Difference between revisions of "Yhc/API/Core"
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{{Yhc}} |
{{Yhc}} |
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| − | Yhc Core is a way of dumping and using the internal representation of Yhc in an external project |
+ | Yhc Core is a way of dumping and using the internal representation of Yhc in an external project. |
== Haddock Documentation == |
== Haddock Documentation == |
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* http://www.cs.york.ac.uk/fp/yhc/snapshot/docs/Yhc-Core.html |
* http://www.cs.york.ac.uk/fp/yhc/snapshot/docs/Yhc-Core.html |
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| − | == |
+ | == Overview == |
| + | Yhc.Core is a simple core Haskell-like language, feature case statements, let statements, top level lambda's and data values. Much of the syntactic sugar present in Haskell has gone (list comprehensions, typeclasses, overloaded names, nested lambdas) |
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| − | The following sequence of blog posts probably gives a useful introduction to Yhc Core. |
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| + | The strengths of Yhc.Core are: |
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| − | * http://yhc06.blogspot.com/2005/12/yhc-core.html |
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| + | |||
| − | * http://yhc06.blogspot.com/2006/07/yhc-core-v2.html |
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| + | * Simple representation of Haskell |
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| − | * http://yhc06.blogspot.com/2006/09/yhccore-api-available.html |
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| + | * Relatively simple to relate Core to original Haskell |
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| + | * Source locations are preseved |
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| + | * Minimal name mangling |
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| + | * Few synactic forms |
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| + | |||
| + | The weaknesses are: |
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| + | |||
| + | * Yhc cannot compile Yhc Core files, format is write only (fix is being worked on) |
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| + | * Types are not present (hard to fix, a lot of work) |
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| + | |||
| + | The intended users: |
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| + | |||
| + | * Analysis tools |
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| + | * Compiler backends |
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== Generating Core == |
== Generating Core == |
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| + | Yhc Core files are stored as .ycr files in a binary format. They can be generated by passing the -corep flag to the compiler, <tt>yhc -corep Main.hs</tt>. If Core files are required for the standard libraries these can be build using <tt>scons core=1</tt>. To view the Core output, <tt>yhc -core Main.hs</tt>, with the output going to the screen in a pretty printed format. |
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| − | To generate Core, simply give the compiler the option <tt>-core</tt> or <tt>-corep</tt>. For example, when compiling |
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| + | |||
| ⚫ | |||
| + | |||
| + | For an example of the Core output, taking the following program: |
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| + | |||
| + | <haskell> |
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| ⚫ | |||
| + | |||
| ⚫ | |||
| ⚫ | |||
| + | |||
| + | test x = map2 head2 x |
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| + | </haskell> |
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| + | Generates: |
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| − | module FibMain where |
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| + | <haskell> |
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| − | main xs = pam daeh xs |
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| + | Sample.head2 v220 = |
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| ⚫ | |||
| ⚫ | |||
| ⚫ | |||
| + | Sample._LAMBDA228 = |
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| ⚫ | |||
| ⚫ | |||
| + | Sample.map2 v223 v224 = |
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| ⚫ | |||
| ⚫ | |||
| ⚫ | |||
| ⚫ | |||
| + | (:) v225 v226 -> (:) (v223 v225) (Sample.pam v223 v226) |
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| + | Sample.test v227 = Sample.map2 Sample.head2 v227 |
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| ⚫ | |||
| + | </haskell> |
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| − | $ yhc -core FibMain.hs |
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| − | ====== Human Readable Core: |
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| − | FibMain.pam v220 v221 = |
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| ⚫ | |||
| ⚫ | |||
| ⚫ | |||
| − | (Prelude.: (YHC.Internal._apply1 v220 v222) (FibMain.pam v220 v223)) |
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| + | == Some little samples == |
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| − | FibMain.daeh v224 = |
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| ⚫ | |||
| − | Prelude.: v225 v226 -> v225 |
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| ⚫ | |||
| + | === Hello World, for Core === |
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| − | LAMBDA228 = |
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| ⚫ | |||
| + | The following snipet loads a Core file and prints it out. |
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| − | FibMain.main v227 = (FibMain.pam FibMain.daeh v227) |
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| + | <haskell> |
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| − | The <tt>-core</tt> option gives human readable Core output, in a style very similar to Haskell. The <tt>-corep</tt> option gives a <tt>deriving Show</tt> output of the Core, which can be read back in with <tt>read</tt> very easily. The machine Core also contains source code locations for statements. |
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| + | import Yhc.Core |
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| + | showFile x :: FilePath -> String |
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| + | showFile x = liftM show (loadCore x) |
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| + | </haskell> |
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| − | == |
+ | == See Also == |
| + | * [http://www.haskell.org/ghc/docs/latest/html/users_guide/ext-core.html GHC Core] |
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| − | * '''Types''' - Yhc has none, GHC has lots. |
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| − | * '''Familiarity''' - Yhc looks like Haskell, GHC is somewhat related, but not as close. |
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| − | * '''Name mangling''' - Yhc preserves names much better. |
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| − | * '''Source locations''' - Yhc keeps these, GHC doesn't. |
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== Users == |
== Users == |
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Revision as of 21:36, 15 October 2006
| Part of Yhc |
Yhc Core is a way of dumping and using the internal representation of Yhc in an external project.
Haddock Documentation
Overview
Yhc.Core is a simple core Haskell-like language, feature case statements, let statements, top level lambda's and data values. Much of the syntactic sugar present in Haskell has gone (list comprehensions, typeclasses, overloaded names, nested lambdas)
The strengths of Yhc.Core are:
- Simple representation of Haskell
- Relatively simple to relate Core to original Haskell
- Source locations are preseved
- Minimal name mangling
- Few synactic forms
The weaknesses are:
- Yhc cannot compile Yhc Core files, format is write only (fix is being worked on)
- Types are not present (hard to fix, a lot of work)
The intended users:
- Analysis tools
- Compiler backends
Generating Core
Yhc Core files are stored as .ycr files in a binary format. They can be generated by passing the -corep flag to the compiler, yhc -corep Main.hs. If Core files are required for the standard libraries these can be build using scons core=1. To view the Core output, yhc -core Main.hs, with the output going to the screen in a pretty printed format.
The Core output
For an example of the Core output, taking the following program:
head2 (x:xs) = x
map2 f [] = []
map2 f (x:xs) = f x : map f xs
test x = map2 head2 x
Generates:
Sample.head2 v220 =
case v220 of
(:) v221 v222 -> v221
_ -> Prelude.error Sample._LAMBDA228
Sample._LAMBDA228 =
"Sample: Pattern match failure in function at 9:1-9:15."
Sample.map2 v223 v224 =
case v224 of
[] -> []
(:) v225 v226 -> (:) (v223 v225) (Sample.pam v223 v226)
Sample.test v227 = Sample.map2 Sample.head2 v227
Some little samples
Hello World, for Core
The following snipet loads a Core file and prints it out.
import Yhc.Core
showFile x :: FilePath -> String
showFile x = liftM show (loadCore x)
See Also
Users
- Catch - Case and Termination Checker for Haskell by Neil Mitchell. This takes Core as an input.
- Dr Haskell - give hints to beginners about useful Haskell functions/idioms.