Re: [fpc-pascal] More syntax questions (part 2)
Michael Van Canneyt via fpc-pascal wrote: 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 ? 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. Of course, a rule like proc-identifier = procedure-identifier | function-identifier . makes no sense without the semantics of a symbol table (to decide between the two), but rules like procedure-heading = "PROCEDURE" procedure-identifier function-heading = "FUNCTION" function-identifier procedure-identifier = identifier . function-identifier = identifier . do make sense, even without semantics, because in the parsing(-only) tree, a procedure-identifier (etc.) node is now marked as such, and not just as identifier. In certain applications of a parsing(-only) tree this is quite useful. Regards, Adriaan van Os ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] More syntax questions (part 2)
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 ?
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 = identifier-list ":" [ "ARRAY" "OF" ] parameter-type
| identifier ":" type-identifier "=" default-parameter-value .
I couldn't find a rule for . If equals
then it may be easier to name it ?
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 .
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 . 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 ?
guid = single-quoted-string .
string-constant-declaration = single-quoted-string .
string-literal = single-quoted-string .
stringconstant = single-quoted-string .
Yes.
where 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 for which I can't find
the rule. What is it ?
identifier.
23. Section 12.2 defines a rule that references rules
and .
function-call = ( function-identifier | method-designator |
qualified-method-designator | variable-reference ) [ actual-parameter-list ]
.
I can't find the rules for and
. 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
.
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 . What is it ?
default-parameter-value = constant-expression
25. Section 16.2 defines a rule that refers to a rule
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 . 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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fpc-pascal
[fpc-pascal] More syntax questions (part 2)
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 ?
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 .
18. Section 14.4.1 defines a rule
value-parameter = identifier-list ":" [ "ARRAY" "OF" ] parameter-type | identifier ":"
type-identifier "=" default-parameter-value .
I couldn't find a rule for . If equals then it
may be easier to name it ?
19. Sections 3.6, 14.2 and 15.2 refer to a rule .
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 . Can I assume ?
result-type = type-identifier .
20. For the following rules, I couldn't find a definition in the Language Reference. Can I assume
they can all be defined as ?
guid = single-quoted-string .
string-constant-declaration = single-quoted-string .
string-literal = single-quoted-string .
stringconstant = single-quoted-string .
where 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 ?
21. Can I assume ?
statement-list = statement { ";" statement } .
statementlist = statement-list .
22. Various rules refer to a rule for which I can't find
the rule. What is it ?
23. Section 12.2 defines a rule that references rules
and .
function-call = ( function-identifier | method-designator | qualified-method-designator |
variable-reference ) [ actual-parameter-list ] .
I can't find the rules for and
. What are they ?
24. Sections 14.4.1 and 14.4.4 define rules that refer to a rule
.
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 . What is it ?
25. Section 16.2 defines a rule that refers to a rule
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 . What is it ?
(more to follow)
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