foldLeft method in scala -

i using following code count of words in text

.foldleft(map.empty[string, float]){    (countssource, wordsource) => countssource + (wordsource -> (countssource.getorelse(wordsource, 0) + 1))} 

i getting error 1 should string. if put in quotes, says should float.

what doing wrong?? in advance

getorelse's signature follows:

def getorelse[b1 >: b](key: a, default: => b1): b1 

which means doesn't return type of map's value (b), potentially superclass b1. in case, using literal 0 doesn't inform compiler you're interested in float.

using 0f instead fix it:

l.foldleft(map.empty[string, float]){   (countssource, wordsource) => countssource + (wordsource -> (countssource.getorelse(wordsource, 0f) + 1))}