An exception trapping facility.

Examples:

  acid: +try { 1 + {} ; }
  bad rhs type +

  acid: +try { 1 + 1 ; }
  ok

  acid: +try { error("foobar") ; }
  foobar

  acid: e = try { 1 + {} ; }
  acid: print(e)
  bad rhs type +

Justification:

  The Acid testing framework I developed required
  error trapping.

philip.dye@cs.cmu.edu