Strand Assignment: Difference between revisions

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     <table border="0" cellpadding="5" cellspacing="0" summary="">
     <table border="0" cellpadding="5" cellspacing="0" summary="">
     <tr>
     <tr>
       <td><apll> (A<sub>1</sub> A<sub>2</sub> ... A<sub>n</sub>)←R</apll></td>
       <td><apll>(A<sub>1</sub> A<sub>2</sub> ... A<sub>n</sub>)←R</apll></td>
       <td></td>
       <td></td>
       <td></td>
       <td></td>
       <td>Assigns the successive items of <apll>R</apll> to the names. </td>
       <td>Assigns the successive items of <apll>R</apll> to the names.</td>
     </tr>
     </tr>
     </table>
     </table>

Latest revision as of 22:54, 11 April 2008

(A1 A2 ... An)←R Assigns the successive items of R to the names.
A1 A2 ... An are assignable names, R is a scalar or vector.
If 1<⍴⍴R, signal a RANK ERROR.
If R is a scalar or one element vector, its item is assigned to each name, as in Ai←⊃⍬⍴R.
Otherwise, assume there are n names in the list:
If n≠⍴R, signal a LENGTH ERROR.
Otherwise, each successive item of R is assigned to each successive name, as in Ai←i⊃R.


For example, (A B C)←⊂⍳3 is shorthand for A←B←C←⍳3. In contrast, (A B C)←⍳3 is shorthand for A←1 ⋄ B←2 ⋄ C←3.

Note that (A B)←B A is a simple and efficient way to swap the values of the two names.