tasks a-s

Task/Pattern-matching/Rascal/pattern-matching-1.rascal

@@ -0,0 +1,65 @@
+// Literal
+rascal>123 := 123
+bool: true
+
+// VariableDeclaration
+rascal>if(str S := "abc")
+>>>>>>>   println("Match succeeds, S == \"<S>\"");
+Match succeeds, S == "abc"
+ok
+
+// MultiVariable
+rascal>if([10, N*, 50] := [10, 20, 30, 40, 50])
+>>>>>>>   println("Match succeeds, N == <N>");
+Match succeeds, N == [20,30,40]
+ok
+
+// Variable
+rascal>N = 10;
+int: 10
+rascal>N := 10;
+bool: true
+rascal>N := 20;
+bool: false
+
+// Set and List
+rascal>if({10, set[int] S, 50} := {50, 40, 30, 20, 10})
+>>>>>>>   println("Match succeeded, S = <S>");
+Match succeeded, S = {30,40,20}
+ok
+
+rascal>for([L1*, L2*] := [10, 20, 30, 40, 50])
+>>>>>>>    println("<L1> and <L2>");
+[] and [10,20,30,40,50]
+[10] and [20,30,40,50]
+[10,20] and [30,40,50]
+[10,20,30] and [40,50]
+[10,20,30,40] and [50]
+[10,20,30,40,50] and []
+list[void]: []
+
+// Descendant
+rascal>T = red(red(black(leaf(1), leaf(2)), black(leaf(3), leaf(4))), black(leaf(5), leaf(4)));
+rascal>for(/black(_,leaf(4)) := T)
+>>>>>>>    println("Match!");
+Match!
+Match!
+list[void]: []
+
+rascal>for(/black(_,leaf(int N)) := T)
+>>>>>>>    println("Match <N>");
+Match 2
+Match 4
+Match 4
+list[void]: []
+
+rascal>for(/int N := T)
+>>>>>>>    append N;
+list[int]: [1,2,3,4,5,4]
+
+// Labelled
+rascal>for(/M:black(_,leaf(4)) := T)
+>>>>>>>    println("Match <M>");
+Match black(leaf(3),leaf(4))
+Match black(leaf(5),leaf(4))
+list[void]: []