Comments (2)
What should the result of formatDouble (standard places) be when it is the same distance to round up or down?
Rounding to even is the usual expected behavior when it really is the same distance to round up or down. But my point is that:
- There is no value of type
Double
which exactly represents12.345
. 12.345 :: Double
therefore means the closest representableDouble
to the real number12.345
, which happens to be0x1.8b0a3d70a3d71p3
and represents the rational number6949617174986097 % 562949953421312
.- This rational number is greater than
12.345
, by approximately6.4e-16
, and is thus slightly closer to12.35
than it is to12.34
.
Both base
and bytestring
have the same bug, and first round 0x1.8b0a3d70a3d71p3
to the minimum number of decimal digits needed to disambiguate it from its neighboring Double
s and only then round that intermediate result to two decimal digits, when the user has asked 0x1.8b0a3d70a3d71p3
to be rounded directly to two decimal digits.
from bytestring.
Seems like the choice is to have compatibility with base or be more correct.
from bytestring.
Related Issues (20)
- Compatibility with GHC's JavaScript backend HOT 1
- Overhaul Data.ByteString.Builder.RealFloat HOT 5
- Float and Double standard with precision 0 outputs incorrectly HOT 2
- Positive and Negative Zero Print Incorrect Precision
- Guidelines for using with WriterT HOT 2
- RealFloat Zero Padded Exponent HOT 7
- Faster Printing for Known Normal and Subnormal IEEE754 Floating Point Values
- Broken links in haddocks of `ShortByteString` HOT 1
- Audit `foreign import ccall` types
- Drop support for GHCs older than 8.4 HOT 1
- Add a splice of ShortByteString builder
- 0.12.1.0 fails to build on darwin aarch64 with GHC-8.10.7 HOT 13
- Create strict bytestrings from FixedPrim with zero copy HOT 6
- Lazy `zip` is stricter than expected
- unsafeUseAsCString(Len) may return a NULL pointer. HOT 9
- Document that `Data.ByteString.Lazy.appendFile` is not threadsafe.
- Eq and Ord for Builder
- Offer conversion with `Natural`. HOT 1
- Store a `State# RealWorld` in the ByteString HOT 2
Recommend Projects
-
React
A declarative, efficient, and flexible JavaScript library for building user interfaces.
-
Vue.js
🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
-
Typescript
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
-
TensorFlow
An Open Source Machine Learning Framework for Everyone
-
Django
The Web framework for perfectionists with deadlines.
-
Laravel
A PHP framework for web artisans
-
D3
Bring data to life with SVG, Canvas and HTML. 📊📈🎉
-
Recommend Topics
-
javascript
JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
-
web
Some thing interesting about web. New door for the world.
-
server
A server is a program made to process requests and deliver data to clients.
-
Machine learning
Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
-
Visualization
Some thing interesting about visualization, use data art
-
Game
Some thing interesting about game, make everyone happy.
Recommend Org
-
Facebook
We are working to build community through open source technology. NB: members must have two-factor auth.
-
Microsoft
Open source projects and samples from Microsoft.
-
Google
Google ❤️ Open Source for everyone.
-
Alibaba
Alibaba Open Source for everyone
-
D3
Data-Driven Documents codes.
-
Tencent
China tencent open source team.
from bytestring.