The syntax ambiguity to which Crockford refers is that if an open curly brace is not found on expression context, it will be recognized like a block, and not like the start of an object literal. For example: {“foo”: “bar”} // SyntaxError Will give you a syntax error, because it will be interpreted as a … Read more
Short answer: No. If it’s in the global scope, it’s available to anything. Long answer: if you’re eval()ing untrusted code that really wants to read or mess with your execution environment, you’re screwed. But if you own and trust all code being executed, including that being eval()ed, you can fake it by overriding the execution … Read more
You could split the path and reduce the path by walking the given object. If no Object exist, create a new property with the name, or an array. Later assign the value. function setValue(object, path, value) { var way = path.replace(/\[/g, ‘.’).replace(/\]/g, ”).split(‘.’), last = way.pop(); way.reduce(function (o, k, i, kk) { return o[k] = … Read more
My standard answer to this question whenever it crops up: Don’t use eval (especially as you’re stating that this is user input) or reinvent the wheel by writing your own formula parser. Take a look at the evalMath class on PHPClasses. It should do everything that you’ve listed here. EDIT re: Unfortunately evalMath does not … Read more
C++ doesn’t have reflection so you must hack it, i. e.: #include <iostream> #include <map> #include <string> #include <functional> void foo() { std::cout << “foo()”; } void boo() { std::cout << “boo()”; } void too() { std::cout << “too()”; } void goo() { std::cout << “goo()”; } int main() { std::map<std::string, std::function<void()>> functions; functions[“foo”] = … Read more
For read-only controls they are the same. For 2 way databinding, using a datasource in which you want to update, insert, etc with declarative databinding, you’ll need to use Bind. Imagine for example a GridView with a ItemTemplate and EditItemTemplate. If you use Bind or Eval in the ItemTemplate, there will be no difference. If … Read more
arr$varEnvCol[$index]=”$(…)” doesn’t work the way you expect it to – you cannot assign to shell variables indirectly – via an expression that expands to the variable name – this way. Your attempted workaround with eval is also flawed – see below. tl;dr If you use bash 4.3 or above: declare -n targetArray=”arr$varEnvCol” targetArray[index]=$(echo $line | … Read more
Solution 1. Use CallByName. Option Explicit Private Type Callable o As Object p As String End Type Public Sub SetProperty(ByVal path As String, ByVal Value As Variant, Optional ByVal RootObject As Object = Nothing) With GetObjectFromPath(RootObject, path) If IsObject(Value) Then CallByName .o, .p, VbSet, Value Else CallByName .o, .p, VbLet, Value End If End With … Read more
ast.literal_eval() accepts + in the evaluated data because 5+2j (complex number*) are valid literals. The same applies to -. To keep the code simple, no attempt is made to exclude + or – as a binary operators. No other operators are allowed; the function is supposed to only accept literals, not expressions. In other words, … Read more
Your question leaves a lot of room for interpretation. I’m taking a guess you aren’t accustom to building a whole pipeline of lexing, parsing, maybe type checking, and evaluating. The long answer would involve you defining what language you wish to evaluate (Just integers with ‘+’, perhaps all rationals with ‘+’, ‘-‘ ‘*’, “https://stackoverflow.com/”, or … Read more