F# Feliz.viewengine benchmarks (slower?)

[jkone27]

• https://hamy.xyz/labs/2024-02_fsharp-html-dsl-long-page-benchmarks

• https://hamy.xyz/labs/2024-02_fsharp-html-dsl-deeply-nested-benchmarks

seems somehow Feliz is not as performant as Giraffe and Falco,
just wonder if there is simple improvements that could be made maybe with help of the community

in general as synthax Feliz.ViewEngine is just better than the other dsls in my view, more expressive and concise (i don't get sir hamy criticism there honestly), or at least is my favourite as empty lists passed around everywhere is not really smt i like or enjoy : )

[sporieg]

I ran the recursive html benchmarks locally and the worst performance hit in this case comes from the function getEscapeSequence

If I use the repo as is, the perf report is

Method	Mean	Error	StdDev	Gen0	Gen1	Gen2	Allocated
RunFalcoMarkup	1.166 ms	0.0225 ms	0.0309 ms	166.0156	166.0156	166.0156	2.38 MB
RunFelizViewEngine	4.633 ms	0.0913 ms	0.2005 ms	546.8750	492.1875	164.0625	9.01 MB

If I change the method

    let getEscapeSequence c =
        match c with
        | '<'  -> "&lt;"
        | '>'  -> "&gt;"
        | '\"' -> "&quot;"
        | '\'' -> "&apos;"
        | '&'  -> "&amp;"
        | ch -> ch.ToString()

    let escape str = String.collect getEscapeSequence str

to

let escape str  = System.Net.WebUtility.HtmlEncode str

I get:

Method	Mean	Error	StdDev	Gen0	Gen1	Gen2	Allocated
RunFalcoMarkup	1.094 ms	0.0214 ms	0.0189 ms	166.0156	166.0156	166.0156	2.38 MB
RunFelizViewEngine	2.088 ms	0.0241 ms	0.0226 ms	246.0938	242.1875	164.0625	3.6 MB

There are probably more improvements to find, its still slower but that is the lowest hanging fruit.

[dbrattli]

I have updated the library to be about 35-55% faster. But note that Feliz.ViewEngine is targeted for .NET and Fable so also works when transpiled to JS, TS and Python, so we cannot use System.Net. @sporieg Could you rerun the benchmarks with the latest release? I cannot find the sources of the benchmark.