Y must be a simple character scalar or vector, identifying the name of a function or operator, or the object representation form of a function or operator (see Object Representation ). R is a simple character matrix, with one name per row, of identified names in the function or operator in Y excluding distinguished names of system constants, variables or functions.
⎕VR'OPTIONS' ∇ OPTIONS;OPTS;INP [1] ⍝ REQUESTS AND EXECUTES AN OPTION [2] OPTS ←'INPUT' 'REPORT' 'END' [3] IN:INP←ASK'OPTION:' [4] →EX⍴⍨(⊂INP)∊OPTS [5] 'INVALID OPTION. SELECT FROM',OPTS ⋄ →IN [6] EX:→EX+OPTS⍳⊂INP [7] INPUT ⋄ →IN [8] REPORT ⋄ →IN [9] END: ∇ ⎕REFS'OPTIONS' ASK END EX IN INP INPUT OPTIONS OPTS REPORT
If Y is locked or is an External Function, R contains its name only. For example:
⎕LOCK 'OPTIONS' ⋄ ⎕REFS 'OPTIONS' OPTIONS
If Y is the name of a primitive, external or derived function, R is an empty matrix with shape 0 0.