How to specify Future type correctly
0
I'm trying to figure out how to specify types in code like this:
import 'dart:convert';
import 'package:http/http.dart' as http;
main() async {
Map repos = await(fetchJson());
print(repos['name']);
}
Object fetchJson() async {
final uri = 'https://api.github.com/users/sjindel-google/repos';
final response = await http.get(uri);
return jsonDecode(response.body)[1];
}
That code works, but I want to specify the type for fetchJson(). It seems like it should be:
Future<Map> fetchJson() async {
But that gives me the runtime error:
Error: 'Future' expects 0 type arguments.
What's the right way to do this?
dart dart-async
asked Nov 25 '18 at 20:49
Jim GreerJim Greer
12
add a comment |
0
I'm trying to figure out how to specify types in code like this:
import 'dart:convert';
import 'package:http/http.dart' as http;
main() async {
Map repos = await(fetchJson());
print(repos['name']);
}
Object fetchJson() async {
final uri = 'https://api.github.com/users/sjindel-google/repos';
final response = await http.get(uri);
return jsonDecode(response.body)[1];
}
That code works, but I want to specify the type for fetchJson(). It seems like it should be:
Future<Map> fetchJson() async {
But that gives me the runtime error:
Error: 'Future' expects 0 type arguments.
What's the right way to do this?
dart dart-async
asked Nov 25 '18 at 20:49
Jim GreerJim Greer
12
1
Never mind. I forgot to import 'dart:async'. Not a helpful error message.
– Jim Greer
Nov 25 '18 at 21:10
1
Soon importingdart:asyncforFutureorStreamwon't be necessary anymore.
– Günter Zöchbauer
Nov 25 '18 at 21:39
That's great, thanks Gunter.
– Jim Greer
Nov 25 '18 at 22:07
add a comment |
0
0
0
I'm trying to figure out how to specify types in code like this:
import 'dart:convert';
import 'package:http/http.dart' as http;
main() async {
Map repos = await(fetchJson());
print(repos['name']);
}
Object fetchJson() async {
final uri = 'https://api.github.com/users/sjindel-google/repos';
final response = await http.get(uri);
return jsonDecode(response.body)[1];
}
That code works, but I want to specify the type for fetchJson(). It seems like it should be:
Future<Map> fetchJson() async {
But that gives me the runtime error:
Error: 'Future' expects 0 type arguments.
What's the right way to do this?
dart dart-async
asked Nov 25 '18 at 20:49
Jim GreerJim Greer
12
I'm trying to figure out how to specify types in code like this:
import 'dart:convert';
import 'package:http/http.dart' as http;
main() async {
Map repos = await(fetchJson());
print(repos['name']);
}
Object fetchJson() async {
final uri = 'https://api.github.com/users/sjindel-google/repos';
final response = await http.get(uri);
return jsonDecode(response.body)[1];
}
That code works, but I want to specify the type for fetchJson(). It seems like it should be:
Future<Map> fetchJson() async {
But that gives me the runtime error:
Error: 'Future' expects 0 type arguments.
What's the right way to do this?
dart dart-async
dart dart-async
asked Nov 25 '18 at 20:49
Jim GreerJim Greer
12
asked Nov 25 '18 at 20:49
Jim GreerJim Greer
12
asked Nov 25 '18 at 20:49
Jim GreerJim Greer
12
asked Nov 25 '18 at 20:49
Jim GreerJim Greer
12
asked Nov 25 '18 at 20:49
Jim GreerJim Greer
12
12
1
Never mind. I forgot to import 'dart:async'. Not a helpful error message.
– Jim Greer
Nov 25 '18 at 21:10
1
Soon importingdart:asyncforFutureorStreamwon't be necessary anymore.
– Günter Zöchbauer
Nov 25 '18 at 21:39
That's great, thanks Gunter.
– Jim Greer
Nov 25 '18 at 22:07
add a comment |
1
Never mind. I forgot to import 'dart:async'. Not a helpful error message.
– Jim Greer
Nov 25 '18 at 21:10
1
Soon importingdart:asyncforFutureorStreamwon't be necessary anymore.
– Günter Zöchbauer
Nov 25 '18 at 21:39
That's great, thanks Gunter.
– Jim Greer
Nov 25 '18 at 22:07
1
1
Never mind. I forgot to import 'dart:async'. Not a helpful error message.
– Jim Greer
Nov 25 '18 at 21:10
Never mind. I forgot to import 'dart:async'. Not a helpful error message.
– Jim Greer
Nov 25 '18 at 21:10
1
1
Soon importing
dart:async for Future or Stream won't be necessary anymore.– Günter Zöchbauer
Nov 25 '18 at 21:39
Soon importing
dart:async for Future or Stream won't be necessary anymore.– Günter Zöchbauer
Nov 25 '18 at 21:39
That's great, thanks Gunter.
– Jim Greer
Nov 25 '18 at 22:07
That's great, thanks Gunter.
– Jim Greer
Nov 25 '18 at 22:07
add a comment |
0
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1
Never mind. I forgot to import 'dart:async'. Not a helpful error message.
– Jim Greer
Nov 25 '18 at 21:10
1
Soon importing
dart:asyncforFutureorStreamwon't be necessary anymore.– Günter Zöchbauer
Nov 25 '18 at 21:39
That's great, thanks Gunter.
– Jim Greer
Nov 25 '18 at 22:07