On 29 Mar 2020, at 14:35, Wolfgang Schuster <wolfgang.schuster.lists@gmail.com> wrote:

Gerben Wierda schrieb am 29.03.2020 um 14:30:

On 29 Mar 2020, at 12:58, Wolfgang Schuster <wolfgang.schuster.lists@gmail.com> wrote:

Gerben Wierda schrieb am 29.03.2020 um 12:52:

I am using MetaFun (Lua code) to create METAPOST commands from an XML file. One of the issues I am running into that in METAPOST I have to handle strings with " characters in them and METAPOST doesn’t like those. The argument using the string
Foo "Bar” Foo

    ^^^

Use correct left quotation marks or \quotation{…}.

I’m not hard coding the string, I’m reading it from an XML. So, whatever I do, I need to do it by manipulating the string.
E.g. if the string I read contains
Foo "Bar” Foo
your suggestion means  I have to programmatically change that to
Foo \quotation{Bar} Foo
which is too complicated, given that I don’t have regular expression replace at my disposal.
I might be able to change al “ instances into something else by walking through the string and building a new one.

Your example uses " before Bar and not “ which is the problem.