cubefs

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// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
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package idna
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// This file contains definitions for interpreting the trie value of the idna
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// trie generated by "go run gen*.go". It is shared by both the generator
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// program and the resultant package. Sharing is achieved by the generator
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// copying gen_trieval.go to trieval.go and changing what's above this comment.
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// info holds information from the IDNA mapping table for a single rune. It is
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// the value returned by a trie lookup. In most cases, all information fits in
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// a 16-bit value. For mappings, this value may contain an index into a slice
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// with the mapped string. Such mappings can consist of the actual mapped value
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// or an XOR pattern to be applied to the bytes of the UTF8 encoding of the
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// input rune. This technique is used by the cases packages and reduces the
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// table size significantly.
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//
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// The per-rune values have the following format:
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//
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//	if mapped {
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//	  if inlinedXOR {
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//	    15..13 inline XOR marker
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//	    12..11 unused
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//	    10..3  inline XOR mask
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//	  } else {
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//	    15..3  index into xor or mapping table
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//	  }
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//	} else {
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//	    15..14 unused
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//	    13     mayNeedNorm
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//	    12..11 attributes
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//	    10..8  joining type
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//	     7..3  category type
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//	}
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//	   2  use xor pattern
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//	1..0  mapped category
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//
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// See the definitions below for a more detailed description of the various
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// bits.
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type info uint16
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const (
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	catSmallMask = 0x3
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	catBigMask   = 0xF8
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	indexShift   = 3
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	xorBit       = 0x4    // interpret the index as an xor pattern
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	inlineXOR    = 0xE000 // These bits are set if the XOR pattern is inlined.
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	joinShift = 8
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	joinMask  = 0x07
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	// Attributes
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	attributesMask = 0x1800
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	viramaModifier = 0x1800
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	modifier       = 0x1000
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	rtl            = 0x0800
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	mayNeedNorm = 0x2000
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)
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// A category corresponds to a category defined in the IDNA mapping table.
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type category uint16
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const (
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	unknown              category = 0 // not currently defined in unicode.
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	mapped               category = 1
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	disallowedSTD3Mapped category = 2
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	deviation            category = 3
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)
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const (
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	valid               category = 0x08
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	validNV8            category = 0x18
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	validXV8            category = 0x28
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	disallowed          category = 0x40
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	disallowedSTD3Valid category = 0x80
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	ignored             category = 0xC0
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)
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// join types and additional rune information
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const (
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	joiningL = (iota + 1)
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	joiningD
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	joiningT
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	joiningR
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	//the following types are derived during processing
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	joinZWJ
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	joinZWNJ
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	joinVirama
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	numJoinTypes
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)
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func (c info) isMapped() bool {
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	return c&0x3 != 0
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}
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func (c info) category() category {
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	small := c & catSmallMask
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	if small != 0 {
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		return category(small)
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	}
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	return category(c & catBigMask)
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}
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func (c info) joinType() info {
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	if c.isMapped() {
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		return 0
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	}
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	return (c >> joinShift) & joinMask
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}
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func (c info) isModifier() bool {
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	return c&(modifier|catSmallMask) == modifier
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}
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func (c info) isViramaModifier() bool {
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	return c&(attributesMask|catSmallMask) == viramaModifier
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}
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