State of Object R←⎕STATE Y

Y must be a simple character scalar or vector which is taken to be the name of an APL object or a system variable. The result returned is a nested vector of 4 elements as described below. ⎕STATE supplies information about shadowed or localised objects that is otherwise unobtainable.

1⊃R	Boolean vector, element set to 1 if and only if this level shadows Y . Note: (⍴1⊃R)=⍴⎕LC
2⊃R	Numeric vector giving the stack state of this name as it entered this level. Note: (⍴2⊃R)=⍴⎕LC 0=not on stack 1=suspended 2=pendent (may also be suspended)
3⊃R	Numeric vector giving the name classification of Y as it entered this level. Note: (⍴3⊃R)=+/1⊃R
4⊃R	Vector giving the contents of Y before it was shadowed at this level. Note: (⍴4⊃R)=+/0≠3⊃R

Example

      ⎕FMT∘⎕OR¨'FN1' 'FN2' 'FN3'
    ∇ FN1;A;B;C      ∇ FN2;A;C               ∇ FN3;A
[1]   A←1        [1]   A←'HELLO'         [1]   A←100
[2]   B←2        [2]   B←'EVERYONE'      [2]   ∘
[3]   C←3        [3]   C←'HOW ARE YOU?'      ∇
[4]   FN2        [4]  FN3
    ∇                ∇

      )SI
#.FN3[2]*
#.FN2[4]
#.FN1[4]

      ⎕STATE 'A'
 1 1 1  0 0 0  2 2 0   HELLO  1

       ⎕FMT∘⎕OR¨'foo' 'goo'
      ∇ foo;⎕IO       ∇ goo;⎕IO     
 [1]    ⎕IO←0    [1]    ⎕IO←1       
 [2]    goo      [2]    ⎕STATE'⎕IO' 
      ∇               ∇             

       foo
 1 1  0 0  ¯1 ¯1  0 1