Can we refactor output-svg.scm to avoid regexp?

[K.L.]

Hello guys.

I ran a profiling for SVG backend engraving, I saw the most time cost
(95%+) is taken by regexp execution.

It seems the usage of regexps in output-svg.scm is to extract vector font
content fragments from font svg assets. Can we refactor this work by an XML
parser, maybe in C++?

I saw there is another alternate option, svg-woff. But I encountered the
scm error:

> output-svg.scm:448:16: Unbound variable: paper
>

It seems an unresolved old bug for some years after googling it.

This may be the biggest performance bottleneck of SVG backend at present,
once fixed, we will get huge improvement.

Any ideas?

[image: image.png]
[image: image.png]