2.6 String Literals
1
[A
string_literal is formed
by a sequence of graphic characters (possibly none) enclosed between
two quotation marks used as string brackets. They are used to represent
operator_symbols (see
6.1),
values of a string type (see
4.2), and array
subaggregates (see
4.3.3).
{quoted
string: See string_literal} ]
Syntax
2
string_literal ::= "{
string_element}"
3
string_element ::= "" |
non_quotation_mark_graphic_character
4
A string_element
is either a pair of quotation marks (""), or a single graphic_character
other than a quotation mark.
Static Semantics
5
{sequence of characters
(of a string_literal)} The
sequence
of characters of a
string_literal is formed
from the sequence of
string_elements between
the bracketing quotation marks, in the given order, with a
string_element
that is "" becoming a single quotation mark in the sequence
of characters, and any other
string_element
being reproduced in the sequence.
6
{null string literal}
A
null string literal is a
string_literal
with no
string_elements between the quotation
marks.
7
6 An end of line cannot appear in a string_literal.
7.1/2
7 {
AI95-00285-01}
No transformation is performed on the sequence
of characters of a string_literal.
Examples
8
Examples of string
literals:
9/2
{
AI95-00433-01}
"Message of the day:"
"" --
a null string literal
" " "A" """" --
three string literals of length 1
"Characters such as $, %, and } are allowed in string literals"
"Archimedes said ""Εύρηκα"""
"Volume of cylinder (πr²h) = "
Wording Changes from Ada 83
9.a
The wording has been changed to be strictly
lexical. No mention is made of string or character values, since string_literals
are also used to represent operator_symbols,
which don't have a defined value.
9.b
The syntax is described differently.
Wording Changes from Ada 95
9.c/2
{
AI95-00285-01}
We explicitly say that the characters of a string_literal
should be used as is. In particular, no normalization or folding should
be performed on a string_literal.
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