Hello, I've integrated muParser with Qucs-S. Now I'm back to the question of pulling technology parameters from "libs.tech/klayout/python/sg13g2_pycell_lib/sg13g2_tech.json". At first, my intention was to load the JSON file into a global structure separate from the component library: "extern QMapQString, QJsonObject PDK_TechParams;" where the QString would be the PDK name and the QJsonObject would contain all the variables in "sg13g2_tech.json". This QMap would be accessible at component level. I see that "sg13g2_tech.json" contains a lot of device specific constants, e.g.:

"rsil_model": "res_rsil",
        "rsil_rspec": "7.0",
        "rsilG2_model": "res_rsil",
... more rsil params        
        "rpnd_rspec": "339.0",
        "rpnd_rkspec": "14.0",
        "rpnd_rzspec": "4.6e-5",
... more rpnd params

I think it would be more convenient to append these variables inside the component definition in XML as "extra variables" (but make them read-only or even hidden). This would simplify the management of passing variables to muParser. These constants could be automatically appended/updated to the XML file by running a script (e.g. during PDK installation) that pulls data from "sg13g2_tech.json".. @Krzysztof Herman, do you see any problems with this approach?