# ChaiScript Overview

ChaiScript is an embedded scripting language designed for C++. You can use ChaiScript to expand the functionality of RealmJoin. Use the following script examples and the scripts in the [GK Script Objects](/script/reference.md) section to learn how to customize your RealMigrator.

To download ChaiScript click the following link: <http://chaiscript.com>

## Variables

```c++
var i; // uninitialized variable, can take any value on first assignment;

var k = 5; // initialized to 5 (integer)
var &m = k; // reference to k
```

## Built in Types

```c++
var i = 1; // creates an integer
var u = 1u; // creates an unsigned integer
var s = "hello"; // create a string
var f = 1.0; // creates a float

var v = [1,2,3u,4ll,"16", `+`]; // creates vector of heterogenous values
var m = ["a":1, "b":2]; // map of string:value pairs
```

### Working with strings

```shell
chaiCmd.exe
eval> var s="Hello";            // Assignment
Hello
eval> s+= " World !!";          // Concatenation
Hello World !!
eval> s.size();                 // Size
14
eval> s.find("World");          // Find
6
eval> s[6];                     // reference character
W
eval> s.substr(0, 6);           // Substrings
Hello
eval> s.substr(6,-1);
World !!
eval> s.find("o");              // Find - reverse find
4
eval> s.rfind("o");
7
```

## Conditionals

```c++
if (expression) { }

if (expression) { }
else { }

```

## Loops

```c++
// c-style for loops
for (var i = 0; i < 100; ++i) { print(i); }
```

```c++
// while
while (some_condition()) { /* do something */ }
```

```c++
// ranged for
for (x : [1,2,3]) { print(x); }
```

Each of the loop styles can be broken using the break statement. For example:

```
while (some_condition()) {
  /* do something */
  if (another_condition()) { break; }
}
```

## Functions

```c++
def myfun(x, y) { x + y; } // last statement in body is the return value
def myfun(x, y) { return x + y; } // equiv
```

### Optionally Typed

```c++
def myfun(x, int y) { x + y; } // requires y to be an int
```

## Classes/Objects

### Class definition

```c++
class MyType {
  var value;

  def MyType() {
    this.value = "a";
  }

  def get_value() {
    "Value Is: " + this.value;
  }
};
```

### Working with class objects

```c++
var m = MyType(); // calls constructor
print(m.get_value()); // prints "Value Is: a"
m.value += " joke";
print(m.get_value()); // prints "Value Is: a joke"
```

## JSON

| Script      | Function                                                                                                                           |
| ----------- | ---------------------------------------------------------------------------------------------------------------------------------- |
| `from_json` | Converts a JSON string into its strongly typed (map, vector, int, double, string) representations                                  |
| `to_json`   | Converts a ChaiScript object (either a object or one of map, vector, int, double, string) tree into its JSON string representation |


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.realmigrator.com/script/chaiscript.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.