[mkgmap-dev] multi-word street search

Tue Feb 26 05:50:25 GMT 2013

On Mon, Feb 25, 2013 at 10:55:32PM +0200, Rich wrote:
>it might require implementing a list of "street" names for each 
>country.
>in many cases for streets named after some person people would want to 
>refer to it by both first and last name, but "street" wouldn't be 
>useful at all

This sounds like full-text search (inverted index). Each word in the 
street name would become an index entry.

If we have street names "Calle b c" (id 1) and "Calle c d" (id 2) then 
we would have index entries like this:

Calle -> 1
Calle -> 2
b -> 1
c -> 1
c -> 2
d -> 2

In full-text search, common words such as 'a' or 'the' are often treated 
as useless garbage and thrown away both when indexing and when 
searching. These words are commonly referred to as stop-words. mkgmap 
could implement a stop-word list in country-specific rules, similar to 
how we set the flags for formatting addresses. This list could be 
something like 'Street,St,Ave,Lane' for English-speaking countries.

As far as I understand, mkgmap could easily do this splitting and 
stop-word implementation.

Do Garmin devices implement multi-word street search? What happens if 
the user types "Main Street"? Will it search for either Main or Street, 
or both?

	Marko