Re: Using incremental parsing in Emacs

[arthur miller]

Stefan Monnier <address@hidden> writes:

>> I see the buffer is fontified correctly. Does it parse the whole buffer?
>
> We have different levels of parsing.  At the bottom we have
> `syntax-ppss` (whose workhorse, implemented in C, is
> `parse-partial-sexp`) which only counts parentheses and looks for
> comment and string markers.  In the above case, `syntax-ppss` indeed
> parses the whole buffer, but given its limited scope this parsing is
> usually fast (it can be slow in some cases, because `parse-partial-sexp`
> is supplemented by `syntax-propertize-function` to handle the "unusual"
> cases of "strings/comments" (a typical example would be here-documents
> in shell scripts) and this is all implemented in Elisp using regexp
> searches).
>
> After this parsing is done, font-lock looks at the few lines actually
> displayed using its Elisp/regexps rules to apply the actual highlighting.
> This may look at more parts of the buffer, tho, depending on the actual
> font-lock rules.
>
>
>         Stefan

Thanks for the overview.
/a