Function codegen

docs/app/js/sanddance-app.js:144494–144558

(opt)

    return n && (s[0] === '"' && s[n] === '"' || s[0] === "'" && s[n] === "'") ? s.slice(1, -1) : s;
}
function codegen(opt) {
    opt = opt || {};
    const allowed = opt.allowed ? (0, _vegaUtil.toSet)(opt.allowed) : {}, forbidden = opt.forbidden ? (0, _vegaUtil.toSet)(opt.forbidden) : {}, constants = opt.constants || Constants, functions = (opt.functions || Functions)(visit), globalvar = opt.globalvar, fieldvar = opt.fieldvar, outputGlobal = (0, _vegaUtil.isFunction)(globalvar) ? globalvar : (id)=>`${globalvar}["${id}"]`;
    let globals = {}, fields = {}, memberDepth = 0;
    function visit(ast) {
        if ((0, _vegaUtil.isString)(ast)) return ast;
        const generator = Generators[ast.type];
        if (generator == null) (0, _vegaUtil.error)("Unsupported type: " + ast.type);
        return generator(ast);
    }
    const Generators = {
        Literal: (n)=>n.raw,
        Identifier: (n)=>{
            const id = n.name;
            if (memberDepth > 0) return id;
            else if ((0, _vegaUtil.hasOwnProperty)(forbidden, id)) return (0, _vegaUtil.error)("Illegal identifier: " + id);
            else if ((0, _vegaUtil.hasOwnProperty)(constants, id)) return constants[id];
            else if ((0, _vegaUtil.hasOwnProperty)(allowed, id)) return id;
            else {
                globals[id] = 1;
                return outputGlobal(id);
            }
        },
        MemberExpression: (n)=>{
            const d = !n.computed, o = visit(n.object);
            if (d) memberDepth += 1;
            const p = visit(n.property);
            if (o === fieldvar) // strip quotes to sanitize field name (#1653)
            fields[stripQuotes(p)] = 1;
            if (d) memberDepth -= 1;
            return o + (d ? "." + p : "[" + p + "]");
        },
        CallExpression: (n)=>{
            if (n.callee.type !== "Identifier") (0, _vegaUtil.error)("Illegal callee type: " + n.callee.type);
            const callee = n.callee.name, args = n.arguments, fn = (0, _vegaUtil.hasOwnProperty)(functions, callee) && functions[callee];
            if (!fn) (0, _vegaUtil.error)("Unrecognized function: " + callee);
            return (0, _vegaUtil.isFunction)(fn) ? fn(args) : fn + "(" + args.map(visit).join(",") + ")";
        },
        ArrayExpression: (n)=>"[" + n.elements.map(visit).join(",") + "]",
        BinaryExpression: (n)=>"(" + visit(n.left) + " " + n.operator + " " + visit(n.right) + ")",
        UnaryExpression: (n)=>"(" + n.operator + visit(n.argument) + ")",
        ConditionalExpression: (n)=>"(" + visit(n.test) + "?" + visit(n.consequent) + ":" + visit(n.alternate) + ")",
        LogicalExpression: (n)=>"(" + visit(n.left) + n.operator + visit(n.right) + ")",
        ObjectExpression: (n)=>"{" + n.properties.map(visit).join(",") + "}",
        Property: (n)=>{
            memberDepth += 1;
            const k = visit(n.key);
            memberDepth -= 1;
            return k + ":" + visit(n.value);
        }
    };
    function codegen2(ast) {
        const result = {
            code: visit(ast),
            globals: Object.keys(globals),
            fields: Object.keys(fields)
        };
        globals = {};