func (op NotOp) Token() scanner.Token

type Operator 

type Operator interface {
	Expr

	Precedence() int
	LeftHand() Expr
	RightHand() Expr
	SetLeftHandExpr(Expr)
	SetRightHandExpr(Expr)
	Token() scanner.Token
}

An Operator is a binary expression that takes two operands and executes an operation on them.

type OrOp 

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

OrOp is the Or operator.

func (*OrOp) Eval 

func (op *OrOp) Eval(env *Environment) (document.Value, error)

Eval implements the Expr interface. It evaluates a and b and returns true if a or b evalutate to true.

func (OrOp) IsEqual 

func (op OrOp) IsEqual(other Expr) bool

Equal compares this expression with the other expression and returns true if they are equal.

func (OrOp) LeftHand 

func (op OrOp) LeftHand() Expr

func (OrOp) Precedence 

func (op OrOp) Precedence() int

func (OrOp) RightHand 

func (op OrOp) RightHand() Expr

func (OrOp) SetLeftHandExpr 

func (op OrOp) SetLeftHandExpr(a Expr)

func (OrOp) SetRightHandExpr 

func (op OrOp) SetRightHandExpr(b Expr)

func (OrOp) String 

func (op OrOp) String() string

func (OrOp) Token 

func (op OrOp) Token() scanner.Token

type PKFunc 

type PKFunc struct{}

PKFunc represents the pk() function. It returns the primary key of the current document.

func (*PKFunc) Eval 

func (k *PKFunc) Eval(env *Environment) (document.Value, error)

Eval returns the primary key of the current document.

func (*PKFunc) IsEqual 

func (k *PKFunc) IsEqual(other Expr) bool

IsEqual compares this expression with the other expression and returns true if they are equal.

func (*PKFunc) Params 

func (*PKFunc) Params() []Expr

func (*PKFunc) String 

func (k *PKFunc) String() string

type Param 

type Param struct {
	// Name of the param
	Name string

	// Value is the parameter value.
	Value interface{}
}

A Param represents a parameter passed by the user to the statement.

type Parentheses 

type Parentheses struct {
	E Expr
}

Parentheses is a special expression which turns any sub-expression as unary. It hides the underlying operator, if any, from the parser so that it doesn't get reordered by precedence.

func (Parentheses) Eval 

func (p Parentheses) Eval(env *Environment) (document.Value, error)

Eval calls the underlying expression Eval method.

func (Parentheses) IsEqual 

func (p Parentheses) IsEqual(other Expr) bool

IsEqual compares this expression with the other expression and returns true if they are equal.

func (Parentheses) String 

func (p Parentheses) String() string

type Path 

type Path document.Path

A Path is an expression that extracts a value from a document at a given path.

func (Path) Eval 

func (p Path) Eval(env *Environment) (document.Value, error)

Eval extracts the current value from the environment and returns the value stored at p. It implements the Expr interface.

func (Path) IsEqual 

func (p Path) IsEqual(other Expr) bool

IsEqual compares this expression with the other expression and returns true if they are equal.

func (Path) String 

func (p Path) String() string

type PositionalParam 

type PositionalParam int

PositionalParam is an expression which represents the position of a parameter.

func (PositionalParam) Eval 

func (p PositionalParam) Eval(env *Environment) (document.Value, error)

Eval looks up for the parameters in the env for the one that is has the same position as p and returns the value.

func (PositionalParam) IsEqual 

func (p PositionalParam) IsEqual(other Expr) bool

IsEqual compares this expression with the other expression and returns true if they are equal.

func (PositionalParam) String 

func (p PositionalParam) String() string

String implements the stringutil.Stringer interface.

type SumAggregator 

type SumAggregator struct {
	Fn   *SumFunc
	SumI *int64
	SumF *float64
}

SumAggregator is an aggregator that returns the minimum non-null value.

func (*SumAggregator) Aggregate 

func (s *SumAggregator) Aggregate(env *Environment) error

Aggregate stores the sum of all non-NULL numeric values in the group. The result is an integer value if all summed values are integers. If any of the value is a double, the returned result will be a double.

func (*SumAggregator) Eval 

func (s *SumAggregator) Eval(env *Environment) (document.Value, error)

Eval return the aggregated sum.

func (*SumAggregator) String 

func (s *SumAggregator) String() string

type SumFunc 

type SumFunc struct {
	Expr Expr
}

SumFunc is the SUM aggregator function.

func (*SumFunc) Aggregator 

func (s *SumFunc) Aggregator() Aggregator

Aggregator returns a SumFunc. It implements the AggregatorBuilder interface.

func (*SumFunc) Eval 

func (s *SumFunc) Eval(env *Environment) (document.Value, error)

Eval extracts the sum value from the given document and returns it.

func (*SumFunc) IsEqual 

func (s *SumFunc) IsEqual(other Expr) bool

IsEqual compares this expression with the other expression and returns true if they are equal.

func (*SumFunc) Params 

func (s *SumFunc) Params() []Expr

func (*SumFunc) String 

func (s *SumFunc) String() string

String returns the alias if non-zero, otherwise it returns a string representation of the count expression.

type Wildcard 

type Wildcard struct{}

A Wildcard is an expression that iterates over all the fields of a document.

func (Wildcard) Eval 

func (w Wildcard) Eval(env *Environment) (document.Value, error)

func (Wildcard) Iterate 

func (w Wildcard) Iterate(env *Environment, fn func(field string, value document.Value) error) error

Iterate call the document iterate method.

func (Wildcard) String 

func (w Wildcard) 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.