read for StdGen fails for arbitrary string
According to the docs for StdGen:
"In addition, read may be used to map an arbitrary string (not necessarily one produced by show) onto a value of type StdGen. In general, the read instance of StdGen has the following properties:
- It guarantees to succeed on any string.
- It guarantees to consume only a finite portion of the string.
- Different argument strings are likely to result in different results."
Here's what happens on my system:
C:\odm\ghc\lib>ghci GHCi, version 6.8.3: http://www.haskell.org/ghc/ :? for help Loading package base ... linking ... done. Prelude> :mod +System.Random Prelude System.Random> (read "tasty tofu") :: StdGen Loading package old-locale-1.0.0.0 ... linking ... done. Loading package old-time-1.0.0.0 ... linking ... done. Loading package random-1.0.0.0 ... linking ... done.
- ** Exception: Prelude.read: no parse
Prelude System.Random>
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Trac metadata
| Trac field | Value |
|---|---|
| Version | 6.8.3 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | libraries/random |
| Test case | |
| Differential revisions | |
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| Related | |
| Blocking | |
| CC | |
| Operating system | |
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