Ada 95 Reference Manual
2.4.1 Decimal Literals
A decimal_literal is a numeric_literal in the conventional decimal notation (that is, the base is ten).
Syntax
decimal_literal ::= numeral [.numeral] [exponent]
numeral ::= digit {[underline] digit}
exponent ::= E [+] numeral | E - numeral
An exponent for an integer literal shall not have a minus sign.
Static Semantics
An underline character in a numeric_literal does not affect its meaning. The letter E of an exponent can be written either in lower case or in upper case, with the same meaning.
An exponent indicates the power of ten by which the value of the decimal_literal without the exponent is to be multiplied to obtain the value of the decimal_literal with the exponent.
Examples
Examples of decimal literals:
12 0 1E6 123_456 -- integer literals
12.0 0.0 0.456 3.14159_26 -- real literals
12.0 0.0 0.456 3.14159_26 -- real literals
