evaluator

type ArrayOps interface {
	// Graph returns the graph to which new nodes are being added.
	Graph() ops.Graph

	// SubGraph returns a new graph builder.
	SubGraph(name string, args []*shape.Shape) (ArrayOps, error)

	// Einsum calls an einstein sum on x and y given the expression in ref.
	Einsum(ctx ir.Evaluator, expr *ir.EinsumExpr, x, y NumericalElement) (NumericalElement, error)

	// BroadcastInDim the data of an array across dimensions.
	BroadcastInDim(ctx ir.Evaluator, expr ir.AssignableExpr, x NumericalElement, axisLengths []NumericalElement) (NumericalElement, error)

	// Concat concatenates scalars elements into an array with one axis.
	Concat(ctx ir.Evaluator, expr ir.AssignableExpr, xs []NumericalElement) (NumericalElement, error)

	// Set a slice in an array.
	Set(ctx ir.Evaluator, expr *ir.CallExpr, x, updates, index ir.Element) (ir.Element, error)

	// ElementFromArray returns an element from an array GX value.
	ElementFromArray(ctx ir.Evaluator, expr ir.AssignableExpr, val values.Array) (NumericalElement, error)
}

type Context interface {
	ir.Evaluator

	// Evaluator returns the evaluator used by the interpreter.
	Evaluator() Evaluator

	// Materialiser returns the materialiser to convert elements into graph nodes.
	Materialiser() materialise.Materialiser
}

type Evaluator interface {
	// Importer returns an importer to import package.
	Importer() ir.Importer

	// ArrayOps returns the operator implementations for arrays.
	ArrayOps() ArrayOps

	// Processor returns the used by the array evaluator.
	Processor() *processor.Processor

	// ElementFromAtom returns an element from an atomic GX value.
	ElementFromAtom(ctx ir.Evaluator, expr ir.AssignableExpr, val values.Array) (NumericalElement, error)

	// Trace register a call to the trace builtin function.
	Trace(ctx ir.Evaluator, call *ir.CallExpr, args []ir.Element) error
}

type NumericalElement interface {
	ir.Element

	// UnaryOp applies a unary operator on x.
	UnaryOp(ctx ir.Evaluator, expr *ir.UnaryExpr) (NumericalElement, error)

	// BinaryOp applies a binary operator to x and y.
	// Note that the receiver can be either the left or right argument.
	BinaryOp(ctx ir.Evaluator, expr *ir.BinaryExpr, x, y NumericalElement) (NumericalElement, error)

	// Cast an element into a given data type.
	Cast(ctx ir.Evaluator, expr ir.AssignableExpr, target ir.Type) (NumericalElement, error)

	// Reshape an element.
	Reshape(ctx ir.Evaluator, expr ir.AssignableExpr, axisLengths []NumericalElement) (NumericalElement, error)
}