I'm using OpenEars to detect numbers spoken by the user and transcribed into text. My goal is to transform the spelled out number into an NSNumber instance.
I have followed the advice of Rob in here to do that. So i'm using NSNumberFormatter and setting the numberStyle to NSNumberFormatterSpellOutStyle before I call numberFromString.
Here's what my NSNumberFormatter initialization code looks like.
_numberFormatter = [[NSNumberFormatter alloc] init];
[_numberFormatter setLocale:[NSLocale currentLocale]];
[_numberFormatter setNumberStyle:NSNumberFormatterSpellOutStyle];
[_numberFormatter setMaximumFractionDigits:2];
[_numberFormatter setMinimumFractionDigits:2];
and then I'm NSLogging the result of numberFromString for a series of examples (just for testing)
First:
NSLog(@"%@", [formatter numberFromString:@"eleven point three"]);
NSLog(@"%@", [formatter numberFromString:@"three point eleven"]);
NSLog(@"%@", [formatter numberFromString:@"three point one one"]);
and the results:
11.3
(null)
3.11
Second:
NSLog(@"%@", [formatter numberFromString:@"thirty-four"]);
NSLog(@"%@", [formatter numberFromString:@"thirty four"]);
and the results:
34
3004
Third:
NSLog(@"%@", [formatter numberFromString:@"three point one one"]);
NSLog(@"%@", [formatter numberFromString:@"one one point three"]);
and the results:
3.11
101.3
NSNumberFormatter seems to dislike anything other than single digits as decimals. It also seems to have a very strict set of rules when it comes to double digit numbers having to be separated by hyphens. And for the 3rd example it's just a mess...
Are these known limitations of NSNumberFormatter and would you have any suggestions as to overcoming this?
Are there any other limitations that I haven't encountered yet?
Many thanks for all input.
