This library provides a type used to represent a number in
scientific notation. This is most frequently useful when
tokenizing or parsing a language. Languages like JSON and SQL
support numberic literals written in scientific notation, even
though backends frequently reject numbers outside a given range.
This library provides a compact representation of numbers in
scientific notation. In the common case of the coefficient and
then exponent each being small enough to be represented by a
machine word, this library avoids the need for any indirections
to retrieve the number. Consider some tokenization scheme:
`data Token = ... | Number {-# UNPACK #-} !Scientific`.
In this case, the unboxed coefficient and exponent are unpacked
into the Number data constructor if they can each be represented
by a machine word.
The internal representation does not normalize numbers. That is,
parsing `300e-2` resulting in a representation that uses `300` and
`-2` rather than `3` and `0`.
This work is deferred with the expectation that a number in scientific
notation is consumed either zero or one times. This library is not
optimized for use-cases that consume a Scientific more than once
since normalization is reapplied every time.
The primary library that operates in this same space is scientific.
Compared to scientific, this library distinguishes itself from
scientific in the following ways:
Correctness: scientific does not correctly handle large exponents. See
issue #62.
Parsing: The `scientific-notation` parser outperforms the scientific
parser that ships with aeson by a factor of five on small numbers.
Changes
Revision history for scientific-notation
0.1.7.0 – 2024-02-12
Add toInteger.
0.1.6.1 – 2024-02-06
Update package metadata.
0.1.6.0 – 2023-06-27
Support GHC 9.4 and 9.6. Drop support for GHCs older than 9.4.
Add fromInt and fromInt(8|16|32|64).
0.1.5.0 – 2022-07-15
Support GHC 9.2.
0.1.4.0 – 2022-03-16
Add fromWord8, fromWord16, and fromWord32.
Add roundShiftedToInt64.
Add encode.
Change builderUtf8 to present numbers in decimal notation without exponent
in many common cases. This is not considered a breaking change.