Abstract-syntax
Abstract syntax of ABNF.
ABNF is a language to describe the concrete syntax of languages.
Being itself a language,
ABNF has its own concrete syntax, described in [RFC:4] using ABNF itself.
To break the self-description circularity,
we start by formalizing an abstract syntax of ABNF,
based on an inspection of the concrete syntax in [RFC:4].
The ABNF abstract syntax abstracts away from the ABNF concrete syntax
things that are not relevant to the ABNF semantics,
such as blank space and comments,
as well as certain restrictions
that are not needed to define the semantics.
Subtopics
- Convenience-constructors
- Utilities to conveniently construct abstract syntactic entities.
- Num-val
- Fixtype of numeric value notations.
- Char-val
- Fixtype of character value notations.
- Repeat-range
- Fixtype of repetition ranges.
- Rulename
- Fixtype of rule names.
- Rule
- Fixtype of rules.
- Rulename-option
- Fixtype of rule names and nil.
- Num-base
- Fixtype of numeric bases.
- Rule-option
- Fixtype of rules and nil.
- Prose-val
- Fixtype of prose value notations.
- Rulelist
- Fixtype of lists of rules.
- Char-val-set
- Fixtype of sets of character value notations.
- Rulename-set
- Finite sets of rule names.
- Rulename-list
- Fixtype of lists of rule names.
- Grammar
- An ABNF grammar is a list of rules.
- Alt/conc/rep/elem
