ast/ast.go

package ast

import "matheval/token"

// Node is the interface all AST nodes implement.
// The unexported marker method seals the interface — only types
// in this package can implement it.
type Node interface {
	node() // sealed marker
}

// NumberLit represents a numeric literal (e.g. 3.14).
type NumberLit struct {
	Value float64
}

func (*NumberLit) node() {}

// BinaryExpr represents a binary operation (e.g. 1 + 2).
type BinaryExpr struct {
	Op    token.Type // Plus, Minus, Star, Slash
	Left  Node
	Right Node
}

func (*BinaryExpr) node() {}