transform

Documentation

Index

• type ExprTransformContext
  • func (t *ExprTransformContext) AggregateInExpr(expr tree.Expr, searchPath sessiondata.SearchPath) bool
  • func (t *ExprTransformContext) NormalizeExpr(ctx *tree.EvalContext, typedExpr tree.TypedExpr) (tree.TypedExpr, error)
• type IsAggregateVisitor
  • func (*IsAggregateVisitor) VisitPost(expr tree.Expr) tree.Expr
  • func (v *IsAggregateVisitor) VisitPre(expr tree.Expr) (recurse bool, newExpr tree.Expr)

Types

type ExprTransformContext

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

ExprTransformContext supports the methods that test expression properties and can normalize expressions, defined below. This should be used in planner instance to avoid re-allocation of these visitors between uses.

func (*ExprTransformContext) AggregateInExpr

func (t *ExprTransformContext) AggregateInExpr(
	expr tree.Expr, searchPath sessiondata.SearchPath,
) bool

AggregateInExpr determines if an Expr contains an aggregate function. TODO(knz/radu): this is not the right way to go about checking these things. Instead whatever analysis occurs prior on the expression should collect scalar properties (see tree.ScalarProperties) and then the collected properties should be tested directly.

func (*ExprTransformContext) NormalizeExpr

func (t *ExprTransformContext) NormalizeExpr(
	ctx *tree.EvalContext, typedExpr tree.TypedExpr,
) (tree.TypedExpr, error)

NormalizeExpr is a wrapper around EvalContex.NormalizeExpr which avoids allocation of a normalizeVisitor. See normalize.go for details.

type IsAggregateVisitor

type IsAggregateVisitor struct {
	Aggregated bool
	// contains filtered or unexported fields
}

IsAggregateVisitor checks if walked expressions contain aggregate functions.

func (*IsAggregateVisitor) VisitPost

func (*IsAggregateVisitor) VisitPost(expr tree.Expr) tree.Expr

VisitPost satisfies the Visitor interface.

func (*IsAggregateVisitor) VisitPre

func (v *IsAggregateVisitor) VisitPre(expr tree.Expr) (recurse bool, newExpr tree.Expr)

VisitPre satisfies the Visitor interface.