binding_power.go

package parser

import (
	"github.com/ProCode-Software/klar/internal/lexer"
)

// BindingPower represents the operator precedence for a type of operator.
type BindingPower int

// TypeScript Reference:
// 	https://github.com/microsoft/typescript-go/blob/main/internal/ast/precedence.go

const (
	DefaultBindingPower BindingPower = iota // Zero

	ExpressionBindingPower     // Minimum
	WhenAsBindingPower         // as
	ObjectPipelineBindingPower // |.
	LogicalBindingPower        // ||, &&
	WhenOptionBindingPower     // |
	PipelineBindingPower       // |>
	RelationalBindingPower     // ==, !=, >, <, <=, >=, in, !in
	DistributiveBindingPower   // and, or
	RangeBindingPower          // ..., ..<
	AdditiveBindingPower       // +, -
	MultiplicativeBindingPower // *, /, %
	UnaryBindingPower          // await, go, !
	ExponentiationBindingPower // ^ (higher than unary: -2 ^ 3 = -(2 ^ 3))
	CallBindingPower           // Call: (
	MemberBindingPower         // Index/Slice: . [
	PrimaryBindingPower        // Primary expressions (literals)
)

var BindingPowerMap = map[lexer.TokenType]BindingPower{
	lexer.As: WhenAsBindingPower,

	lexer.StrokeDot: ObjectPipelineBindingPower,

	lexer.AndAnd: LogicalBindingPower,
	lexer.OrOr:   LogicalBindingPower,

	lexer.Stroke: WhenOptionBindingPower,

	lexer.Pipeline: PipelineBindingPower,

	lexer.LessThan:       RelationalBindingPower,
	lexer.GreaterThan:    RelationalBindingPower,
	lexer.LessEqualTo:    RelationalBindingPower,
	lexer.GreaterEqualTo: RelationalBindingPower,
	lexer.EqualEqual:     RelationalBindingPower,
	lexer.NotEqual:       RelationalBindingPower,
	lexer.In:             RelationalBindingPower,
	lexer.NotIn:          RelationalBindingPower,

	lexer.Ellipsis:       RangeBindingPower,
	lexer.DotDotLessThan: RangeBindingPower,

	lexer.And: DistributiveBindingPower,
	lexer.Or:  DistributiveBindingPower,

	lexer.Plus:  AdditiveBindingPower,
	lexer.Minus: AdditiveBindingPower,

	lexer.Asterisk: MultiplicativeBindingPower,
	lexer.Slash:    MultiplicativeBindingPower,
	lexer.Percent:  MultiplicativeBindingPower,

	lexer.NotNot: UnaryBindingPower,
	lexer.Not:    UnaryBindingPower, // For error handling

	lexer.Caret: ExponentiationBindingPower,

	lexer.LeftParenthesis: CallBindingPower,

	lexer.Dot:         MemberBindingPower,
	lexer.LeftBracket: MemberBindingPower,

	lexer.String:     PrimaryBindingPower,
	lexer.Numeric:    PrimaryBindingPower,
	lexer.Boolean:    PrimaryBindingPower,
	lexer.Identifier: PrimaryBindingPower,
	lexer.Nil:        PrimaryBindingPower,
	lexer.Underscore: PrimaryBindingPower,
	lexer.Regex:      PrimaryBindingPower,
}

const (
	_ BindingPower = ExpressionBindingPower + iota
	DefaultTypeBindingPower
	VariadicTypeBindingPower  // ...
	OptionalTypeBindingPower  // ?
	UnionTypeBindingPower     // |
	GenericTypeBindingPower   // <
	NamespaceTypeBindingPower // .
	PrimaryTypeBindingPower   // Names
)

var TypeBindingPowerMap = map[lexer.TokenType]BindingPower{
	lexer.Question: OptionalTypeBindingPower,
	lexer.Stroke:   UnionTypeBindingPower,
	lexer.LessThan: GenericTypeBindingPower,
	lexer.Dot:      NamespaceTypeBindingPower,

	lexer.Identifier: PrimaryTypeBindingPower,
	lexer.Underscore: PrimaryTypeBindingPower,
}

func bpOf(kind lexer.TokenType) BindingPower {
	return BindingPowerMap[kind]
}