$::error -- Error Handling

$::error::ea -- Execute Alternate

Dyadic. Both arguments are character vectors containing APL expressions. Tries the right expression; if it raises an APL error, evaluates the left expression instead.

Syntax

      'fallback' $::error::ea 'expression'

Examples

      '0' $::error::ea '2+3'
5
      '0' $::error::ea '1÷0'
0

The error code from a caught error is stored for $::error::en:

      '¯1' $::error::ea '1÷0'
¯1
      $::error::en 0
3

Notes

Both arguments are evaluated as strings, not as APL values. This is similar to Dyalog's ⎕EA.

$::error::en -- Error Number

Monadic. Returns the error code of the most recent caught error, or 0 if no error has occurred. The argument is ignored (pass any scalar).

Syntax

      $::error::en 0

Error codes

Code	Error
1	SYNTAX ERROR
2	VALUE ERROR
3	DOMAIN ERROR
4	LENGTH ERROR
5	RANK ERROR
6	INDEX ERROR
7	LIMIT ERROR
8	WS FULL
9	SECURITY ERROR
10	DEPENDENCY ERROR
11	CLASS ERROR

Implementation

      ea←{⍺ (⌶'marple.stdlib.error_impl.ea') ⍵}
      en←{(⌶'marple.stdlib.error_impl.en') ⍵}