diff options
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 29 |
1 files changed, 16 insertions, 13 deletions
@@ -28237,14 +28237,17 @@ macro. If no catch or accepting handler is found, control is transferred to the function stored in the .code *unhandled-hook* -variable. If that function returns, the process terminates. +variable. If that function returns, then unwinding is performed +after which the process terminates (unless the unwinding actions +intercept the control to prevent that). .IP - If no catch or accepting handler is found and .code *unhandled-hook* is .codn nil , then a built-in strategy for handling the exception is invoked, -consisting of printing some informational messages and terminating. +consisting of unwinding, and then printing some informational messages and +terminating. .PP From the above it should be evident that there are two ways by which exceptions @@ -28674,25 +28677,25 @@ with the following arguments: the exception type symbol, the exception object, and a third value which is either .code nil or else the form which was being evaluated when the exception was thrown. +The call occurs before any unwinding takes place. -Otherwise, if the variable is +If the variable is +.codn nil , +or isn't a function, or the function returns after being called, +then unwinding takes place, after which some informational messages are printed +about the exception, and the process exits with a failed termination status. + +In the case when the variable contains a object other than .code nil -some informational messages are printed about the exception, and the process -exits with a failed termination status. -In the same situation, if the variable contains an object which is not a -function, the process terminates abnormally as if by a call to the -.code abort -function. +which isn't a function, a diagnostic message is printed on the +.code *stderr* +stream prior to unwinding. Prior to the function being called, the .code *unhandled-hook* variable is reset to .codn nil . -If the function registered in -.code *unhandled-hook* -returns, the process exits with a failed termination status. - Note: the functions .code source-loc or |