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--- codesnippets:bindingandpatternmatching [2021/04/14 11:06] – [Tuples] f2b216
+++ codesnippets:bindingandpatternmatching [2025/10/08 00:48] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
-====== Binding ======
+====== Binding and pattern matching ======
-~~DISCUSSION~~
 A binding binds a name or even several names with a function definition.
@@ Line 133: / Line 132: @@
     * but with binding names
   * example
-  *
     * code lines:<code Haskell>
 data MyData = MyVariantA Integer Char Double | MyVariantB Int | MyVariantC
@@ Line 145: / Line 143: @@
         print b
         print zet
-        print n
 data MyData = MyVariantA Integer Char Double | MyVariantB Int | MyVariantC
-    deriving Show
 MyVariantA first b zet = MyVariantA 12 'a' 23.4
@@ Line 154: / Line 150: @@
 MyVariantB n = MyVariantB 123
-MyVariantC = MyVariantC
+MyVariantC = MyVariantC -- is not binding anything, but compiles consistently
 </code>
     * with compiler warning, which we ignore for pedagogical reasons
@@ Line 163: / Line 159: @@
 </code>
+  * NOTE: I may look like: It does'nt make sense to have a constructor no elements. However, ''MyVariantC'' is already a value in itself, and can be used to differentiate between the variants.
-==== Example 2 ====
-<code Haskell>
-Person name number = Person "Lutz" 1243
-</code>
-...works in...
-<code Haskell>
-module Main where
-main :: IO ()
-main =
-        do
-                print name
-                print number
-data Person = Person { sName :: String, iNumber :: Integer }
-Person name number = Person "Lutz" 1243
-</code>
+===== ✎ =====
+~~DISCUSSION~~