package scanner

import "math"

type TokenType int

const (
	// reserved word
	ORIGIN TokenType = iota
	ROT
	SCALE
	IS
	FOR
	FROM
	TO
	STEP
	DRAW
	COLOR
	// parameter
	T
	// sparator
	SEMICO
	L_BRACKET
	R_BRACKET
	COMMA
	// operator
	PLUS
	MINUS
	MUL
	DIV
	POWER
	// other
	FUNC
	CONST_ID
	NONTOKEN
	ERRTOKEN
)

type Token struct {
	Type   TokenType
	Lexeme string
	Value  float64
	Func   func(float64) float64
}

var keywords = map[string]Token{
	"ORIGIN": {Type: ORIGIN, Lexeme: "ORIGIN"},
	"ROT":    {Type: ROT, Lexeme: "ROT"},
	"SCALE":  {Type: SCALE, Lexeme: "SCALE"},
	"IS":     {Type: IS, Lexeme: "IS"},
	"FOR":    {Type: FOR, Lexeme: "FOR"},
	"FROM":   {Type: FROM, Lexeme: "FROM"},
	"TO":     {Type: TO, Lexeme: "TO"},
	"STEP":   {Type: STEP, Lexeme: "STEP"},
	"DRAW":   {Type: DRAW, Lexeme: "DRAW"},
	"COLOR":  {Type: COLOR, Lexeme: "COLOR"},
	"T":      {Type: T, Lexeme: "T"},
	"PI":     {Type: CONST_ID, Lexeme: "PI", Value: math.Pi},
	"E":      {Type: CONST_ID, Lexeme: "E", Value: math.E},
	"SIN":    {Type: FUNC, Lexeme: "SIN", Func: math.Sin},
	"COS":    {Type: FUNC, Lexeme: "COS", Func: math.Cos},
	"TAN":    {Type: FUNC, Lexeme: "TAN", Func: math.Tan},
	"LN":     {Type: FUNC, Lexeme: "LN", Func: math.Log},
	"EXP":    {Type: FUNC, Lexeme: "EXP", Func: math.Exp},
	"SQRT":   {Type: FUNC, Lexeme: "SQRT", Func: math.Sqrt},
}