Decimal numbers

BNF notation
<decimal-literal> ::= <decimal-format1> | <decimal-format2> | <decimal-format3> | <decimal-format4>
<decimal-format1> ::= <decimal-digits> "." <decimal-digits> [<exp-part>]
<decimal-format2> ::= "." <decimal-digits> [<exp-part>]
<decimal-format3> ::= <decimal-digits> <exp-part>
<decimal-format4> ::= <decimal-digits>
<decimal-digits> ::= <decimal-digit> | <decimal-digits> <decimal-digit>
<decimal-digit> ::= "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"
<exp-part> ::= ( "E" | "e" ) [<sign>] <decimal-digits>
<sign> ::= "+" | "-"

Range:
-1.79769313486231e308 to 1.79769313486231e308
MIN to MAX ( predefined variables )

Examples:
1.2, 1.2e+3, 1.2E-3, .123, .123E-4, 12E+3, 12