In .NET enumeration is slow
-
Well, the first call (GetEnumerator) definitely has a penalty, but each retrieval after that (each call to the enumerator) may be as quick as an indexed access... or it may not be. Anyway, I agree with -- if you know you're iterating across an array, use array access instead. And don't use Linq.
Just to be difficult, I'd argue that an Enumerator - even a special cased one like the implementation on System.String will be slower than indexed access. The reason being is that it's necessary to execute an additional call to MoveNext() for each advance, whereas with indexed access you are simply incrementing a value. You must then call Current to get the actual value. I haven't benchmarked it, but I'd be very surprised if this was not the case.
Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
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I just switched IEnumerable to IList and removed foreach (preferring for) and cut my execution time in my test from 65ms to about 45ms. I've put a stripped down version of the code here. The first argument of each emphasized routine was IEnumerable, is now IList with no foreach. This, ladies and gents, is why I don't like LINQ.
// here this._fa is the target machine we will be parsing.
// parse this or otherwise build it and use it here.
IList initial = FA.FillEpsilonClosure(this._fa);
IList next = new List();
IList states = new List(initial);
// start out with an empty capture buffer
this.capture.Clear();
// first move:
if (this.current == -2)
{
this.Advance();
}
// store the current position
long cursor_pos = this.position;
int line = this.line;
int column = this.column;
while(true) {
// try to transition from states on
// the current codepoint under the
// cursor
next.Clear();
FA.FillMove(states, this.current, next);
if (next.Count > 0)
{
// found at least one transition
// capture the current
// char, advance the input
// position:
this.Advance();
// move to the next states
states.Clear();
FA.FillEpsilonClosure(next, states);
} else {
// no matching transition
// is any current state accepting?
int acc = FA.GetFirstAcceptSymbol(states);
if(acc>-1) {
// accept
return FAMatch.Create(
acc,
this.capture.ToString(),
cursor_pos,
line,
column);
}
// not accepting - error
// keep capturing input until we find a
// valid move or there's no more input
while (this.current != -1 &&
FA.FillMove(initial, this.current).Count == 0)
{
this.Advance();
}
if (capture.Length == 0)
{
// end of input
return FAMatch.Create(-2, null, 0, 0, 0);
}
// error
return FAMatch.Create(-1,
capture.ToString(),
cursor_pos,
line,
column);}}
Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
I use ICollection in the absence of any other requirements. [https://stackoverflow.com/questions/10113244/why-use-icollection-and-not-ienumerable-or-listt-on-many-many-one-many-relatio\](https://stackoverflow.com/questions/10113244/why-use-icollection-and-not-ienumerable-or-listt-on-many-many-one-many-relatio)
"Before entering on an understanding, I have meditated for a long time, and have foreseen what might happen. It is not genius which reveals to me suddenly, secretly, what I have to say or to do in a circumstance unexpected by other people; it is reflection, it is meditation." - Napoleon I
-
I just switched IEnumerable to IList and removed foreach (preferring for) and cut my execution time in my test from 65ms to about 45ms. I've put a stripped down version of the code here. The first argument of each emphasized routine was IEnumerable, is now IList with no foreach. This, ladies and gents, is why I don't like LINQ.
// here this._fa is the target machine we will be parsing.
// parse this or otherwise build it and use it here.
IList initial = FA.FillEpsilonClosure(this._fa);
IList next = new List();
IList states = new List(initial);
// start out with an empty capture buffer
this.capture.Clear();
// first move:
if (this.current == -2)
{
this.Advance();
}
// store the current position
long cursor_pos = this.position;
int line = this.line;
int column = this.column;
while(true) {
// try to transition from states on
// the current codepoint under the
// cursor
next.Clear();
FA.FillMove(states, this.current, next);
if (next.Count > 0)
{
// found at least one transition
// capture the current
// char, advance the input
// position:
this.Advance();
// move to the next states
states.Clear();
FA.FillEpsilonClosure(next, states);
} else {
// no matching transition
// is any current state accepting?
int acc = FA.GetFirstAcceptSymbol(states);
if(acc>-1) {
// accept
return FAMatch.Create(
acc,
this.capture.ToString(),
cursor_pos,
line,
column);
}
// not accepting - error
// keep capturing input until we find a
// valid move or there's no more input
while (this.current != -1 &&
FA.FillMove(initial, this.current).Count == 0)
{
this.Advance();
}
if (capture.Length == 0)
{
// end of input
return FAMatch.Create(-2, null, 0, 0, 0);
}
// error
return FAMatch.Create(-1,
capture.ToString(),
cursor_pos,
line,
column);}}
Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
Well, yes, and no. The answer is it depends on which Framework and version that you are using. This video will expand on this: Microsoft FINALLY fixed foreach loops in .NET 7 - YouTube[^]
Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
-
I use ICollection in the absence of any other requirements. [https://stackoverflow.com/questions/10113244/why-use-icollection-and-not-ienumerable-or-listt-on-many-many-one-many-relatio\](https://stackoverflow.com/questions/10113244/why-use-icollection-and-not-ienumerable-or-listt-on-many-many-one-many-relatio)
"Before entering on an understanding, I have meditated for a long time, and have foreseen what might happen. It is not genius which reveals to me suddenly, secretly, what I have to say or to do in a circumstance unexpected by other people; it is reflection, it is meditation." - Napoleon I
If I don't care about access performance in general I will use
IEnumerable<T>if I can rather than a collection. The reason being is (A) I don't like to impose functionality I'm not going to use and enumerating a collection is the same as enumerating with IEnumerable. (B) Lazy loading isn't really doable with collections in most circumstances because of the presence of count. (C) Collections provide methods to modify them. I certainly don't like suggesting I will modify something I won't, so if i can take the immutable version for a read only function i will. (D) unbounded collections are not supported by .NET collections. You must know the count ahead of time. My choice of switching to IList was improved index access performance. ICollection doesn't provide that.Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
-
Well, yes, and no. The answer is it depends on which Framework and version that you are using. This video will expand on this: Microsoft FINALLY fixed foreach loops in .NET 7 - YouTube[^]
Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
That's interesting! I'm currently targeting .NET 6 but I will keep that in mind. Thanks.
Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
-
That's interesting! I'm currently targeting .NET 6 but I will keep that in mind. Thanks.
Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
It's a simple move from .Net 6.* to to .Net 8.* too... I feel sorry for those stuck in the .Net Framework world, they lose out on all of the performance improvements, in most cases, by simply switching and recompiling.
Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
-
It's a simple move from .Net 6.* to to .Net 8.* too... I feel sorry for those stuck in the .Net Framework world, they lose out on all of the performance improvements, in most cases, by simply switching and recompiling.
Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
Waaaa! I'm stuck in the framework right now.
The difficult we do right away... ...the impossible takes slightly longer.
-
It's a simple move from .Net 6.* to to .Net 8.* too... I feel sorry for those stuck in the .Net Framework world, they lose out on all of the performance improvements, in most cases, by simply switching and recompiling.
Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
I recently made my Visual FA solution target the .NET Framework in addition to Core and Standard. So I have VisualFA.csproj and VisualFA.DNF.csproj. The latter is the same project but for DNF. All the source files are linked via "Add as link" from the first project so I only have one copy. I then use a conditional compilation constant to add or remove the use of spans in code since .NET framework and as far as I can tell, VB.NET don't support them.
Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
-
I recently made my Visual FA solution target the .NET Framework in addition to Core and Standard. So I have VisualFA.csproj and VisualFA.DNF.csproj. The latter is the same project but for DNF. All the source files are linked via "Add as link" from the first project so I only have one copy. I then use a conditional compilation constant to add or remove the use of spans in code since .NET framework and as far as I can tell, VB.NET don't support them.
Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
VB.Net supports both frameworks. If you look at my most recent articles, here on CodeProject, I support C# & VB.Net on .Net Core & .Net Frsmework. However, almost 12 months ago, there was a change. This Microsoft blog post explains: Update to the .NET language strategy - .NET Blog[^]
Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
-
VB.Net supports both frameworks. If you look at my most recent articles, here on CodeProject, I support C# & VB.Net on .Net Core & .Net Frsmework. However, almost 12 months ago, there was a change. This Microsoft blog post explains: Update to the .NET language strategy - .NET Blog[^]
Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
I realize it supports both frameworks. I'm saying it doesn't seem to support spans, and I don't think ReadOnlySpan is marked obsolete, but I haven't looked 'ReadOnlySpan(Of Char)' is obsolete: 'Types with embedded references are not supported in this version of your compiler.'. Does not compile. I get the above
Private Function _BlockEnd0(ByVal s As ReadOnlySpan(Of Char), ByVal cp As Integer, ByVal len As Integer, ByVal position As Integer, ByVal line As Integer, ByVal column As Integer) As FAMatch
Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
-
I realize it supports both frameworks. I'm saying it doesn't seem to support spans, and I don't think ReadOnlySpan is marked obsolete, but I haven't looked 'ReadOnlySpan(Of Char)' is obsolete: 'Types with embedded references are not supported in this version of your compiler.'. Does not compile. I get the above
Private Function _BlockEnd0(ByVal s As ReadOnlySpan(Of Char), ByVal cp As Integer, ByVal len As Integer, ByVal position As Integer, ByVal line As Integer, ByVal column As Integer) As FAMatch
Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
Yes, covered in that blog post. However, a C# facade library can address that limitation. Performace wise, VB.Net is just as fast as C# on both frameworks. My latest JSON Streaming[^] article has the benchmarks to prove it. That too uses
ReadOnlySpanandref strutwithasync/await. I mention the VB.Net limitation in the article. ;P Sadly, I think that the article was too much for most readers.Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
-
Yes, covered in that blog post. However, a C# facade library can address that limitation. Performace wise, VB.Net is just as fast as C# on both frameworks. My latest JSON Streaming[^] article has the benchmarks to prove it. That too uses
ReadOnlySpanandref strutwithasync/await. I mention the VB.Net limitation in the article. ;P Sadly, I think that the article was too much for most readers.Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
That's great for your situation. In my current scenario this code was generated by a tool, and specifically designed to be able to produce dependency free code. I might actually consider the facade idea though for when it is opted to rely on the runtimes - right now the VB code can't under the newer frameworks unless you turn off spans in the compiled runtime itself - the build - not at runtime - it's conditionally compiled in. So that facade may fix that issue. And yet otherwise in my tests, the spanless string approach i use (Substring instead of Splice) doesn't yield noticeably less performance. That leads me to suspect I'm not using it to its fullest - an encouraging thought in the big picture because it means I can get even more speed out of it. I'm not sure that's possible though because no matter how I think about approaching it a copy is always necessary by the time you hit the
Valueproperty offFAMatch. It's a head scratcher.Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
-
That's great for your situation. In my current scenario this code was generated by a tool, and specifically designed to be able to produce dependency free code. I might actually consider the facade idea though for when it is opted to rely on the runtimes - right now the VB code can't under the newer frameworks unless you turn off spans in the compiled runtime itself - the build - not at runtime - it's conditionally compiled in. So that facade may fix that issue. And yet otherwise in my tests, the spanless string approach i use (Substring instead of Splice) doesn't yield noticeably less performance. That leads me to suspect I'm not using it to its fullest - an encouraging thought in the big picture because it means I can get even more speed out of it. I'm not sure that's possible though because no matter how I think about approaching it a copy is always necessary by the time you hit the
Valueproperty offFAMatch. It's a head scratcher.Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
Quote:
And yet otherwise in my tests, the spanless string approach i use (Substring instead of Splice) doesn't yield noticeably less performance. That leads me to suspect I'm not using it to its fullest - an encouraging thought in the big picture because it means I can get even more speed out of it. I'm not sure that's possible though because no matter how I think about approaching it a copy is always necessary by the time you hit the Value property off FAMatch. It's a head scratcher.
Without knowing specifics, it is difficult to comment. That article is about dealing with gigabytes of data using streams efficiently keeping allocations to a minimum. There was a lot of research, trial & error done to find the best optimal solution. I even looked at the source code of Microsoft's latest (At the time) .Net Core. Renting ReadOnlyMemory[^] was not suitable as all memory blocks needed to be of the same size otherwise nulls fill the gaps. This is not documented anywhere! And I did look. That was a real headscratcher at the time. Don't get me started on
ref strutin an asynchronous environment... I'm sure if you take a step back, do a bit of research, experimenting, digging into the Microsoft code, you will find a solution.Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
-
Quote:
And yet otherwise in my tests, the spanless string approach i use (Substring instead of Splice) doesn't yield noticeably less performance. That leads me to suspect I'm not using it to its fullest - an encouraging thought in the big picture because it means I can get even more speed out of it. I'm not sure that's possible though because no matter how I think about approaching it a copy is always necessary by the time you hit the Value property off FAMatch. It's a head scratcher.
Without knowing specifics, it is difficult to comment. That article is about dealing with gigabytes of data using streams efficiently keeping allocations to a minimum. There was a lot of research, trial & error done to find the best optimal solution. I even looked at the source code of Microsoft's latest (At the time) .Net Core. Renting ReadOnlyMemory[^] was not suitable as all memory blocks needed to be of the same size otherwise nulls fill the gaps. This is not documented anywhere! And I did look. That was a real headscratcher at the time. Don't get me started on
ref strutin an asynchronous environment... I'm sure if you take a step back, do a bit of research, experimenting, digging into the Microsoft code, you will find a solution.Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
I feel like it might be chasing ghosts, particularly since I already get really great performance out of the thing, especially compared to .NET Regex even though that always uses ReadOnlySpan. I still beat it by 3x in the best case.
Microsoft Regex "Lexer": [■■■■■■■■■■] 100% Found 220000 matches in 35ms
Microsoft Regex compiled "Lexer": [■■■■■■■■■■] 100% Found 220000 matches in 20ms
FAStringRunner (proto): [■■■■■■■■■■] 100% Found 220000 matches in 7ms
FATextReaderRunner: (proto) [■■■■■■■■■■] 100% Found 220000 matches in 13ms
FAStringDfaTableRunner: [■■■■■■■■■■] 100% Found 220000 matches in 10ms
FATextReaderDfaTableRunner: [■■■■■■■■■■] 100% Found 220000 matches in 14ms
FAStringStateRunner (NFA): [■■■■■■■■■■] 100% Found 220000 matches in 145ms
FAStringStateRunner (Compact NFA): [■■■■■■■■■■] 100% Found 220000 matches in 43ms
FATextReaderStateRunner (Compact NFA): [■■■■■■■■■■] 100% Found 220000 matches in 48ms
FAStringStateRunner (DFA): [■■■■■■■■■■] 100% Found 220000 matches in 11ms
FATextReaderStateRunner (DFA): [■■■■■■■■■■] 100% Found 220000 matches in 16ms
FAStringRunner (Compiled): [■■■■■■■■■■] 100% Found 220000 matches in 7ms
FATextReaderRunner (Compiled): [■■■■■■■■■■] 100% Found 220000 matches in 12ms7ms is about what I get compared to microsoft's 20 if I'm making the fairest comparison possible (apples vs apples) 'cept mine doesn't backtrack or support a bunch of fluff. (though it lacks anchors :( ) If I can't get another 10% out of this I don't think it's worth the trouble.
Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
-
I feel like it might be chasing ghosts, particularly since I already get really great performance out of the thing, especially compared to .NET Regex even though that always uses ReadOnlySpan. I still beat it by 3x in the best case.
Microsoft Regex "Lexer": [■■■■■■■■■■] 100% Found 220000 matches in 35ms
Microsoft Regex compiled "Lexer": [■■■■■■■■■■] 100% Found 220000 matches in 20ms
FAStringRunner (proto): [■■■■■■■■■■] 100% Found 220000 matches in 7ms
FATextReaderRunner: (proto) [■■■■■■■■■■] 100% Found 220000 matches in 13ms
FAStringDfaTableRunner: [■■■■■■■■■■] 100% Found 220000 matches in 10ms
FATextReaderDfaTableRunner: [■■■■■■■■■■] 100% Found 220000 matches in 14ms
FAStringStateRunner (NFA): [■■■■■■■■■■] 100% Found 220000 matches in 145ms
FAStringStateRunner (Compact NFA): [■■■■■■■■■■] 100% Found 220000 matches in 43ms
FATextReaderStateRunner (Compact NFA): [■■■■■■■■■■] 100% Found 220000 matches in 48ms
FAStringStateRunner (DFA): [■■■■■■■■■■] 100% Found 220000 matches in 11ms
FATextReaderStateRunner (DFA): [■■■■■■■■■■] 100% Found 220000 matches in 16ms
FAStringRunner (Compiled): [■■■■■■■■■■] 100% Found 220000 matches in 7ms
FATextReaderRunner (Compiled): [■■■■■■■■■■] 100% Found 220000 matches in 12ms7ms is about what I get compared to microsoft's 20 if I'm making the fairest comparison possible (apples vs apples) 'cept mine doesn't backtrack or support a bunch of fluff. (though it lacks anchors :( ) If I can't get another 10% out of this I don't think it's worth the trouble.
Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
That is impressive. Have you seen the latest updates to
RegEx? Regular Expression Improvements in .NET 7 - .NET Blog[^] ... Source Generators forRegExare next level! I would dig into the source code for the changes to theRegExand the Source Generator forRegExand see how they do it to get ideas for yours.Quote:
If I can't get another 10% out of this I don't think it's worth the trouble.
I hear you, and for a one-off can agree, however, you will need to understand that last 10% for future projects. The question is now or then?
Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
-
That is impressive. Have you seen the latest updates to
RegEx? Regular Expression Improvements in .NET 7 - .NET Blog[^] ... Source Generators forRegExare next level! I would dig into the source code for the changes to theRegExand the Source Generator forRegExand see how they do it to get ideas for yours.Quote:
If I can't get another 10% out of this I don't think it's worth the trouble.
I hear you, and for a one-off can agree, however, you will need to understand that last 10% for future projects. The question is now or then?
Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
That's actually targeting Microsoft's .NET 7 implementation, and yeah I've looked at their source generator and considered making my own using the same tech. Right now I'm using the CodeDOM for that, which is older, but doesn't require near as much buy in in terms of your install base. For instance, you don't need compiler services running, and I'm not even sure how compatible it is with DNF and there are other unknowns. I need to do more research. I actually did dotNetPeek them which is how I figured out the Span stuff. I don't like their code. Frankly, I'm impressed with the code-synthesis but they still made it hard to follow, and I'm not sure if that's so beneficial. My code looks machine generated, but it's easy to follow, as state machines go:
// Matches C line comments or block comments
private FAMatch _BlockEnd0(ReadOnlySpan s, int cp, int len, int position, int line, int column) {
q0:
// [\*]
if ((cp == 42)) {
this.Advance(s, ref cp, ref len, false);
goto q1;
}
goto errorout;
q1:
// [\/]
if ((cp == 47)) {
this.Advance(s, ref cp, ref len, false);
goto q2;
}
goto errorout;
q2:
return FAMatch.Create(0, s.Slice(position, len).ToString(), position, line, column);
errorout:
if ((cp == -1)) {
return FAMatch.Create(-1, s.Slice(position, len).ToString(), position, line, column);
}
this.Advance(s, ref cp, ref len, false);
goto q0;
}
private FAMatch NextMatchImpl(ReadOnlySpan s) {
int ch;
int len;
int p;
int l;
int c;
ch = -1;
len = 0;
if ((this.position == -1)) {
this.position = 0;
}
p = this.position;
l = this.line;
c = this.column;
this.Advance(s, ref ch, ref len, true);
// q0:
// [\/]
if ((ch == 47)) {
this.Advance(s, ref ch, ref len, false);
goto q1;
}
goto errorout;
q1:
// [\*]
if ((ch == 42)) {
this.Advance(s, ref ch, ref len, false);
goto q2;
}
goto errorout;
q2:
return _BlockEnd0(s, ch, len, p, l, c);
errorout:
if (((ch == -1)
|| (ch == 47))) {
if ((len == 0)) {
return FAMatch.Create(-2, null, 0, 0, 0);
}
return FAMatch.Create(-1, s.Slice(p, len).ToString(), p, l, c);
}
this.Advance(s, ref ch, ref len, false);
goto errorout;
}Main thing that makes it tough is the use of UTF-32 codepoints instead of chars - neces
-
That is impressive. Have you seen the latest updates to
RegEx? Regular Expression Improvements in .NET 7 - .NET Blog[^] ... Source Generators forRegExare next level! I would dig into the source code for the changes to theRegExand the Source Generator forRegExand see how they do it to get ideas for yours.Quote:
If I can't get another 10% out of this I don't think it's worth the trouble.
I hear you, and for a one-off can agree, however, you will need to understand that last 10% for future projects. The question is now or then?
Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
I missed the bottom line of your post. I'll respond here. Well, this 10% is for a library, so it kind of changes the calculus of it somewhat. The 10% has a multiplier effect based on how popular the library gets, if that makes sense. I don't think the 10% would make the code that much more confusing unless it also forces me to do something to it I am unwilling to anyway. I am not looking for a total remodel at this stage given the stability and performance numbers I have.
Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
-
That's actually targeting Microsoft's .NET 7 implementation, and yeah I've looked at their source generator and considered making my own using the same tech. Right now I'm using the CodeDOM for that, which is older, but doesn't require near as much buy in in terms of your install base. For instance, you don't need compiler services running, and I'm not even sure how compatible it is with DNF and there are other unknowns. I need to do more research. I actually did dotNetPeek them which is how I figured out the Span stuff. I don't like their code. Frankly, I'm impressed with the code-synthesis but they still made it hard to follow, and I'm not sure if that's so beneficial. My code looks machine generated, but it's easy to follow, as state machines go:
// Matches C line comments or block comments
private FAMatch _BlockEnd0(ReadOnlySpan s, int cp, int len, int position, int line, int column) {
q0:
// [\*]
if ((cp == 42)) {
this.Advance(s, ref cp, ref len, false);
goto q1;
}
goto errorout;
q1:
// [\/]
if ((cp == 47)) {
this.Advance(s, ref cp, ref len, false);
goto q2;
}
goto errorout;
q2:
return FAMatch.Create(0, s.Slice(position, len).ToString(), position, line, column);
errorout:
if ((cp == -1)) {
return FAMatch.Create(-1, s.Slice(position, len).ToString(), position, line, column);
}
this.Advance(s, ref cp, ref len, false);
goto q0;
}
private FAMatch NextMatchImpl(ReadOnlySpan s) {
int ch;
int len;
int p;
int l;
int c;
ch = -1;
len = 0;
if ((this.position == -1)) {
this.position = 0;
}
p = this.position;
l = this.line;
c = this.column;
this.Advance(s, ref ch, ref len, true);
// q0:
// [\/]
if ((ch == 47)) {
this.Advance(s, ref ch, ref len, false);
goto q1;
}
goto errorout;
q1:
// [\*]
if ((ch == 42)) {
this.Advance(s, ref ch, ref len, false);
goto q2;
}
goto errorout;
q2:
return _BlockEnd0(s, ch, len, p, l, c);
errorout:
if (((ch == -1)
|| (ch == 47))) {
if ((len == 0)) {
return FAMatch.Create(-2, null, 0, 0, 0);
}
return FAMatch.Create(-1, s.Slice(p, len).ToString(), p, l, c);
}
this.Advance(s, ref ch, ref len, false);
goto errorout;
}Main thing that makes it tough is the use of UTF-32 codepoints instead of chars - neces
Quote:
I actually did dotNetPeek them
In my experience, I have found peeking and looking at the actual source code is not always the same thing. The compiler tends to optimise and rewrite code these days...
Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
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Quote:
I actually did dotNetPeek them
In my experience, I have found peeking and looking at the actual source code is not always the same thing. The compiler tends to optimise and rewrite code these days...
Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
In that case I wasn't as interested in the source code as I was in the final code. I was looking for optimization opportunities, and I was looking at the IL as well and comparing it to mine.
Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
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It's not 20ms. it's a 30% improvement in overall execution time. If I increase the test size to run for 90 seconds, it would run for about 60 after the optimization. If you get even 20% off the execution in critical code paths it's generally worth the optimization. I mean, of course it depends on the circumstances, and is less true of business development, or development with large teams or teams with with a lot of turnover, where you can't afford the additional maintenance overhead, limited knowledge transferability and cognitive load of optimized code. That is not a microoptimization. 30% off total execution time is a significant savings. Adding, I used to use garbage collection in my ISAPI applications because it prevented nasty heap fragmentation due to all the string processing required of web servers. It made things faster. GC isn't always a losing performance proposition. When the situation calls for it, it can increase overall performance.
Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix
30% in overall execution time? Does your code consist mostly of enumerations and while loops? No, it doesn't go from 90 to 60, unless all your code is enumerate. Real world code is more than just retrieving a list. Sorry Honey. VS shows you the place where it spends most time. "Limited knowledge trans...", aight, you're allowed to your views, I have mine. And yes, mucking about a for loop vs enumerable in an VB6 runtime (which .NET IS) is not even a microoptimization, it is purely whining. Write in a goddamn real language if it is that important an link to it from .NET where you need it. You have fallen, my angel, and very deep. Time critical stuff isn't worth .NET, and it isn't worth my time to read about 20 ms savings in a different loop that is less readable. When the situation calls for it, you want someone who works with pointers, not with .NET. I would write a library for you to link to that does the heavy lifting, "if the situation calls for it". Because .NET is just an evolution of VB6, it is just a runtime interpreting with a memory manager. It is vbruntime600 with additional libraries. Any compiled language with pointers laughs out loud. This is not even an argument honey. EVERYONE can use a profiler and see how much your micro optimization may help them. If it does, then yay for them for writing ineffcient code. My code does not consist of merely enumerations, it deals with a lot more stuff. Real world code consist of more than "looping". And if speed is that paramount then why are you using .NET? Are you really blabbing about how to do a for loop in a VB-variant? That is what C# is, VB6 in a new interface, but that translates 1 on 1 to VB. You really whining about the performance of BASIC code (by any other syntax, but still a rose/VB)? And you prove it by throwing some unreadable code, that saves me 20 ms? That is going to impress, really. You will shave of some ms, sacrificing readability for some code that takes more than 2 secs? Did you know that humans only see 48 frames per second? The END USER will not even notice, but the manager that pays someone to update your code WILL. You're gonna go far kid.
Bastard Programmer from Hell :suss: "If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.
