Numbers

Numerical constants appearing in other sections of this definition are of the following types:

1. Constants for presetting, optionally signed.

2. Integers and reals as primaries in expressions. A sign attached to a primary belongs syntactically to the expression and not to the number.

3. Integers and signed integers used in declarations or specifications, typically for defining fixed scales, bit-fields and array bounds.

The syntactic classification is as follows:

        Constant ::= 
    Number
        Addoperator
        Number
      

        Number ::= 
    Real
        Integer
      

        Signedinteger ::= 
    Integer
        Addoperator
        Integer
      

        Real ::= 
    Digitlist . Digitlist
        Digitlist
        ₁₀
        Signedinteger
        ₁₀
        Signedinteger
        Digitlist . Digitlist
        ₁₀
        Signedinteger
        OCTAL ( Octallist . Octallist ) 
      

        Integer ::= 
    Digitlist
        OCTAL ( Octallist )
        LITERAL ( printing character )
      

The further expansions are

        Digitlist ::= 
    Digit
        Digit
        Digitlist
      

        Octallist ::= 
    Octaldigit
        Octaldigit
        Octalist
      

        Octaldigit ::= 0 1 2 3 4 5 6 7
      

where 0 to 7 are alternatives.