1 General
Discussion: This Annotated Ada Reference
Manual (AARM) contains the entire text of the fourth edition of the Ada
Reference Manual as updated for Ada 202y (referred
to here as the Ada 202y 2022
RM), plus certain annotations. The annotations give a more in-depth analysis
of the language. They describe the reason for each nonobvious rule, and
point out interesting ramifications of the rules and interactions among
the rules (interesting to language lawyers, that is). Differences between
Ada 83, Ada 95, Ada 2005, Ada 2012, Ada 2022, and
Ada 202y and Ada 2022 are listed.
(The text you are reading now is an annotation.)
The AARM stresses detailed correctness and uniformity
over readability and understandability. We're not trying to make the
language “appear” simple here; on the contrary, we're trying
to expose hidden complexities, so we can more easily detect language
bugs. The Ada 202y 2022
RM, on the other hand, is intended to be a more readable document for
programmers.
The annotations
in the AARM are as follows:
Text that is logically redundant is shown
[in square brackets, like this]. Technically, such text could be written
as a Note in the Ada 202y 2022
RM (and the Ada 95 and 2005 RMs before it), since it is really a theorem
that can be proven from the nonredundant rules of the language. We use
the square brackets instead when it seems to make the Ada 202y 2022
RM more readable.
The rules of the language (and some AARM-only
text) are categorized, and placed under certain
sub-headings that
indicate the category. For example, the distinction between Name Resolution
Rules and Legality Rules is particularly important, as explained in
8.6.
Text under the following sub-headings appears
in both documents:
The unlabeled text at the beginning
of each clause or subclause,
Syntax,
Name Resolution Rules,
Legality Rules,
Static Semantics,
Post-Compilation Rules,
Dynamic Semantics,
Bounded (Run-Time) Errors,
Erroneous Execution,
Implementation Requirements,
Documentation Requirements,
Metrics,
Implementation Permissions,
Implementation Advice,
Usage.
NOTES,
Examples.
Text under the following sub-headings does
not appear in the Ada 202y 2022
RM:
Language Design Principles,
Inconsistencies With Ada 83,
Incompatibilities With Ada
83,
Extensions to Ada 83,
Wording Changes from Ada 83,
Inconsistencies With Ada 95,
Incompatibilities With Ada
95,
Extensions to Ada 95,
Wording Changes from Ada 95,
Inconsistencies With Ada 2005,
Incompatibilities With Ada
2005,
Extensions to Ada 2005,
Wording Changes from Ada 2005,
Inconsistencies With Ada 2012,
Incompatibilities With Ada
2012,
Extensions to Ada 2012,
Wording Changes from Ada 2012.
Inconsistencies
With Ada 2022,
Incompatibilities
With Ada 2022,
Extensions
to Ada 2022,
Wording
Changes from Ada 2022.
The AARM also includes the following kinds
of annotations. These do not necessarily annotate the immediately preceding
rule, although they often do.
Reason: An explanation of why a certain
rule is necessary, or why it is worded in a certain way.
Ramification: An obscure ramification
of the rules that is of interest only to language lawyers. (If a ramification
of the rules is of interest to programmers, then it appears under NOTES.)
Proof: An informal proof explaining how
a given Note or [marked-as-redundant] piece of text follows from the
other rules of the language.
Implementation Note: A hint about how
to implement a feature, or a particular potential pitfall that an implementer
needs to be aware of.
Change: Change annotations are not used
in this version. Changes from previous versions have been removed. Changes
in this version are marked with versioned paragraph numbers, as explained
in the “Corrigendum Changes” clause of the “Introduction”.
Discussion: Other annotations not covered
by the above.
To be honest: A rule that is considered
logically necessary to the definition of the language, but which is so
obscure or pedantic that only a language lawyer would care. These are
the only annotations that could be considered part of the language definition.
Discussion: In general, the Ada 202y 2022
RM text appears in the normal font, whereas AARM-only text appears in
a smaller font. Notes also appear in the smaller font, as recommended
by ISO/IEC style guidelines. Ada examples are also usually printed in
a smaller font.
If you have trouble finding things, be sure
to use the index.
Each defined term appears there,
and also in
italics, like this. Syntactic categories defined in
BNF are also indexed.
A definition marked “[distributed]”
is the main definition for a term whose complete definition is given
in pieces distributed throughout the document. The pieces are marked
“[partial]” or with a phrase explaining what cases the partial
definition applies to.
Ada 2005 and 2012 Editions sponsored in part by Ada-Europe
