Ambient-Oriented Programming

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at:tutorial:basic [2020/02/09 19:32] – elisagat:tutorial:basic [2020/02/09 22:05] (current) – elisag
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-==== Multidimensional tables ====+ 
 + 
 + 
 + 
 + 
 + 
 + 
 + 
 +==== Multidimensional Tables ====
  
 As mentioned before, there is no special constructor for definition of multidimensional tables, a table entry can contain another table. In what follows we have a closer look to manipulations with multidimensional tables.  Consider a multidimensional table which is extensionally defined as follows: As mentioned before, there is no special constructor for definition of multidimensional tables, a table entry can contain another table. In what follows we have a closer look to manipulations with multidimensional tables.  Consider a multidimensional table which is extensionally defined as follows:
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 >a[1] >a[1]
 >>[1, 0, 0] >>[1, 0, 0]
 +>(a[1])[2] := 3;
 +>>3
 +>a
 +>>[[1, 3, 0], [0, 1, 0], [0, 0, 1]]
 </code> </code>
  
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 def b[3] { i := i + 1; aux := [0,0,0]; aux[i] :=1; aux}; def b[3] { i := i + 1; aux := [0,0,0]; aux[i] :=1; aux};
 >>[[1, 0, 0], [0, 1, 0], [0, 0, 1]] >>[[1, 0, 0], [0, 1, 0], [0, 0, 1]]
->b[1][2] 
->>0 
->(b[1])[2] := 3; 
->>3 
->b 
->>[[1, 3, 0], [0, 1, 0], [0, 0, 1]] 
 </code> </code>
 +
 +You can find later in this chapter a helper function for creating matrices  [[:at:tutorial:basic#optional_parameters|here]].
 +
 + 
  
 ===== Functions ===== ===== Functions =====
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 >> 21 >> 21
 </code> </code>
 +
 +
 +
 +
 +
  
 ==== Optional Parameters ==== ==== Optional Parameters ====
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 </code> </code>
  
-As is customary in languages with the above parameter passing semantics, AmbientTalk requires mandatory parameters to be defined //before// optional parameters, which should in turn be defined //before// a variable-argument parameter, if any.+As is customary in languages with the above optional arguments, AmbientTalk requires mandatory parameters to be defined //before// optional parameters, which should in turn be defined //before// a variable-argument parameter, if any. 
 + 
 +Let us show how to use optional arguments to define an auxilary function that creates matrices: 
 + 
 +<code> 
 +def makeMatrix(n, m := n, init := { |i,j| 0}){ 
 +  def [i,j] := [0,0]; 
 +  def makeCol(i,j) { 
 +     def col[m] { j := j + 1; init(i,j) } 
 +  }; 
 +  def matrix[n] { i := i + 1; makeCol(i,j)} 
 +}; 
 +>def c := makeMatrix(3); 
 +>>[[0, 0, 0], [0, 0, 0], [0, 0, 0]] 
 +>c[1] := [1,2,3] 
 +>>[1, 2, 3] 
 +>c 
 +>>[[1, 2, 3], [0, 0, 0], [0, 0, 0]] 
 +>def d := makeMatrix(4,4,  
 +  {|i,j| if: (i == j) then: {1} else: {0}}); 
 +>> [[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]] 
 +</code>
  
 ===== Closures ===== ===== Closures =====
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