Initial data commit

Task/Loops-Nested/Smalltalk/loops-nested-5.st

@@ -0,0 +1,49 @@
+"this simple implementation of a bidimensional array
+ lacks controls over the indexes, but has a way of iterating
+ over array's elements, from left to right and top to bottom"
+Object subclass: BiArray [
+  |cols rows elements|
+  BiArray class >> columns: columns  rows: howManyRows [
+      ^ super basicNew init: columns per: howManyRows
+  ]
+  init: columns per: howManyRows [
+     cols := columns.
+     rows := howManyRows.
+     elements := Array new: ( columns * howManyRows )
+  ]
+  calcIndex: biIndex [ "column, row (x,y) to linear"
+    ^ ( (biIndex at: 1) + (((biIndex at: 2) - 1) * cols) )
+  ]
+  at: biIndex [ "biIndex is an indexable containing column row"
+     ^ elements at: (self calcIndex: biIndex).
+  ]
+  directAt: i [ ^ elements at: i ]
+  at: biIndex put: anObject [
+     elements at: (self calcIndex: biIndex) put: anObject
+  ]
+  whileTrue: aBlock do: anotherBlock [
+     |i lim|
+     i := 1. lim := rows * cols.
+     [ ( i <= lim )
+         & (aBlock value: (self directAt: i) )
+     ] whileTrue: [
+         anotherBlock value: (self directAt: i).
+         i := i + 1.
+       ]
+  ]
+].
+
+|biarr|
+biarr := BiArray columns: 10 rows: 10.
+
+"fill the array; this illustrates nested loop but not how to
+ escape from them"
+1 to: 10 do: [ :c |
+  1 to: 10 do: [ :r |
+     biarr at: {c . r} put: (Random between: 1 and: 20)
+  ]
+].
+
+"loop searching for 20; each block gets the element passed as argument"
+biarr whileTrue: [ :v | v ~= 20 ]
+      do: [ :v | v displayNl ]