# Include and import

### Include and import declarations

The **include** declaration imports all types, functions and constants from the specified files and their included files.

The **import** declaration imports only public types, functions and constants from the specified files and their included files. Public objects are defined using the **pub** keyword.

```
stringConst         = "`" { unicode_char } "`" | stringDoubleConst
stringDoubleConst = `"` { unicode_char | uShort | uLong | escapedChar | byteVal } `"`
importDecl = "import" "{" {stringConst newline} "}"
includeDecl = "include" "{" {stringConst newline} "}"
```

Consider the visibility of objects as a table. Let there be two files.

```
// a.g can include or import b.g
func afunc(i int) : return i*2
pub func apubfunc(i int) : return i*3

// b.g 
func bfunc(i int) : return i*4
pub func bpubfunc(i int) : return i*5
```

Let the *c.g* file can import or include *a.g* file. You can see what functions are visible in *c.g* in different situations.

|          | <p>include a <br> a includes b</p> | <p>include a <br> a imports b</p> | <p>import a <br> a includes b</p> | <p>import a <br> a imports b</p> |
| -------- | ---------------------------------- | --------------------------------- | --------------------------------- | -------------------------------- |
| afunc    | visible                            | visible                           |                                   |                                  |
| apubfunc | visible                            | visible                           | visible                           | visible                          |
| bfunc    | visible                            |                                   |                                   |                                  |
| bpubfunc | visible                            |                                   | visible                           |                                  |

### Pub declaration

The **pub** declaration marks the next function, type or constants as public. They can be imported with **import** declaration.

```
pubDecl = "pub"
objects = [pubDecl] (structDecl | FnDecl | ConstDecl | FunctionDecl)
```

The **pub** keyword indicates that the next function, constants, or structure will be passed when the file is imported.

```
pub const IOTA {  // public constants. Visible when include or import
    MY1
    MY2
}

const IOTA*2 {  // private constants. Visible only when include
    MY3
    MY4
}
```