A.1 The Package Standard
1
This clause outlines the specification of the package 
Standard containing all predefined identifiers in the language. 
{unspecified 
[partial]} The corresponding package body 
is not specified by the language.
 
2
The operators that are predefined for the types declared 
in the package Standard are given in comments since they are implicitly 
declared. 
{italics (pseudo-names of anonymous 
types)} Italics are used for pseudo-names 
of anonymous types (such as 
root_real) and for undefined information 
(such as 
implementation-defined). 
 
2.a
Ramification: All of the predefined operators 
are of convention Intrinsic. 
Static Semantics
3
The library package 
Standard has the following declaration: 
3.a
Implementation defined: The names and 
characteristics of the numeric subtypes declared in the visible part 
of package Standard.
4
package Standard 
is
   pragma Pure(Standard);
 
5
   type Boolean 
is (False, True);
 
6
   -- The predefined relational operators for this type are as follows:
7/1
{
8652/0028} 
{
AI95-00145-01} 
   -- 
function "="   (Left, Right : Boolean
'Base) 
return Boolean;
   -- 
function "/="  (Left, Right : Boolean
'Base) 
return Boolean;
   -- 
function "<"   (Left, Right : Boolean
'Base) 
return Boolean;
   -- 
function "<="  (Left, Right : Boolean
'Base) 
return Boolean;
   -- 
function ">"   (Left, Right : Boolean
'Base) 
return Boolean;
   -- 
function ">="  (Left, Right : Boolean
'Base) 
return Boolean;
 
8
   -- The predefined logical operators and the predefined logical
   -- negation operator are as follows:
9/1
{
8652/0028} 
{
AI95-00145-01} 
   -- 
function "
and" (Left, Right : Boolean
'Base) 
return Boolean
'Base;
   -- 
function "
or"  (Left, Right : Boolean
'Base) 
return Boolean
'Base;
   -- 
function "
xor" (Left, Right : Boolean
'Base) 
return Boolean
'Base;
 
10/1
11/2
{
AI95-00434-01} 
   --
 The integer type root_integer and the is predefined.
   --
 The corresponding universal type is universal_integer are predefined. 
12
   type Integer 
is range implementation-defined;
 
13
   subtype Natural  
is Integer 
range 0 .. Integer'Last;
   
subtype Positive 
is Integer 
range 1 .. Integer'Last;
 
14
   -- The predefined operators for type Integer are as follows:
15
   -- function "="  (Left, Right : Integer'Base) return Boolean;
   -- function "/=" (Left, Right : Integer'Base) return Boolean;
   -- function "<"  (Left, Right : Integer'Base) return Boolean;
   -- function "<=" (Left, Right : Integer'Base) return Boolean;
   -- function ">"  (Left, Right : Integer'Base) return Boolean;
   -- function ">=" (Left, Right : Integer'Base) return Boolean;
16
   -- function "+"   (Right : Integer'Base) return Integer'Base;
   -- function "-"   (Right : Integer'Base) return Integer'Base;
   -- function "abs" (Right : Integer'Base) return Integer'Base;
17
   -- function "+"   (Left, Right : Integer'Base) return Integer'Base;
   -- function "-"   (Left, Right : Integer'Base) return Integer'Base;
   -- function "*"   (Left, Right : Integer'Base) return Integer'Base;
   -- function "/"   (Left, Right : Integer'Base) return Integer'Base;
   -- function "rem" (Left, Right : Integer'Base) return Integer'Base;
   -- function "mod" (Left, Right : Integer'Base) return Integer'Base;
18
   -- function "**"  (Left : Integer'Base; Right : Natural)
   --                  return Integer'Base;
19
   -- The specification of each operator for the type
   -- root_integer, or for any additional predefined integer
   -- type, is obtained by replacing Integer by the name of the type
   -- in the specification of the corresponding operator of the type
   -- Integer. The right operand of the exponentiation operator
   -- remains as subtype Natural.
20/2
{
AI95-00434-01} 
   --
 The floating point type root_real and the is predefined.
   --
 The corresponding universal type is universal_real are predefined. 
21
   type Float 
is digits implementation-defined;
 
22
   -- The predefined operators for this type are as follows:
23
   -- function "="   (Left, Right : Float) return Boolean;
   -- function "/="  (Left, Right : Float) return Boolean;
   -- function "<"   (Left, Right : Float) return Boolean;
   -- function "<="  (Left, Right : Float) return Boolean;
   -- function ">"   (Left, Right : Float) return Boolean;
   -- function ">="  (Left, Right : Float) return Boolean;
24
   -- function "+"   (Right : Float) return Float;
   -- function "-"   (Right : Float) return Float;
   -- function "abs" (Right : Float) return Float;
25
   -- function "+"   (Left, Right : Float) return Float;
   -- function "-"   (Left, Right : Float) return Float;
   -- function "*"   (Left, Right : Float) return Float;
   -- function "/"   (Left, Right : Float) return Float;
26
   -- function "**"  (Left : Float; Right : Integer'Base) return Float;
27
   -- The specification of each operator for the type root_real, or for
   -- any additional predefined floating point type, is obtained by
   -- replacing Float by the name of the type in the specification of the
   -- corresponding operator of the type Float.
28
   -- In addition, the following operators are predefined for the root
   -- numeric types:
29
   function "*" (Left : root_integer; Right : root_real)
     return root_real;
30
   function "*" (Left : root_real;    Right : root_integer)
     return root_real;
31
   function "/" (Left : root_real;    Right : root_integer)
     return root_real;
32
   -- The type universal_fixed is predefined.
   -- The only multiplying operators defined between
   -- fixed point types are
33
   function "*" (Left : universal_fixed; Right : universal_fixed)
     return universal_fixed;
34
   function "/" (Left : universal_fixed; Right : universal_fixed)
     return universal_fixed;
34.1/2
{
AI95-00230-01} 
   -- The type universal_access is predefined.
   -- The following equality operators are predefined: 
34.2/2
{
AI95-00230-01} 
   function "="  (Left, Right: universal_access) return Boolean;
   function "/=" (Left, Right: universal_access) return Boolean; 
35/2
{
AI95-00415-01} 
      --
 The declaration of type Character is based on the standard ISO 8859-1 character set.
      --
 There are no character literals corresponding to the positions for control characters.
      --
 They are indicated in italics in this definition. See 3.5.2.
   type Character 
is
     (
nul,     
soh,   
stx,    
etx,      
eot,   
enq,    
ack,   
bel,   --
0 (16#00#) .. 7 (16#07#)
      bs,      
ht,    
lf,     
vt,       
ff,    
cr,     
so,    
si,    --
8 (16#08#) .. 15 (16#0F#)
      dle,     
dc1,   
dc2,    
dc3,      
dc4,   
nak,    
syn,   
etb,   --
16 (16#10#) .. 23 (16#17#)
      can,     
em,    
sub,    
esc,      
fs,    
gs,     
rs,    
us,    --
24 (16#18#) .. 31 (16#1F#)
      ' ',     '!',   '"',    '#',      '$',   '%',    '&',   ''',   --
32 (16#20#) .. 39 (16#27#)
      '(',     ')',   '*',    '+',      ',',   '-',    '.',   '/',   --
40 (16#28#) .. 47 (16#2F#)
      '0',     '1',   '2',    '3',      '4',   '5',    '6',   '7',   --
48 (16#30#) .. 55 (16#37#)
      '8',     '9',   ':',    ';',      '<',   '=',    '>',   '?',   --
56 (16#38#) .. 63 (16#3F#)
      '@',     'A',   'B',    'C',      'D',   'E',    'F',   'G',   --
64 (16#40#) .. 71 (16#47#)
      'H',     'I',   'J',    'K',      'L',   'M',    'N',   'O',   --
72 (16#48#) .. 79 (16#4F#)
      'P',     'Q',   'R',    'S',      'T',   'U',    'V',   'W',   --
80 (16#50#) .. 87 (16#57#)
      'X',     'Y',   'Z',    '[',      '\',   ']',    '^',   '_',   --
88 (16#58#) .. 95 (16#5F#)
      '`',     'a',   'b',    'c',      'd',   'e',    'f',   'g',   --
96 (16#60#) .. 103 (16#67#)
      'h',     'i',   'j',    'k',      'l',   'm',    'n',   'o',   --
104 (16#68#) .. 111 (16#6F#)
      'p',     'q',   'r',    's',      't',   'u',    'v',   'w',   --
112 (16#70#) .. 119 (16#77#)
      'x',     'y',   'z',    '{',      '|',   '}',    '~',   
del,   --
120 (16#78#) .. 127 (16#7F#)
      reserved_128,   
reserved_129,     
bph,   
nbh,                  --
128 (16#80#) .. 131 (16#83#)
      reserved_132,   
nel,    
ssa,      
esa,                         --
132 (16#84#) .. 135 (16#87#)
      hts,     
htj,   
vts,    
pld,      
plu,   
ri,     
ss2,   
ss3,   --
136 (16#88#) .. 143 (16#8F#)
      dcs,     
pu1,   
pu2,    
sts,      
cch,   
mw,     
spa,   
epa,   --
144 (16#90#) .. 151 (16#97#)
      sos,     
reserved_153,  
sci,      
csi,                         --
152 (16#98#) .. 155 (16#9B#)
      st,      
osc,   
pm,     
apc,                                   --
156 (16#9C#) .. 159 (16#9F#)
      ' ',     '¡',   '¢',    '£',      '¤',   '¥',    '¦',   '§',   --
160 (16#A0#) .. 167 (16#A7#)
      '¨',     '©',   'ª',    '«',      '¬',   '',    '®',   '¯',   --
168 (16#A8#) .. 175 (16#AF#)
      '°',     '±',   '²',    '³',      '´',   'µ',    '¶',   '·',   --
176 (16#B0#) .. 183 (16#B7#)
      '¸',     '¹',   'º',    '»',      '¼',   '½',    '¾',   '¿',   --
184 (16#B8#) .. 191 (16#BF#)
      'À',     'Á',   'Â',    'Ã',      'Ä',   'Å',    'Æ',   'Ç',   --
192 (16#C0#) .. 199 (16#C7#)
      'È',     'É',   'Ê',    'Ë',      'Ì',   'Í',    'Î',   'Ï',   --
200 (16#C8#) .. 207 (16#CF#)
      'Ð',     'Ñ',   'Ò',    'Ó',      'Ô',   'Õ',    'Ö',   '×',   --
208 (16#D0#) .. 215 (16#D7#)
      'Ø',     'Ù',   'Ú',    'Û',      'Ü',   'Ý',    'Þ',   'ß',   --
216 (16#D8#) .. 223 (16#DF#)
      'à',     'á',   'â',    'ã',      'ä',   'å',    'æ',   'ç',   --
224 (16#E0#) .. 231 (16#E7#)
      'è',     'é',   'ê',    'ë',      'ì',   'í',    'î',   'ï',   --
232 (16#E8#) .. 239 (16#EF#)
      'ð',     'ñ',   'ò',    'ó',      'ô',   'õ',    'ö',   '÷',   --
240 (16#F0#) .. 247 (16#F7#)
      'ø',     'ù',   'ú',    'û',      'ü',   'ý',    'þ',   'ÿ'
);, --
248 (16#F8#) .. 255 (16#FF#) 
36
   -- The predefined operators for the type Character are the same as for
   -- any enumeration type.
36.1/2
{
AI95-00395-01} 
   --
 The declaration of type Wide_Character is based on the standard ISO/IEC ISO 10646:2003 BMP character set.
   --
 set. The first 256 positions have the same contents as type Character. See 3.5.2.
   type Wide_Character 
is (
nul, 
soh ... 
Hex_0000FFFE FFFE, 
Hex_0000FFFF FFFF);
 
36.2/2
{
AI95-00285-01} 
{
AI95-00395-01} 
   -- The declaration of type Wide_Wide_Character is based on the full
   -- ISO/IEC 10646:2003 character set. The first 65536 positions have the
   -- same contents as type Wide_Character. See 3.5.2.
   type Wide_Wide_Character is (nul, soh ... Hex_7FFFFFFE, Hex_7FFFFFFF);
   for Wide_Wide_Character'Size use 32; 
36.3/2
   package ASCII 
is ... 
end ASCII;  --
Obsolescent; see J.5
{ASCII (package physically nested within 
the declaration of Standard)} 
 
37
   --
 Predefined string types:
   type String 
is array(Positive 
range <>) 
of Character;
   
pragma Pack(String);
 
38
   -- The predefined operators for this type are as follows:
39
   --     function "="  (Left, Right: String) return Boolean;
   --     function "/=" (Left, Right: String) return Boolean;
   --     function "<"  (Left, Right: String) return Boolean;
   --     function "<=" (Left, Right: String) return Boolean;
   --     function ">"  (Left, Right: String) return Boolean;
   --     function ">=" (Left, Right: String) return Boolean;
40
   --     function "&" (Left: String;    Right: String)    return String;
   --     function "&" (Left: Character; Right: String)    return String;
   --     function "&" (Left: String;    Right: Character) return String;
   --     function "&" (Left: Character; Right: Character) return String;
41
   type Wide_String 
is array(Positive 
range <>) 
of Wide_Character;
   
pragma Pack(Wide_String);
 
42
   -- The predefined operators for this type correspond to those for String.
42.1/2
{
AI95-00285-01} 
   type Wide_Wide_String is array (Positive range <>)
     of Wide_Wide_Character;
   pragma Pack (Wide_Wide_String); 
42.2/2
{
AI95-00285-01} 
   -- The predefined operators for this type correspond to those for String. 
43
   type Duration 
is delta implementation-defined range implementation-defined;
 
44
      -- The predefined operators for the type Duration are the same as for
      -- any fixed point type.
45
   -- The predefined exceptions:
46
   Constraint_Error: 
exception;
   
Program_Error   : 
exception;
   
Storage_Error   : 
exception;
   
Tasking_Error   : 
exception;
 
47
end Standard;
48
Standard has no private part. 
48.a
Reason: This is important for portability. 
All library packages are children of Standard, and if Standard had a 
private part then it would be visible to all of them. 
49/2
 {
AI95-00285-01} 
In each of the types Character
, and Wide_Character
, and Wide_Wide_Character, 
the character literals for the space character (position 32) and the 
non-breaking space character (position 160) correspond to different values. 
Unless indicated otherwise, each occurrence of the character literal 
' ' in this International Standard refers to the space character. Similarly, 
the character literals for hyphen (position 45) and soft hyphen (position 
173) correspond to different values. Unless indicated otherwise, each 
occurrence of the character literal '–' in this International Standard 
refers to the hyphen character. 
 
Dynamic Semantics
50
{elaboration (package_body 
of Standard) [partial]} Elaboration of 
the body of Standard has no effect. 
 
50.a
Implementation Permissions
51
An implementation may provide additional predefined 
integer types and additional predefined floating point types. Not all 
of these types need have names. 
51.a
To be honest: An implementation may add 
representation items to package Standard, for example to specify the 
internal codes of type Boolean, or the Small of type Duration.
Implementation Advice
52
If an implementation provides additional named predefined 
integer types, then the names should end with “Integer” as 
in “Long_Integer”. If an implementation provides additional 
named predefined floating point types, then the names should end with 
“Float” as in “Long_Float”. 
52.a/2
Implementation Advice: 
If an implementation provides additional 
named predefined integer types, then the names should end with “Integer”. 
If an implementation provides additional named predefined floating point 
types, then the names should end with “Float”.
53
1  Certain aspects of the predefined entities 
cannot be completely described in the language itself. For example, although 
the enumeration type Boolean can be written showing the two enumeration 
literals False and True, the short-circuit control forms cannot be expressed 
in the language.
54
2  As explained in 
8.1, 
“
Declarative Region” and 
10.1.4, 
“
The Compilation Process”, the 
declarative region of the package Standard encloses every library unit 
and consequently the main subprogram; the declaration of every library 
unit is assumed to occur within this declarative region. 
Library_items 
are assumed to be ordered in such a way that there are no forward semantic 
dependences. However, as explained in 
8.3, 
“
Visibility”, the only library 
units that are visible within a given compilation unit are the library 
units named by all 
with_clauses that apply 
to the given unit, and moreover, within the declarative region of a given 
library unit, that library unit itself.
 
55
3  If all block_statements 
of a program are named, then the name of each program unit can always 
be written as an expanded name starting with Standard (unless Standard 
is itself hidden). The name of a library unit cannot be a homograph of 
a name (such as Integer) that is already declared in Standard.
56
4  The exception Standard.Numeric_Error 
is defined in 
J.6. 
 
56.a
Discussion: The declaration of Natural 
needs to appear between the declaration of Integer and the (implicit) 
declaration of the "**" operator for Integer, because a formal 
parameter of "**" is of subtype Natural. This would be impossible 
in normal code, because the implicit declarations for a type occur immediately 
after the type declaration, with no possibility of intervening explicit 
declarations. But we're in Standard, and Standard is somewhat magic anyway.
56.b
Using Natural as the subtype of the formal of 
"**" seems natural; it would be silly to have a textual rule 
about Constraint_Error being raised when there is a perfectly good subtype 
that means just that. Furthermore, by not using Integer for that formal, 
it helps remind the reader that the exponent remains Natural even when 
the left operand is replaced with the derivative of Integer. It doesn't 
logically imply that, but it's still useful as a reminder.
56.c
In any case, declaring these general-purpose 
subtypes of Integer close to Integer seems more readable than declaring 
them much later. 
Extensions to Ada 83
56.d
{
extensions to Ada 83} 
Package 
Standard is declared to be pure. 
 
56.e
Discussion: The introduction of the types 
Wide_Character and Wide_String is not an Ada 95 extension to Ada 83, 
since ISO WG9 has approved these as an authorized extension of the original 
Ada 83 standard that is part of that standard. 
Wording Changes from Ada 83
56.f
Numeric_Error is made obsolescent.
56.g
The declarations of Natural and Positive are 
moved to just after the declaration of Integer, so that "**" 
can refer to Natural without a forward reference. There's no real need 
to move Positive, too — it just came along for the ride. 
Extensions to Ada 95
56.h/2
{
AI95-00285-01} 
{extensions to Ada 95} Types 
Wide_Wide_Character and Wide_Wide_String are new.  
56.i/2
Discussion: The 
inconsistencies associated with these types are documented in 3.5.2 
and 3.6.3.  
56.j/2
{
AI95-00230-01} 
Type universal_access and the equality operations 
for it are new.  
Wording Changes from Ada 95
56.k/2
{
8652/0028} 
{
AI95-00145-01} 
Corrigendum: Corrected the parameter type 
for the Boolean operators declared in Standard..