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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
5 An end of line cannot
appear in a string_literal.
Examples
8
Examples of string
literals:
9
"Message of the day:"
"" -- a null string literal
" " "A" """" -- three string literals of length 1
"Characters such as $, %, and } are allowed in string literals"
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.
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