预定义常量
 
  
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INTL_MAX_LOCALE_LEN
     (integer)
    
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      Limit on locale length, set to 80 in PHP code. Locale names longer 
      than this limit will not be accepted.
     
    
 
   
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IDNA_DEFAULT
     (integer)
    
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      Prohibit processing of unassigned codepoints in the input for IDN
      functions and do not check if the input conforms to domain name ASCII rules.
     
    
 
   
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IDNA_ALLOW_UNASSIGNED
     (integer)
    
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      Allow processing of unassigned codepoints in the input for IDN functions.
     
    
 
   
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IDNA_USE_STD3_RULES
     (integer)
    
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      Check if the input for IDN functions conforms to domain name ASCII rules.
     
    
 
   
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IDNA_CHECK_BIDI
     (integer)
    
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      Check whether the input conforms to the BiDi rules.
      Ignored by the IDNA2003 implementation, which always performs this check.
     
    
 
   
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IDNA_CHECK_CONTEXTJ
     (integer)
    
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      Check whether the input conforms to the CONTEXTJ rules.
      Ignored by the IDNA2003 implementation, as this check is new in IDNA2008.
     
    
 
   
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IDNA_NONTRANSITIONAL_TO_ASCII
     (integer)
    
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      Option for nontransitional processing in
       idn_to_ascii(). Transitional processing is activated
      by default. This option is ignored by the IDNA2003 implementation.
     
    
 
   
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IDNA_NONTRANSITIONAL_TO_UNICODE
     (integer)
    
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      Option for nontransitional processing in
       idn_to_utf8(). Transitional processing is activated
      by default. This option is ignored by the IDNA2003 implementation.
     
    
 
   
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INTL_IDNA_VARIANT_2003
     (integer)
    
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      Use IDNA 2003 algorithm in  idn_to_utf8() and
       idn_to_ascii(). This is the default.
     
    
 
   
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INTL_IDNA_VARIANT_UTS46
     (integer)
    
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      Use UTS #46 algorithm in  idn_to_utf8() and
       idn_to_ascii().
     
    
 
   
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IDNA_ERROR_EMPTY_LABEL (integer)
    
    
     IDNA_ERROR_LABEL_TOO_LONG (integer)
    
    
     IDNA_ERROR_DOMAIN_NAME_TOO_LONG (integer)
    
    
     IDNA_ERROR_LEADING_HYPHEN (integer)
    
    
     IDNA_ERROR_TRAILING_HYPHEN (integer)
    
    
     IDNA_ERROR_HYPHEN_3_4 (integer)
    
    
     IDNA_ERROR_LEADING_COMBINING_MARK
     (integer)
    
    
     IDNA_ERROR_DISALLOWED (integer)
    
    
     IDNA_ERROR_PUNYCODE (integer)
    
    
     IDNA_ERROR_LABEL_HAS_DOT (integer)
    
    
     IDNA_ERROR_INVALID_ACE_LABEL (integer)
    
    
     IDNA_ERROR_BIDI (integer)
    
    
     IDNA_ERROR_CONTEXTJ (integer)
    
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      Errors reported in a bitset returned by the UTS #46 algorithm in
       idn_to_utf8() and
       idn_to_ascii().