2.4.5 Floating point literals
Keywords: ref

##
2.4.5 Floating point literals

Floating point literals are described by the following lexical definitions:

  `floatnumber` | ::= | `pointfloat | exponentfloat`
  `pointfloat` | ::= | `[intpart] fraction | intpart "."`
  `exponentfloat` | ::= | `(intpart | pointfloat) exponent`
  `intpart` | ::= | `digit+`
  `fraction` | ::= | `"." digit+`
  `exponent` | ::= | `("e" | "E") ["+" | "-"] digit+`

  Download entire grammar as text.

Note that the integer and exponent parts of floating point numbers can look like octal integers, but are interpreted using radix 10. For example, "`077e010`" is legal, and denotes the same number as "`77e10`". The allowed range of floating point literals is implementation-dependent. Some examples of floating point literals:

      3.14    10.    .001    1e100    3.14e-10    0e0

Note that numeric literals do not include a sign; a phrase like `-1` is actually an expression composed of the operator `-` and the literal `1`.