Difference between revisions of "Cookbook/Compilers and interpreters"
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| − | = |
+ | == GHC == |
| + | {| class="wikitable" |
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| − | A lot of functions are defined in the [http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html Prelude]. Also, if you ever want to search for a function, based on the name, type or module, take a look at the excellent [http://www.haskell.org/hoogle/ Hoogle]. This is for a lot of people a must-have while debugging and writing Haskell programs. |
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| + | |- |
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| + | ! Problem |
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| + | ! Solution |
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| + | ! Examples |
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| + | |- |
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| + | | compiling and linking an executable |
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| + | | --make |
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| + | |<pre>ghc --make Main.hs --> Main</pre> |
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| + | |- |
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| + | | compiling without linking |
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| + | | -c |
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| + | |<pre>ghc -c Foo.hs --> Foo.hi, Foo.o</pre> |
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| + | |- |
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| + | | generating Assembler code |
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| + | | -S |
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| + | |<pre>ghc -S Foo.hs --> Foo.hi, Foo.s</pre> |
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| + | |- |
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| + | | generating C code |
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| + | | -C |
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| + | |<pre>ghc -C Foo.hs --> Foo.hc, Foo.hi</pre> |
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| + | |- |
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| + | | linking files into an executable |
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| + | | -o |
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| + | |<pre>ghc -o test Foo.o Bar.o Baz.p --> test</pre> |
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| + | |} |
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| − | = GHCi |
+ | == GHCi == |
| − | == GHCi interaction == |
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| − | To start GHCi from a command prompt, simply type `ghci' |
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| + | === General === |
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| − | $ ghci |
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| − | ___ ___ _ |
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| − | / _ \ /\ /\/ __(_) |
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| − | / /_\// /_/ / / | | GHC Interactive, version 6.6, for Haskell 98. |
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| − | / /_\\/ __ / /___| | http://www.haskell.org/ghc/ |
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| − | \____/\/ /_/\____/|_| Type :? for help. |
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| − | |||
| − | Loading package base ... linking ... done. |
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| − | Prelude> |
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| + | {| class="wikitable" |
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| − | [http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html Prelude] is the "base" library of Haskell. |
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| + | |- |
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| − | |||
| + | ! Problem |
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| − | To create variables at the GHCi prompt, use `let' |
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| + | ! Solution |
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| − | <haskell> |
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| + | ! Examples |
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| − | Prelude> let x = 5 |
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| + | |- |
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| − | Prelude> x |
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| + | | checking a definition |
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| − | 5 |
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| + | | :i |
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| − | Prelude> let y = 3 |
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| + | |<haskell> |
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| − | Prelude> y |
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| + | Prelude> :i True |
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| − | 3 |
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| + | data Bool = ... | True -- Defined in GHC.Bool |
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| − | Prelude> x + y |
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| − | 8 |
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</haskell> |
</haskell> |
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| + | |- |
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| + | | checking a type |
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| + | | :t |
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| + | |<haskell> |
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| + | Prelude> :t "Hello" |
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| + | "Hello" :: [Char] |
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| + | Prelude> :t length |
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| − | `let' is also the way to create simple functions at the GHCi prompt |
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| + | length :: [a] -> Int |
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| − | <haskell> |
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| − | Prelude> let fact n = product [1..n] |
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| − | Prelude> fact 5 |
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| − | 120 |
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</haskell> |
</haskell> |
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| + | |- |
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| + | | loading a file |
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| + | | :l |
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| + | |<haskell> |
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| + | Prelude> :l Foo.hs |
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| + | [1 of 1] Compiling Foo ( Foo.hs, interpreted ) |
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| + | Ok, modules loaded: Foo. |
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| + | </haskell> |
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| + | |- |
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| + | | reloading all loaded files |
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| + | | :r |
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| + | |<haskell> |
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| + | Prelude> :r |
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| + | </haskell> |
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| + | |} |
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| + | === Debugging === |
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| + | {| class="wikitable" |
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| − | == Checking Types == |
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| + | |- |
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| − | To check the type of an expression or function, use the command `:t' |
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| + | ! Problem |
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| − | <haskell> |
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| + | ! Solution |
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| − | Prelude> :t x |
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| + | ! Examples |
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| − | x :: Integer |
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| + | |- |
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| − | Prelude> :t "Hello" |
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| + | | setting a break point |
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| − | "Hello" :: [Char] |
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| + | | :break |
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| − | </haskell> |
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| + | |<haskell> |
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| − | Haskell has the following types defined in the [http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html Standard Prelude]. |
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| + | Prelude> :break 2 -- sets a break point in line 2 |
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| − | <haskell> |
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| − | Int -- bounded, word-sized integers |
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| − | Integer -- unbounded integers |
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| − | Double -- floating point values |
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| − | Char -- characters |
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| − | String -- equivalent to [Char], strings are lists of characters |
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| − | () -- the unit type |
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| − | Bool -- booleans |
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| − | [a] -- lists |
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| − | (a,b) -- tuples / product types |
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| − | Either a b -- sum types |
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| − | Maybe a -- optional values |
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</haskell> |
</haskell> |
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| + | |} |
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| + | |||
| + | == Hugs == |
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| + | |||
| + | TODO |
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Latest revision as of 08:33, 25 January 2010
GHC
| Problem | Solution | Examples |
|---|---|---|
| compiling and linking an executable | --make | ghc --make Main.hs --> Main |
| compiling without linking | -c | ghc -c Foo.hs --> Foo.hi, Foo.o |
| generating Assembler code | -S | ghc -S Foo.hs --> Foo.hi, Foo.s |
| generating C code | -C | ghc -C Foo.hs --> Foo.hc, Foo.hi |
| linking files into an executable | -o | ghc -o test Foo.o Bar.o Baz.p --> test |
GHCi
General
| Problem | Solution | Examples |
|---|---|---|
| checking a definition | :i | Prelude> :i True
data Bool = ... | True -- Defined in GHC.Bool
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| checking a type | :t | Prelude> :t "Hello"
"Hello" :: [Char]
Prelude> :t length
length :: [a] -> Int
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| loading a file | :l | Prelude> :l Foo.hs
[1 of 1] Compiling Foo ( Foo.hs, interpreted )
Ok, modules loaded: Foo.
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| reloading all loaded files | :r | Prelude> :r
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Debugging
| Problem | Solution | Examples |
|---|---|---|
| setting a break point | :break | Prelude> :break 2 -- sets a break point in line 2
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Hugs
TODO