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#### 23.2.14 *read-default-float-format* [Variable]

#### Value Type::

one of the atomic type specifiers short-float, single-float, double-float, or long-float, or else some other type specifier defined by the implementation to be acceptable.

#### Initial Value::

The symbol single-float.

#### Description::

Controls the floating-point format that is to be used when reading a floating-point number that has no exponent marker or that has `e` or `E` for an exponent marker. Other exponent markers explicitly prescribe the floating-point format to be used.

The printer uses *read-default-float-format* to guide the choice of exponent markers when printing floating-point numbers.

#### Examples::

     (let ((*read-default-float-format* 'double-float))
       (read-from-string "(1.0 1.0e0 1.0s0 1.0f0 1.0d0 1.0L0)"))
    ⇒  (1.0   1.0   1.0   1.0 1.0   1.0)   ;Implementation has float format F.
    ⇒  (1.0   1.0   1.0s0 1.0 1.0   1.0)   ;Implementation has float formats S and F.
    ⇒  (1.0d0 1.0d0 1.0   1.0 1.0d0 1.0d0) ;Implementation has float formats F and D.
    ⇒  (1.0d0 1.0d0 1.0s0 1.0 1.0d0 1.0d0) ;Implementation has float formats S, F, D.
    ⇒  (1.0d0 1.0d0 1.0   1.0 1.0d0 1.0L0) ;Implementation has float formats F, D, L.
    ⇒  (1.0d0 1.0d0 1.0s0 1.0 1.0d0 1.0L0) ;Implementation has formats S, F, D, L.