Using Span as a replacement for Substring
I have read a few articles about how Span can be used to replace certain string operations. As such I have updated some code in my code base to use this new feature, however, to be able to use it in-place I then have to call .ToString().
Does the .ToString() effectively negate the benefit I get from using Span<T> rather than Substring as this would have to allocate memory? In which case how do I reap the benefits if Span in this way, or is it just not possible?
//return geofenceNamesString.Substring(0, 50); Previous code
return geofenceNamesString.AsSpan().Slice(0, 50).ToString();
c# substring system.memory
edited Jan 1 at 19:28
Daniel A. White
149k36296375
asked Jan 1 at 18:28
ChrisChris
14.5k38151277
add a comment |
I have read a few articles about how Span can be used to replace certain string operations. As such I have updated some code in my code base to use this new feature, however, to be able to use it in-place I then have to call .ToString().
Does the .ToString() effectively negate the benefit I get from using Span<T> rather than Substring as this would have to allocate memory? In which case how do I reap the benefits if Span in this way, or is it just not possible?
//return geofenceNamesString.Substring(0, 50); Previous code
return geofenceNamesString.AsSpan().Slice(0, 50).ToString();
c# substring system.memory
edited Jan 1 at 19:28
Daniel A. White
149k36296375
asked Jan 1 at 18:28
ChrisChris
14.5k38151277
2
Yes; creating aStringnegates the benefit by allocating a string. You need to return aSpan<T>
– SLaks
Jan 1 at 18:30
My ultimate use of this is to store it in a database via EF, which is string type, I guess then I won't see the benefit for this particular use case?
– Chris
Jan 1 at 18:30
add a comment |
I have read a few articles about how Span can be used to replace certain string operations. As such I have updated some code in my code base to use this new feature, however, to be able to use it in-place I then have to call .ToString().
Does the .ToString() effectively negate the benefit I get from using Span<T> rather than Substring as this would have to allocate memory? In which case how do I reap the benefits if Span in this way, or is it just not possible?
//return geofenceNamesString.Substring(0, 50); Previous code
return geofenceNamesString.AsSpan().Slice(0, 50).ToString();
c# substring system.memory
edited Jan 1 at 19:28
Daniel A. White
149k36296375
asked Jan 1 at 18:28
ChrisChris
14.5k38151277
I have read a few articles about how Span can be used to replace certain string operations. As such I have updated some code in my code base to use this new feature, however, to be able to use it in-place I then have to call .ToString().
Does the .ToString() effectively negate the benefit I get from using Span<T> rather than Substring as this would have to allocate memory? In which case how do I reap the benefits if Span in this way, or is it just not possible?
//return geofenceNamesString.Substring(0, 50); Previous code
return geofenceNamesString.AsSpan().Slice(0, 50).ToString();
c# substring system.memory
c# substring system.memory
edited Jan 1 at 19:28
Daniel A. White
149k36296375
asked Jan 1 at 18:28
ChrisChris
14.5k38151277
edited Jan 1 at 19:28
Daniel A. White
149k36296375
asked Jan 1 at 18:28
ChrisChris
14.5k38151277
edited Jan 1 at 19:28
Daniel A. White
149k36296375
edited Jan 1 at 19:28
Daniel A. White
149k36296375
edited Jan 1 at 19:28
Daniel A. White
149k36296375
149k36296375
asked Jan 1 at 18:28
ChrisChris
14.5k38151277
asked Jan 1 at 18:28
ChrisChris
14.5k38151277
asked Jan 1 at 18:28
ChrisChris
14.5k38151277
14.5k38151277
2
Yes; creating aStringnegates the benefit by allocating a string. You need to return aSpan<T>
– SLaks
Jan 1 at 18:30
My ultimate use of this is to store it in a database via EF, which is string type, I guess then I won't see the benefit for this particular use case?
– Chris
Jan 1 at 18:30
add a comment |
2
Yes; creating aStringnegates the benefit by allocating a string. You need to return aSpan<T>
– SLaks
Jan 1 at 18:30
My ultimate use of this is to store it in a database via EF, which is string type, I guess then I won't see the benefit for this particular use case?
– Chris
Jan 1 at 18:30
2
2
Yes; creating a
String negates the benefit by allocating a string. You need to return a Span<T>– SLaks
Jan 1 at 18:30
Yes; creating a
String negates the benefit by allocating a string. You need to return a Span<T>– SLaks
Jan 1 at 18:30
My ultimate use of this is to store it in a database via EF, which is string type, I guess then I won't see the benefit for this particular use case?
– Chris
Jan 1 at 18:30
My ultimate use of this is to store it in a database via EF, which is string type, I guess then I won't see the benefit for this particular use case?
– Chris
Jan 1 at 18:30
add a comment |
1 Answer
1
active
oldest
votes
There is no benefit in your case.
A span is useful if you keep multiple "references" into the same array of data. For example if you read a file into RAM and then kept references to each line, so you don't have to copy each line, but only to keep its position in the big string.
You are making a copy of your string one way or another. So just go with the easier, more readable way of Substring.
edited Jan 1 at 18:55
Nyerguds
3,08111838
answered Jan 1 at 18:33
nvoigtnvoigt
49.9k85692
add a comment |
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1 Answer
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active
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votes
There is no benefit in your case.
A span is useful if you keep multiple "references" into the same array of data. For example if you read a file into RAM and then kept references to each line, so you don't have to copy each line, but only to keep its position in the big string.
You are making a copy of your string one way or another. So just go with the easier, more readable way of Substring.
edited Jan 1 at 18:55
Nyerguds
3,08111838
answered Jan 1 at 18:33
nvoigtnvoigt
49.9k85692
add a comment |
There is no benefit in your case.
A span is useful if you keep multiple "references" into the same array of data. For example if you read a file into RAM and then kept references to each line, so you don't have to copy each line, but only to keep its position in the big string.
You are making a copy of your string one way or another. So just go with the easier, more readable way of Substring.
edited Jan 1 at 18:55
Nyerguds
3,08111838
answered Jan 1 at 18:33
nvoigtnvoigt
49.9k85692
add a comment |
There is no benefit in your case.
A span is useful if you keep multiple "references" into the same array of data. For example if you read a file into RAM and then kept references to each line, so you don't have to copy each line, but only to keep its position in the big string.
You are making a copy of your string one way or another. So just go with the easier, more readable way of Substring.
edited Jan 1 at 18:55
Nyerguds
3,08111838
answered Jan 1 at 18:33
nvoigtnvoigt
49.9k85692
There is no benefit in your case.
A span is useful if you keep multiple "references" into the same array of data. For example if you read a file into RAM and then kept references to each line, so you don't have to copy each line, but only to keep its position in the big string.
You are making a copy of your string one way or another. So just go with the easier, more readable way of Substring.
edited Jan 1 at 18:55
Nyerguds
3,08111838
answered Jan 1 at 18:33
nvoigtnvoigt
49.9k85692
edited Jan 1 at 18:55
Nyerguds
3,08111838
edited Jan 1 at 18:55
Nyerguds
3,08111838
edited Jan 1 at 18:55
Nyerguds
3,08111838
3,08111838
answered Jan 1 at 18:33
nvoigtnvoigt
49.9k85692
answered Jan 1 at 18:33
nvoigtnvoigt
49.9k85692
answered Jan 1 at 18:33
nvoigtnvoigt
49.9k85692
49.9k85692
add a comment |
add a comment |
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2
Yes; creating a
Stringnegates the benefit by allocating a string. You need to return aSpan<T>– SLaks
Jan 1 at 18:30
My ultimate use of this is to store it in a database via EF, which is string type, I guess then I won't see the benefit for this particular use case?
– Chris
Jan 1 at 18:30