Ada grammar rules for names too permissive?

[olivermkellogg@gmail.com]

Hi,

RM section 3.2.2 defines

  subtype_mark ::= (subtype_)name

where (subtype_) is subtype_ rendered in italics, i.e. essentially

  subtype_mark ::= name

This looks overly permissive to me, considering 4.1

  name ::=
     direct_name | explicit_dereference
   | indexed_component | slice
   | selected_component | attribute_reference
   | type_conversion | function_call
   | character_literal | qualified_expression
   | generalized_reference | generalized_indexing
   | target_name

The AARM elaborates in paragraph 4a:

*Ramification*: Note that name includes attribute_reference; thus, S'Base can be used as a subtype_mark.

My question is, why is subtype_mark not defined as follows:

  compound_name ::= identifier { . identifier }

  subtype_mark ::= compound_name [ ' Base ]


Similarly, RM section 10.1.1 defines

  parent_unit_name ::= name

Here my question also applies, why not

  parent_unit_name ::= compound_name


- Oliver
(currently fighting ambiguities in the ANTLR grammar caused by laxity of rules)