Cookbook/Compilers and interpreters: Difference between revisions

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
checking a type	:t	Prelude> :t "Hello" "Hello" :: [Char] Prelude> :t length length :: [a] -> Int
loading a file	:l	Prelude> :l Foo.hs [1 of 1] Compiling Foo ( Foo.hs, interpreted ) Ok, modules loaded: Foo.
reloading all loaded files	:r	Prelude> :r

Debugging

Problem	Solution	Examples
setting a break point	:break	Prelude> :break 2 -- sets a break point in line 2

Hugs

TODO

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