On Sat, 16 Dec 2023, Adriaan van Os via fpc-pascal wrote:
More questions about the FreePascal Language Reference (version 3.2.0) part
2
17. For the following rules, I couldn't find a definition in the Language
Reference. Can I assume they can all be defined as <identifier> ?
object-type-identifier = identifier .
field-identifier = identifier .
interface-identifier = identifier .
interface-type-identifier = identifier .
method-identifier = identifier .
procedure-identifier = identifier .
protocol-identifier = identifier .
protocol-type-identifier = identifier .
qualified-method-identifier = identifier .
result-identifier = identifier .
type-identifier = identifier .
function-identifier = identifier .
unit-identifier = identifier .
variable-identifier = identifier .
Yes.
The idea was to use these "dedicated names" to convey that the identifier must
be of a certain type.
You cannot express this concept in a formal syntax, but for a formal syntax the
above is correct.
18. Section 14.4.1 defines a rule <value-parameter>
value-parameter = identifier-list ":" [ "ARRAY" "OF" ] parameter-type
| identifier ":" type-identifier "=" default-parameter-value .
I couldn't find a rule for <parameter-type>. If <parameter-type> equals
<type-identifier> then it may be easier to name it <type-identifier> ?
Not quite. it can also be 'const' (the 'array of const' construct).
This diagram needs to be enhanced, I suppose the following is more correct:
(identifier [ "=" constant-expression ] | "array" "of" ("const" | identifier))
19. Sections 3.6, 14.2 and 15.2 refer to a rule <result-type>.
function-header = "FUNCTION" formal-parameter-list ":" result-type .
function-header = "FUNCTION" ( identifier |
qualified-method-identifier ) formal-parameter-list ":" result-type [
modifiers ] [ hintdirectives ] .
operator-definition = "operator" ( assignment-operator-definition |
arithmetic-operator-definition | comparision-operator-definition )
result-identifier ":" result-type ";" subroutine-block .
I couldn't find a rule for <result-type>. Can I assume ?
result-type = type-identifier .
Yes.
20. For the following rules, I couldn't find a definition in the Language
Reference. Can I assume they can all be defined as <single-quoted-string> ?
guid = single-quoted-string .
string-constant-declaration = single-quoted-string .
string-literal = single-quoted-string .
stringconstant = single-quoted-string .
Yes.
where <single-quoted-string> is a parser built-in rule that parses two
consecutive single-quote chars as a literal single-quote char ? and that may
not contain CR and LF characters ? or any other control characters ?
Yes.
Following your remarks, I was planning to introduce a list of "parser built-in"
rules, as I need them to define the constants.
21. Can I assume ?
statement-list = statement { ";" statement } .
statementlist = statement-list .
Yes.
22. Various rules refer to a rule <variable-reference> for which I can't find
the rule. What is it ?
identifier.
23. Section 12.2 defines a rule <function-call> that references rules
<qualified-method-designator> and <method-designator>.
function-call = ( function-identifier | method-designator |
qualified-method-designator | variable-reference ) [ actual-parameter-list ]
.
I can't find the rules for <qualified-method-designator> and
<method-designator>. What are they ?
With the appearance of nested classes and type definitions, they are actually
the same.
method-designator = qualified-method-designator = identifier ({ "." identifier
})
So the function-call can be simplified to
function-call = ( method-designator | variable-reference ) [
actual-parameter-list ]
maybe introducing a
fully-qualified-identifier = identifier ({ "." identifier })
and using that everywhere instead is a better approach.
24. Sections 14.4.1 and 14.4.4 define rules that refer to a rule
<default-parameter-value>.
value-parameter = identifier-list ":" [ "ARRAY" "OF" ] parameter-type
| identifier ":" type-identifier "=" default-parameter-value .
constant-parameter = "CONST" ( identifier-list [ ":" [ "ARRAY" "OF" ]
type-identifier ] | identifier ":" type-identifier "="
default-parameter-value ) .
I can't find the rule for <default-parameter-value>. What is it ?
default-parameter-value = constant-expression
25. Section 16.2 defines a rule <interface-part> that refers to a rule
<property-declaration-part>
interface-part = "INTERFACE" [ uses-clause ] {
constant-declaration-part | type-declaration-part |
variable-declaration-part | property-declaration-part |
procedure-headers-part } .
I can't find the rule <property-declaration-part>. What is it ?
That should be
property-declaration-part = property definition { ";" property definition }
("property definition" is defined in the class declaration diagram)
Michael.
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