Strand Assignment: Difference between revisions

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For example, <apl size="large">(A B C)←{enclose}{iota}3</apl> is shorthand for <apl size="large">A{is}B{is}C{is}{iota}3</apl>.  In contrast, <apl size="large">(A B C)←{iota}3</apl> is shorthand for <apl size="large">A←1 {diamond} B←2 {diamond} C←3</apl>.
For example, <apl size="large">(A B C)←⊂⍳3</apl> is shorthand for <apl size="large">A←B←C←⍳3</apl>.  In contrast, <apl size="large">(A B C)←⍳3</apl> is shorthand for <apl size="large">A←1 B←2 C←3</apl>.


Note that <apl size="large">(A B)←B A</apl> is a simple and efficient way to swap the values of the two names.
Note that <apl size="large">(A B)←B A</apl> is a simple and efficient way to swap the values of the two names.

Revision as of 15:53, 9 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.