gcc/ada/s-utf_32.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --                        S Y S T E M . U T F _ 3 2                         --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 2005-2012, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
  17 --                                                                          --
  18 -- As a special exception under Section 7 of GPL version 3, you are granted --
  19 -- additional permissions described in the GCC Runtime Library Exception,   --
  20 -- version 3.1, as published by the Free Software Foundation.               --
  21 --                                                                          --
  22 -- You should have received a copy of the GNU General Public License and    --
  23 -- a copy of the GCC Runtime Library Exception along with this program;     --
  24 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  25 -- <http://www.gnu.org/licenses/>.                                          --
  26 --                                                                          --
  27 -- GNAT was originally developed  by the GNAT team at  New York University. --
  28 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31
  32 --  This package is an internal package that provides basic character
  33 --  classification capabilities needed by the compiler for handling full
  34 --  32-bit wide wide characters. We avoid the use of the actual type
  35 --  Wide_Wide_Character, since we want to use these routines in the compiler
  36 --  itself, and we want to be able to compile the compiler with old versions
  37 --  of GNAT that did not implement Wide_Wide_Character.
  38
  39 --  System.UTF_32 should not be directly used from an application program, but
  40 --  an equivalent package GNAT.UTF_32 can be used directly and provides exactly
  41 --  the same services. The reason this package is in System is so that it can
  42 --  with'ed by other packages in the Ada and System hierarchies.
  43
  44 pragma Compiler_Unit;
  45
  46 package System.UTF_32 is
  47    pragma Pure;
  48
  49    type UTF_32 is range 0 .. 16#7FFF_FFFF#;
  50    --  So far, the only defined character codes are in 0 .. 16#01_FFFF#
  51
  52    --  The following type defines the categories from the unicode definitions.
  53    --  The one addition we make is Fe, which represents the characters FFFE
  54    --  and FFFF in any of the planes.
  55
  56    type Category is (
  57      Cc,   --  Other, Control
  58      Cf,   --  Other, Format
  59      Cn,   --  Other, Not Assigned
  60      Co,   --  Other, Private Use
  61      Cs,   --  Other, Surrogate
  62      Ll,   --  Letter, Lowercase
  63      Lm,   --  Letter, Modifier
  64      Lo,   --  Letter, Other
  65      Lt,   --  Letter, Titlecase
  66      Lu,   --  Letter, Uppercase
  67      Mc,   --  Mark, Spacing Combining
  68      Me,   --  Mark, Enclosing
  69      Mn,   --  Mark, Nonspacing
  70      Nd,   --  Number, Decimal Digit
  71      Nl,   --  Number, Letter
  72      No,   --  Number, Other
  73      Pc,   --  Punctuation, Connector
  74      Pd,   --  Punctuation, Dash
  75      Pe,   --  Punctuation, Close
  76      Pf,   --  Punctuation, Final quote
  77      Pi,   --  Punctuation, Initial quote
  78      Po,   --  Punctuation, Other
  79      Ps,   --  Punctuation, Open
  80      Sc,   --  Symbol, Currency
  81      Sk,   --  Symbol, Modifier
  82      Sm,   --  Symbol, Math
  83      So,   --  Symbol, Other
  84      Zl,   --  Separator, Line
  85      Zp,   --  Separator, Paragraph
  86      Zs,   --  Separator, Space
  87      Fe);  --  relative position FFFE/FFFF in any plane
  88
  89    function Get_Category (U : UTF_32) return Category;
  90    --  Given a UTF32 code, returns corresponding Category, or Cn if
  91    --  the code does not have an assigned unicode category.
  92
  93    --  The following functions perform category tests corresponding to lexical
  94    --  classes defined in the Ada standard. There are two interfaces for each
  95    --  function. The second takes a Category (e.g. returned by Get_Category).
  96    --  The first takes a UTF_32 code. The form taking the UTF_32 code is
  97    --  typically more efficient than calling Get_Category, but if several
  98    --  different tests are to be performed on the same code, it is more
  99    --  efficient to use Get_Category to get the category, then test the
 100    --  resulting category.
 101
 102    function Is_UTF_32_Letter (U : UTF_32)   return Boolean;
 103    function Is_UTF_32_Letter (C : Category) return Boolean;
 104    pragma Inline (Is_UTF_32_Letter);
 105    --  Returns true iff U is a letter that can be used to start an identifier,
 106    --  or if C is one of the corresponding categories, which are the following:
 107    --    Letter, Uppercase (Lu)
 108    --    Letter, Lowercase (Ll)
 109    --    Letter, Titlecase (Lt)
 110    --    Letter, Modifier  (Lm)
 111    --    Letter, Other     (Lo)
 112    --    Number, Letter    (Nl)
 113
 114    function Is_UTF_32_Digit (U : UTF_32)   return Boolean;
 115    function Is_UTF_32_Digit (C : Category) return Boolean;
 116    pragma Inline (Is_UTF_32_Digit);
 117    --  Returns true iff U is a digit that can be used to extend an identifier,
 118    --  or if C is one of the corresponding categories, which are the following:
 119    --    Number, Decimal_Digit (Nd)
 120
 121    function Is_UTF_32_Line_Terminator (U : UTF_32) return Boolean;
 122    pragma Inline (Is_UTF_32_Line_Terminator);
 123    --  Returns true iff U is an allowed line terminator for source programs,
 124    --  if U is in the category Zp (Separator, Paragraph), or Zl (Separator,
 125    --  Line), or if U is a conventional line terminator (CR, LF, VT, FF).
 126    --  There is no category version for this function, since the set of
 127    --  characters does not correspond to a set of Unicode categories.
 128
 129    function Is_UTF_32_Mark (U : UTF_32)   return Boolean;
 130    function Is_UTF_32_Mark (C : Category) return Boolean;
 131    pragma Inline (Is_UTF_32_Mark);
 132    --  Returns true iff U is a mark character which can be used to extend an
 133    --  identifier, or if C is one of the corresponding categories, which are
 134    --  the following:
 135    --    Mark, Non-Spacing (Mn)
 136    --    Mark, Spacing Combining (Mc)
 137
 138    function Is_UTF_32_Other (U : UTF_32)   return Boolean;
 139    function Is_UTF_32_Other (C : Category) return Boolean;
 140    pragma Inline (Is_UTF_32_Other);
 141    --  Returns true iff U is an other format character, which means that it
 142    --  can be used to extend an identifier, but is ignored for the purposes of
 143    --  matching of identifiers, or if C is one of the corresponding categories,
 144    --  which are the following:
 145    --    Other, Format (Cf)
 146
 147    function Is_UTF_32_Punctuation (U : UTF_32)   return Boolean;
 148    function Is_UTF_32_Punctuation (C : Category) return Boolean;
 149    pragma Inline (Is_UTF_32_Punctuation);
 150    --  Returns true iff U is a punctuation character that can be used to
 151    --  separate pieces of an identifier, or if C is one of the corresponding
 152    --  categories, which are the following:
 153    --    Punctuation, Connector (Pc)
 154
 155    function Is_UTF_32_Space (U : UTF_32)   return Boolean;
 156    function Is_UTF_32_Space (C : Category) return Boolean;
 157    pragma Inline (Is_UTF_32_Space);
 158    --  Returns true iff U is considered a space to be ignored, or if C is one
 159    --  of the corresponding categories, which are the following:
 160    --    Separator, Space (Zs)
 161
 162    function Is_UTF_32_Non_Graphic (U : UTF_32)   return Boolean;
 163    function Is_UTF_32_Non_Graphic (C : Category) return Boolean;
 164    pragma Inline (Is_UTF_32_Non_Graphic);
 165    --  Returns true iff U is considered to be a non-graphic character, or if C
 166    --  is one of the corresponding categories, which are the following:
 167    --    Other, Control (Cc)
 168    --    Other, Private Use (Co)
 169    --    Other, Surrogate (Cs)
 170    --    Separator, Line (Zl)
 171    --    Separator, Paragraph (Zp)
 172    --    FFFE or FFFF positions in any plane (Fe)
 173    --
 174    --  Note that the Ada category format effector is subsumed by the above
 175    --  list of Unicode categories.
 176    --
 177    --  Note that Other, Unassigned (Cn) is quite deliberately not included
 178    --  in the list of categories above. This means that should any of these
 179    --  code positions be defined in future with graphic characters they will
 180    --  be allowed without a need to change implementations or the standard.
 181    --
 182    --  Note that Other, Format (Cf) is also quite deliberately not included
 183    --  in the list of categories above. This means that these characters can
 184    --  be included in character and string literals.
 185
 186    --  The following function is used to fold to upper case, as required by
 187    --  the Ada 2005 standard rules for identifier case folding. Two
 188    --  identifiers are equivalent if they are identical after folding all
 189    --  letters to upper case using this routine. A corresponding routine to
 190    --  fold to lower case is also provided.
 191
 192    function UTF_32_To_Lower_Case (U : UTF_32) return UTF_32;
 193    pragma Inline (UTF_32_To_Lower_Case);
 194    --  If U represents an upper case letter, returns the corresponding lower
 195    --  case letter, otherwise U is returned unchanged. The folding rule is
 196    --  simply that if the code corresponds to a 10646 entry whose name contains
 197    --  the string CAPITAL LETTER, and there is a corresponding entry whose name
 198    --  is the same but with CAPITAL LETTER replaced by SMALL LETTER, then the
 199    --  code is folded to this SMALL LETTER code. Otherwise the input code is
 200    --  returned unchanged.
 201
 202    function UTF_32_To_Upper_Case (U : UTF_32) return UTF_32;
 203    pragma Inline (UTF_32_To_Upper_Case);
 204    --  If U represents a lower case letter, returns the corresponding lower
 205    --  case letter, otherwise U is returned unchanged. The folding rule is
 206    --  simply that if the code corresponds to a 10646 entry whose name contains
 207    --  the string SMALL LETTER, and there is a corresponding entry whose name
 208    --  is the same but with SMALL LETTER replaced by CAPITAL LETTER, then the
 209    --  code is folded to this CAPITAL LETTER code. Otherwise the input code is
 210    --  returned unchanged.
 211
 212 end System.UTF_32;