// Copyright 2015 The Go Authors. All rights reserved.

// Use of this source code is governed by a BSD-style

// license that can be found in the LICENSE file.

// +build ignore

package main

// Class is the Unicode BiDi class. Each rune has a single class.

type Class uint

const (

	L       Class = iota // LeftToRight

	R                    // RightToLeft

	EN                   // EuropeanNumber

	ES                   // EuropeanSeparator

	ET                   // EuropeanTerminator

	AN                   // ArabicNumber

	CS                   // CommonSeparator

	B                    // ParagraphSeparator

	S                    // SegmentSeparator

	WS                   // WhiteSpace

	ON                   // OtherNeutral

	BN                   // BoundaryNeutral

	NSM                  // NonspacingMark

	AL                   // ArabicLetter

	Control              // Control LRO - PDI

	numClass

	LRO // LeftToRightOverride

	RLO // RightToLeftOverride

	LRE // LeftToRightEmbedding

	RLE // RightToLeftEmbedding

	PDF // PopDirectionalFormat

	LRI // LeftToRightIsolate

	RLI // RightToLeftIsolate

	FSI // FirstStrongIsolate

	PDI // PopDirectionalIsolate

	unknownClass = ^Class(0)

)

var controlToClass = map[rune]Class{

	0x202D: LRO, // LeftToRightOverride,

	0x202E: RLO, // RightToLeftOverride,

	0x202A: LRE, // LeftToRightEmbedding,

	0x202B: RLE, // RightToLeftEmbedding,

	0x202C: PDF, // PopDirectionalFormat,

	0x2066: LRI, // LeftToRightIsolate,

	0x2067: RLI, // RightToLeftIsolate,

	0x2068: FSI, // FirstStrongIsolate,

	0x2069: PDI, // PopDirectionalIsolate,

}

// A trie entry has the following bits:

// 7..5  XOR mask for brackets

// 4     1: Bracket open, 0: Bracket close

// 3..0  Class type

const (

	openMask     = 0x10

	xorMaskShift = 5

)