RWT: Error handling

REBOL [ Title: "Error handling code" ] handle: func [ {Executes a code block with optional error handling.} [catch] code [ any-block!] {The code to be evaluated} /with {Specify a code block that acts as an error handler.} handler [block!] {The code block that handles the error.} /pass-to {Specify a function that acts as an error handler. A disarmed error is passed to this function, so it must expect a single object argument.} f [function!] {The function that handles the error.} /pass-params {Pass optional parameter block to the error handler.} params [block!] {Block containing parameters.} /transparent {Rethrows any caught error after executing the handler(s).} /local result disarmed ] [ ; Try to execute the code. if error? set/any 'result try code [ ; If an error occurs, handle it in accordance with the refinements, ; otherwise, return the value returned by the code block disarmed: disarm result ; Do we have a handler function? if pass-to [ either pass-params [ f disarmed params ][ f disarmed ] ] ; Is there a code block to handle the error? if with [ bind handler 'disarmed do handler ] ; Optionally rethrow the error. if transparent [ result ] return none ] get/any 'result ]