Fix binary search in find_dict_prefix() - #356
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The
find_dict_prefix()function searches for dictionary words so it can replace them as escapes in the WRIT chunk. There was an off-by-one bug in the binary search code that made it miss most of the matches. It also made a wrong assumption about the string ordering, say we have this dictionary:If we try to find a prefix for "cloaks" we should find "cloak" but the insertion point for "cloaks" is to the right of "cloakroom" so it'll never go there. The solution is to repeat the binary search on prefixes of a given length, starting with the longest dictionary word length.
These two fixes reduce the size of the example stories by 2 or 3 percent.