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High Level Constructs

unit

Table of Contents

 

Units and Functions

Units are groupings of functions and

also

variables appearing in .

mez files. They can be thought of as modules or namespaces. A

Mezzanine script

Helium app must have at least one unit.

Unit

The unit keyword must be followed

with

by a unique unit name.

Units are defined as follows

 A unit must have at least one function.

 

Info
  1. unit MyUnit;
  2. // Other code follows
  3.  
  4. string myVar;
  5.  
  6. int factorial(int x) {
  7.     if(x == 0 || x == 1) {
  8.         return 1;
  9.     } else if (x > 1) {
  10.         return factorial(x - 1);
  11.     }
  12.  
  13.     return 0;
  14. }
Status
colourBlue
titleHeads Up
 
Code Block
languagejava
titleUnit Example
linenumberstrue
unit MyUnit;
// Other code follows
 
string myVar;
 
int factorial(int x) {
    if(x == 0 || x == 1) {
        return 1;
    } else if (x > 1) {
        return factorial(x - 1);
    }
 
    return 0;
}

 

 

Info

Objects, enums and validators are global, so they can optionally be in a separate source code file without a unit.

 

Mez File Comments

Two types of comments are supported: single line comments and multi-line comments:

Single line comments

 

info
Code Block
languagejava
titleSingle Line Comments Example
linenumberstrue
//
 date tstamp = System
 date tstamp = System.now();

//
 decimal rand = System
 decimal rand = System.random();

 

And multi-line comments:

 

Info/* date tstamp = System
 Code Block
languagejava
titleMulti-line Comments Example
linenumberstrue
/* date tstamp = System.now();
decimal rand = System

decimal rand = System.random();
 
 */
 
 
 
 
 
This unit has one 
Variable and Function Scope
Suppose a unit MyUnit has a unit variable named myVar
. This variable has unit 
 and a function named factorial. Both have global scope and can be accessed by any function in this or other units, e.g. from TestUnit in the 
 unit. The unit also has a function named factorial. A unit must have at least one function
example below. The only time a variable or custom object in the Helium DSL is not globally scoped is when it is declared inside a function and thus scoped to the function alone. To refer to a unit’s member functions or variables from another unit, you have to use the scope operator 
 
 Info
  • unit TestUnit;
  •  
  • void test() {
  •     MyUnit:myVar = "New string value!";
    •     int f = 
    (the colon).
     Code Block
    languagejava
    linenumberstrue
    unit TestUnit;
void test() {
    MyUnit:myVar = "New string value!";
    int f = MyUnit:factorial(5);
    
}
     
     Note: Unit variables cannot be in line initialized when they are declared. The following code will not compile
     
     Info
    1. unit MyUnit;
    2.  
    3. string myVar = "some value"; // this is not a legal statement
     
    :
     Code Block
    languagejava
    linenumberstrue
    unit MyUnit;

string myVar = "some value"; // this is not a legal statement
     

     
    Additional Mentions and References
     
     Excerpt
    hiddentrue
    units | functions | comments | global scope