F.3.2 Edited Output Generation
Dynamic Semantics
The contents of an
edited output string are based on:
A value, Item, of some decimal type Num,
An expanded picture String Pic_String,
A Boolean value, Blank_When_Zero,
A Currency string,
A Fill character,
A Separator character, and
A Radix_Mark character.
The combination of a True value for Blank_When_Zero
and a '*' character in Pic_String is inconsistent; no edited output string
is defined.
Reason: {
AI95-00114-01}
Such a Pic_String is invalid, and any attempt to use such a string will
raise Picture_Error.
A layout error is identified in the rules below if
leading non-zero digits of Item, character values of the Currency string,
or a negative sign would be truncated; in such cases no edited output
string is defined.
The edited output string has lower bound 1 and upper
bound N where N = Pic_String'Length + Currency_Length_Adjustment –
Radix_Adjustment, and
Currency_Length_Adjustment = Currency'Length –
1 if there is some occurrence of '$' in Pic_String, and 0 otherwise.
Radix_Adjustment = 1 if there is an occurrence
of 'V' or 'v' in Pic_Str, and 0 otherwise.
{displayed
magnitude (of a decimal value)} Let the
magnitude of Item be expressed as a base-10 number I
p···I
1.F
1···F
q,
called the
displayed magnitude of Item, where:
q = Min(Max(Num'Scale, 0), n) where n is 0 if Pic_String
has no radix and is otherwise the number of
digit positions following radix in Pic_String,
where a digit position corresponds to an occurrence of '9', a zero_suppression_char
(for an all_zero_suppression_number), a currency_char
(for an all_currency_number), or a sign_char
(for an all_sign_number).
Ip
/= 0 if p>0.
If n < Num'Scale, then the above number is the
result of rounding (away from 0 if exactly midway between values).
If Blank_When_Zero = True and the displayed magnitude
of Item is zero, then the edited output string comprises all space character
values. Otherwise, the picture String is treated as a sequence of instances
of syntactic categories based on the rules in
F.3.1,
and the edited output string is the concatenation of string values derived
from these categories according to the following mapping rules.
Table F-1 shows the mapping from a sign control symbol
to a corresponding character or string in the edited output. In the columns
showing the edited output, a lower-case 'b' represents the space character.
If there is no sign control symbol but the value of Item is negative,
a layout error occurs and no edited output string is produced.
Table F-1: Edited Output for Sign Control Symbols
| Sign Control Symbol | Edited
Output for
Non-Negative Number | Edited Output for
Negative Number
|
|---|
| '+' | '+' | '–'
|
| '–' | 'b' | '–'
|
| '<' | 'b' | '('
|
| '>' | 'b' | ')'
|
| "CR" | "bb" | "CR"
|
| "DB" | "bb" | "DB"
|
An instance of fixed_LHS_sign
maps to a character as shown in Table F-1.
An instance of fixed_$_char
maps to Currency.
An instance of direct_insertion
maps to Separator if direct_insertion = '_',
and to the direct_insertion Character otherwise.
An instance of number
maps to a string integer_part & radix_part & fraction_part
where:
The string for integer_part is obtained
as follows:
1.
Occurrences of '9' in fore_digits of number
are replaced from right to left with the decimal digit character values
for I1,
..., Ip,
respectively.
2.
Each occurrence of '9' in fore_digits to the
left of the leftmost '9' replaced according to rule 1 is replaced with
'0'.
3.
If p exceeds the number of occurrences of '9' in fore_digits
of number, then the excess leftmost digits
are eligible for use in the mapping of an instance of zero_suppression,
floating_LHS_sign, floating_$_currency,
or floating_#_currency to the left of number;
if there is no such instance, then a layout error occurs and no edited
output string is produced.
The radix_part
is:
"" if number
does not include a radix, if radix
= 'V', or if radix = 'v'
Radix_Mark if number
includes '.' as radix
The string for fraction_part
is obtained as follows:
1.
Occurrences of '9' in aft_digits of number
are replaced from left to right with the decimal digit character values
for F1,
... Fq.
2.
Each occurrence of '9' in aft_digits to the
right of the rightmost '9' replaced according to rule 1 is replaced by
'0'.
An instance of zero_suppression
maps to the string obtained as follows:
1.
The rightmost 'Z', 'z', or '*' Character values are replaced with the
excess digits (if any) from the integer_part of the mapping of
the number to the right of the zero_suppression
instance,
2.
A context_sensitive_insertion Character is
replaced as though it were a direct_insertion
Character, if it occurs to the right of some 'Z', 'z', or '*' in zero_suppression
that has been mapped to an excess digit,
3.
Each Character to the left of the leftmost Character replaced according
to rule 1 above is replaced by:
the space character if the zero
suppression Character is 'Z' or 'z', or
the Fill character if the zero suppression
Character is '*'.
4.
A layout error occurs if some excess digits remain after all 'Z', 'z',
and '*' Character values in zero_suppression
have been replaced via rule 1; no edited output string is produced.
An instance of RHS_sign
maps to a character or string as shown in Table F-1.
An instance of floating_LHS_sign
maps to the string obtained as follows.
1.
Up to all but one of the rightmost LHS_Sign
Character values are replaced by the excess digits (if any) from the
integer_part of the mapping of the number
to the right of the floating_LHS_sign instance.
2.
The next Character to the left is replaced with the character given by
the entry in Table F-1 corresponding to the LHS_Sign
Character.
3.
A context_sensitive_insertion Character is
replaced as though it were a direct_insertion
Character, if it occurs to the right of the leftmost LHS_Sign
character replaced according to rule 1.
4.
Any other Character is replaced by the space character..
5.
A layout error occurs if some excess digits remain after replacement
via rule 1; no edited output string is produced.
An instance of fixed_#_currency
maps to the Currency string with n space character values concatenated
on the left (if the instance does not follow a radix)
or on the right (if the instance does follow a radix),
where n is the difference between the length of the fixed_#_currency
instance and Currency'Length. A layout error occurs if Currency'Length
exceeds the length of the fixed_#_currency
instance; no edited output string is produced.
An instance of floating_$_currency
maps to the string obtained as follows:
1.
Up to all but one of the rightmost '$' Character values are replaced
with the excess digits (if any) from the integer_part of the mapping
of the number to the right of the floating_$_currency
instance.
2.
The next Character to the left is replaced by the Currency string.
3.
A context_sensitive_insertion Character is
replaced as though it were a direct_insertion
Character, if it occurs to the right of the leftmost '$' Character replaced
via rule 1.
4.
Each other Character is replaced by the space character.
5.
A layout error occurs if some excess digits remain after replacement
by rule 1; no edited output string is produced.
An instance of floating_#_currency
maps to the string obtained as follows:
1.
Up to all but one of the rightmost '#' Character values are replaced
with the excess digits (if any) from the integer_part of the mapping
of the number to the right of the floating_#_currency
instance.
2.
The substring whose last Character occurs at the position immediately
preceding the leftmost Character replaced via rule 1, and whose length
is Currency'Length, is replaced by the Currency string.
3.
A context_sensitive_insertion Character is
replaced as though it were a direct_insertion
Character, if it occurs to the right of the leftmost '#' replaced via
rule 1.
4.
Any other Character is replaced by the space character.
5.
A layout error occurs if some excess digits remain after replacement
rule 1, or if there is no substring with the required length for replacement
rule 2; no edited output string is produced.
An instance of all_zero_suppression_number
maps to:
a string of all spaces if the displayed magnitude
of Item is zero, the zero_suppression_char
is 'Z' or 'z', and the instance of all_zero_suppression_number
does not have a radix at its last character
position;
a string containing the Fill character in each
position except for the character (if any) corresponding to radix,
if zero_suppression_char = '*' and the displayed
magnitude of Item is zero;
otherwise, the same result as if each zero_suppression_char
in all_zero_suppression_aft were '9', interpreting
the instance of all_zero_suppression_number
as either zero_suppression number
(if a radix and all_zero_suppression_aft
are present), or as zero_suppression otherwise.
An instance of all_sign_number
maps to:
a string of all spaces if the displayed magnitude
of Item is zero and the instance of all_sign_number
does not have a radix at its last character
position;
otherwise, the same result as if each sign_char
in all_sign_number_aft were '9', interpreting
the instance of all_sign_number as either
floating_LHS_sign number
(if a radix and all_sign_number_aft
are present), or as floating_LHS_sign otherwise.
An instance of all_currency_number
maps to:
a string of all spaces if the displayed magnitude
of Item is zero and the instance of all_currency_number
does not have a radix at its last character
position;
otherwise, the same result as if each currency_char
in all_currency_number_aft were '9', interpreting
the instance of all_currency_number as floating_$_currency
number or floating_#_currency
number (if a radix
and all_currency_number_aft are present),
or as floating_$_currency or floating_#_currency
otherwise.
Examples
In the result string values shown below, 'b' represents
the space character.
Item: Picture and Result Strings:
123456.78 Picture: "-###**_***_**9.99"
"bbb$***123,456.78"
"bbFF***123.456,78" (currency = "FF",
separator = '.',
radix mark = ',')
{
8652/0089}
{
AI95-00070}
123456.78 Picture: "-$**_***_**9.99"
Result: "b$***123,456.78"
"bFF***123.456,78" (currency = "FF",
separator = '.',
radix mark = ',')
0.0 Picture: "-$$$$$$.$$"
Result: "bbbbbbbbbb"
0.20 Picture: "-$$$$$$.$$"
Result: "bbbbbb$.20"
-1234.565 Picture: "<<<<_<<<.<<###>"
Result: "bb(1,234.57DMb)" (currency = "DM")
12345.67 Picture: "###_###_##9.99"
Result: "bbCHF12,345.67" (currency = "CHF")
Wording Changes from Ada 95
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