Execute Expression R←X(85⌶)Y

Executes an expression.

Y is a character vector containing an APL expression.

The function executes the expression in Y exactly as it would be executed by the monadic Execute primitive function ⍎, but handles shy results of the execution rather differently.

The left argument X determines how a shy result from the execution of Y is treated and is either 0 or 1.

If X is 1, and the expression in Y returns an explicit result, R is that result. If the expression in Y returns no result or returns a shy result, the function signals ERROR 85. Effectively, a shy result is discarded.

If X is 0, and the expression in Y returns an explicit result or a shy result, R is that result (but is no longer shy). If the expression in Y returns no result, the function signals ERROR 85.

Examples

      ⍎'a←42'
      ⎕← ⍎'a←42'     ⍝ shy result
42
      0 (85⌶) 'a←42' ⍝ not shy
42
      1 (85⌶) 'a←42'
ERROR 85
      1(85⌶)'a←42'
     ∧