2000-06-26  JP Rosevear  <jpr@arcavia.com>

	* src/value.c (value_get_as_checked_bool): New function that
	doesn't require an error variable - use only if confident that
	the value does actually exist.

	* src/value.h: Add new prototype.

	* src/functions/fn-lookup.c: Clean up cruft
	(find_type_valid): See if the value is a string or is gnumeric.
	(find_compare_type_valid): See if the types are comparable.
	(find_bound_walk): Walk an integer range first in one direction
	and then in the other direction.
	(find_index_linear): Do a linear search on a range or array.
	(find_index_bisection): Do a bisection search on a range or array
	that also follows excel rules for for handling type mismatches
	during the search and finding the first and last item matching
	the search.
	(gnumeric_vlookup): Use new functions and implement undocumented
	excel behaviour.
	(gnumeric_hlookup): ditto
	(gnumeric_lookup): ditto
	(gnumeric_match): ditto