expression

Documentation

Index

• type AbstractExpression
• type AggregateValueExpression
  • func (a *AggregateValueExpression) Evaluate(tuple *tuple.Tuple, schema *schema.Schema) types.Value
  • func (a *AggregateValueExpression) EvaluateAggregate(group_bys []*types.Value, aggregates []*types.Value) types.Value
  • func (a *AggregateValueExpression) EvaluateJoin(left_tuple *tuple.Tuple, left_schema *schema.Schema, right_tuple *tuple.Tuple, ...) types.Value
  • func (a *AggregateValueExpression) GetChildAt(child_idx uint32) Expression
  • func (a *AggregateValueExpression) GetReturnType() types.TypeID
• type ColumnValue
  • func (c *ColumnValue) Evaluate(tuple *tuple.Tuple, schema *schema.Schema) types.Value
  • func (c *ColumnValue) EvaluateAggregate(group_bys []*types.Value, aggregates []*types.Value) types.Value
  • func (c *ColumnValue) EvaluateJoin(left_tuple *tuple.Tuple, left_schema *schema.Schema, right_tuple *tuple.Tuple, ...) types.Value
  • func (c *ColumnValue) GetChildAt(child_idx uint32) Expression
  • func (c *ColumnValue) GetReturnType() types.TypeID
  • func (c *ColumnValue) SetColIndex(colIndex uint32)
  • func (c *ColumnValue) SetReturnType(valueType types.TypeID)
  • func (c *ColumnValue) SetTupleIndex(tupleIndex uint32)
• type Comparison
  • func (c *Comparison) Evaluate(tuple_ *tuple.Tuple, schema_ *schema.Schema) types.Value
  • func (c *Comparison) EvaluateAggregate(group_bys []*types.Value, aggregates []*types.Value) types.Value
  • func (c *Comparison) EvaluateJoin(left_tuple *tuple.Tuple, left_schema *schema.Schema, right_tuple *tuple.Tuple, ...) types.Value
  • func (c *Comparison) GetChildAt(child_idx uint32) Expression
  • func (c *Comparison) GetComparisonType() ComparisonType
  • func (c *Comparison) GetLeftSideColIdx() uint32
  • func (c *Comparison) GetRightSideValue(tuple_ *tuple.Tuple, schema_ *schema.Schema) types.Value
  • func (c *Comparison) SetChildAt(child_idx uint32, child Expression)
• type ComparisonType
• type ConstantValue
  • func (c *ConstantValue) Evaluate(tuple *tuple.Tuple, schema *schema.Schema) types.Value
  • func (c *ConstantValue) EvaluateAggregate(group_bys []*types.Value, aggregates []*types.Value) types.Value
  • func (c *ConstantValue) EvaluateJoin(left_tuple *tuple.Tuple, left_schema *schema.Schema, right_tuple *tuple.Tuple, ...) types.Value
  • func (c *ConstantValue) GetChildAt(child_idx uint32) Expression
• type Expression
  • func NewAggregateValueExpression(is_group_by_term bool, term_idx uint32, ret_type types.TypeID) Expression
  • func NewColumnValue(tupleIndex uint32, colIndex uint32, colType types.TypeID) Expression
  • func NewComparison(left Expression, right Expression, comparisonType ComparisonType, ...) Expression
  • func NewConstantValue(value types.Value, colType types.TypeID) Expression
  • func NewLogicalOp(left Expression, right Expression, logicalOpType LogicalOpType, ...) Expression
• type LogicalOp
  • func (c *LogicalOp) Evaluate(tuple *tuple.Tuple, schema *schema.Schema) types.Value
  • func (c *LogicalOp) EvaluateAggregate(group_bys []*types.Value, aggregates []*types.Value) types.Value
  • func (c *LogicalOp) EvaluateJoin(left_tuple *tuple.Tuple, left_schema *schema.Schema, right_tuple *tuple.Tuple, ...) types.Value
  • func (c *LogicalOp) GetChildAt(child_idx uint32) Expression
  • func (c *LogicalOp) GetLogicalOpType() LogicalOpType
  • func (c *LogicalOp) SetChildAt(child_idx uint32, child Expression)
• type LogicalOpType

Types

type AbstractExpression

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

type AggregateValueExpression

type AggregateValueExpression struct {
	*AbstractExpression
	// contains filtered or unexported fields
}

*

• AggregateValueExpression represents aggregations such as MAX(a), MIN(b), COUNT(c)

func (*AggregateValueExpression) Evaluate

func (a *AggregateValueExpression) Evaluate(tuple *tuple.Tuple, schema *schema.Schema) types.Value

func (*AggregateValueExpression) EvaluateAggregate

func (a *AggregateValueExpression) EvaluateAggregate(group_bys []*types.Value, aggregates []*types.Value) types.Value

func (*AggregateValueExpression) EvaluateJoin

func (a *AggregateValueExpression) EvaluateJoin(left_tuple *tuple.Tuple, left_schema *schema.Schema, right_tuple *tuple.Tuple, right_schema *schema.Schema) types.Value

func (*AggregateValueExpression) GetChildAt

func (a *AggregateValueExpression) GetChildAt(child_idx uint32) Expression

func (*AggregateValueExpression) GetReturnType

func (a *AggregateValueExpression) GetReturnType() types.TypeID

type ColumnValue

type ColumnValue struct {
	*AbstractExpression
	// contains filtered or unexported fields
}

*

• ColumnValue maintains the tuple index and column index relative to a particular schema or join.

func (*ColumnValue) Evaluate

func (c *ColumnValue) Evaluate(tuple *tuple.Tuple, schema *schema.Schema) types.Value

func (*ColumnValue) EvaluateAggregate

func (c *ColumnValue) EvaluateAggregate(group_bys []*types.Value, aggregates []*types.Value) types.Value

func (*ColumnValue) EvaluateJoin

func (c *ColumnValue) EvaluateJoin(left_tuple *tuple.Tuple, left_schema *schema.Schema, right_tuple *tuple.Tuple, right_schema *schema.Schema) types.Value

func (*ColumnValue) GetChildAt

func (c *ColumnValue) GetChildAt(child_idx uint32) Expression

func (*ColumnValue) GetReturnType

func (c *ColumnValue) GetReturnType() types.TypeID

func (*ColumnValue) SetColIndex

func (c *ColumnValue) SetColIndex(colIndex uint32)

func (*ColumnValue) SetReturnType

func (c *ColumnValue) SetReturnType(valueType types.TypeID)

func (*ColumnValue) SetTupleIndex

func (c *ColumnValue) SetTupleIndex(tupleIndex uint32)

type Comparison

type Comparison struct {
	*AbstractExpression
	// contains filtered or unexported fields
}

*

• ComparisonExpression represents two expressions being compared.

func (*Comparison) Evaluate

func (c *Comparison) Evaluate(tuple_ *tuple.Tuple, schema_ *schema.Schema) types.Value

func (*Comparison) EvaluateAggregate

func (c *Comparison) EvaluateAggregate(group_bys []*types.Value, aggregates []*types.Value) types.Value

func (*Comparison) EvaluateJoin

func (c *Comparison) EvaluateJoin(left_tuple *tuple.Tuple, left_schema *schema.Schema, right_tuple *tuple.Tuple, right_schema *schema.Schema) types.Value

func (*Comparison) GetChildAt

func (c *Comparison) GetChildAt(child_idx uint32) Expression

func (*Comparison) GetComparisonType

func (c *Comparison) GetComparisonType() ComparisonType

func (*Comparison) GetLeftSideColIdx

func (c *Comparison) GetLeftSideColIdx() uint32

func (*Comparison) GetRightSideValue

func (c *Comparison) GetRightSideValue(tuple_ *tuple.Tuple, schema_ *schema.Schema) types.Value

func (*Comparison) SetChildAt

func (c *Comparison) SetChildAt(child_idx uint32, child Expression)

type ComparisonType

type ComparisonType int

const (
	Equal ComparisonType = iota
	NotEqual
	GreaterThan        // A > B
	GreaterThanOrEqual // A >= B
	LessThan           // A < B
	LessThanOrEqual    // A <= B
)

* ComparisonType represents the type of comparison that we want to perform.

type ConstantValue

type ConstantValue struct {
	*AbstractExpression
	// contains filtered or unexported fields
}

*

• ConstantValue represents constants.

func (*ConstantValue) Evaluate

func (c *ConstantValue) Evaluate(tuple *tuple.Tuple, schema *schema.Schema) types.Value

func (*ConstantValue) EvaluateAggregate

func (c *ConstantValue) EvaluateAggregate(group_bys []*types.Value, aggregates []*types.Value) types.Value

func (*ConstantValue) EvaluateJoin

func (c *ConstantValue) EvaluateJoin(left_tuple *tuple.Tuple, left_schema *schema.Schema, right_tuple *tuple.Tuple, right_schema *schema.Schema) types.Value

func (*ConstantValue) GetChildAt

func (c *ConstantValue) GetChildAt(child_idx uint32) Expression

type Expression

type Expression interface {
	Evaluate(*tuple.Tuple, *schema.Schema) types.Value
	GetChildAt(uint32) Expression
	EvaluateJoin(*tuple.Tuple, *schema.Schema, *tuple.Tuple, *schema.Schema) types.Value
	EvaluateAggregate([]*types.Value, []*types.Value) types.Value
}

*

• Expression interface is the base of all the expressions in the system.
• Expressions are modeled as trees, i.e. every expression may have a variable number of children.

func NewAggregateValueExpression

func NewAggregateValueExpression(is_group_by_term bool, term_idx uint32, ret_type types.TypeID) Expression

func NewColumnValue

func NewColumnValue(tupleIndex uint32, colIndex uint32, colType types.TypeID) Expression

func NewComparison

func NewComparison(left Expression, right Expression, comparisonType ComparisonType, colType types.TypeID) Expression

func NewConstantValue

func NewConstantValue(value types.Value, colType types.TypeID) Expression

func NewLogicalOp

func NewLogicalOp(left Expression, right Expression, logicalOpType LogicalOpType, colType types.TypeID) Expression

if logicalOpType is "NOT", right value must be nil

type LogicalOp

type LogicalOp struct {
	*AbstractExpression
	// contains filtered or unexported fields
}

*

• LogicalOp represents two expressions or one expression being evaluated with logical operator.

func (*LogicalOp) Evaluate

func (c *LogicalOp) Evaluate(tuple *tuple.Tuple, schema *schema.Schema) types.Value

func (*LogicalOp) EvaluateAggregate

func (c *LogicalOp) EvaluateAggregate(group_bys []*types.Value, aggregates []*types.Value) types.Value

func (*LogicalOp) EvaluateJoin

func (c *LogicalOp) EvaluateJoin(left_tuple *tuple.Tuple, left_schema *schema.Schema, right_tuple *tuple.Tuple, right_schema *schema.Schema) types.Value

func (*LogicalOp) GetChildAt

func (c *LogicalOp) GetChildAt(child_idx uint32) Expression

func (*LogicalOp) GetLogicalOpType

func (c *LogicalOp) GetLogicalOpType() LogicalOpType

func (*LogicalOp) SetChildAt

func (c *LogicalOp) SetChildAt(child_idx uint32, child Expression)

type LogicalOpType

type LogicalOpType int

const (
	AND LogicalOpType = iota
	OR
	NOT
)

* LogicalOpType represents the type of comparison that we want to perform.