search_provider.js

const Cinnamon = imports.gi.Cinnamon;
const St = imports.gi.St;

function perform_search(pattern){
    /* Test for numbers and operators and make sure it does not end with
       an operator, as that is not a valid operation */
    if (/^[0-9.+*/()-]+[0-9\)]$/.test(pattern)) {
        let solution = 0;
        try {
            solution = eval(pattern);
        }catch(err){}

        let awns = (Math.round(solution * 10000) / 10000).toString();
        if (awns != pattern) {
            let default_icon_app = Cinnamon.AppSystem.get_default().lookup_app("org.gnome.Calculator.desktop");
            let result = {
                id: awns,
                label: _("Solution: %s").format(awns),
                icon_app: default_icon_app
            };
            send_results([result]);
        }
    }
}

function on_result_selected (result) {
    let awns = result.id;
    copy_to_clipboard(awns);
}

function copy_to_clipboard (str) {
    let clipboard = St.Clipboard.get_default()
    clipboard.set_text(St.ClipboardType.CLIPBOARD, str);
}