[TEXT-188] Speed up LevenshteinDistance with threshold

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.9
• Fix Version/s: 1.10.0
• Assignee: Bruno P. Kinoshita
• Reporter: Jakob Vesterstrøm
• Created: 02/Oct/20 08:56
• Updated: 05/Oct/20 09:34
• Resolved: 04/Oct/20 23:07

Description

The calculation made by the LevenshteinDistance class can often be made faster, when the class in initialized with a threshold, and when the distance is found to be larger than the threshold. In those cases, it is often not necessary to iterate through the whole string, since a lower bound for the result can be established after each iteration. If that lower bound is larger than the threshold, the method can simply exit early with the same result as without this improvement. 

A patch with the proposed change is attached to this issue.