OpenEuphoria

Re: Wrap-around search algorithm

• Posted by euphoric (admin) Apr 19, 2019
• 1536 views

Pseudo code:

This way you can even highlight all the matches, but make the current one a bright highlight:

sequence matches 
sequence lastStrFind = "" 
 
procedure find(sequence strFind = lastStrFind, integer bDirection) 
integer cursorPos = current_cursor_position() 
 
	if length(strFind) = 0 then 
		if length(lastStrFind) = 0 then 
			return 
		else 
			strFind = lastStrFind 
		end if 
	end if 
 
	matches = match_all( strFind, docText ) 
 
	if bDirection = Forward then 
		if cursorPos < matches[1] then 
			-- at the top, just go to first found 
			 
		elsif cursorPos > matches[$] then 
			-- at end of document, wrap to first in matches[] 
			 
		else 
			for t=1 to length(matches) docText 
				if matches[t] > cursorPos then 
					highlightFound( matches[t-1], length(strFind) ) 
					exit 
				end if 
			end for 
		end if 
	else 
		-- do it backwards style 
	end if 
 
	lastStrFind = strFind 
end procedure 

This way you don't have to keep the matching string in memory, but it doesn't allow you to highlight all the matches:

pos = match( strFind, docText, currentCursorPosition ) 
 
if pos = 0 then 
	pos = match( strFind, docText, 0 ) 
	if pos = 0 then 
		-- NOT FOUND 
	end if 
else 
	setHighlight( pos, length(strFind) ) 
end if 

I also like in MS VS Code how if I select text, it lightly highlights all matching text in the document. If I highlight a variable name, for example, it subtly shows me all places on the page where that variable appears. Very nice!

Looks like Notepad++ also does the selection highlighting.