MODIFIED: prompt/2 now throws an exception if the second argument is invalid.
MODIFIED: prompt/2 now throws an exception if the second argument is invalid.

Previous versions failed silently.

mndrix/swipl-devel,mndrix/swipl-devel,koryonik/swipl-devel,jn7163/swipl-devel,mndrix/swipl-devel,edechter/swipl-devel,mndrix/swipl-devel,koryonik/swipl-devel,koryonik/swipl-devel,jn7163/swipl-devel,edechter/swipl-devel,koryonik/swipl-devel,edechter/swipl-devel,jn7163/swipl-devel,jn7163/swipl-devel,koryonik/swipl-devel,edechter/swipl-devel,jn7163/swipl-devel,mndrix/swipl-devel,edechter/swipl-devel