General - EFS Functions

ICE Data Services -

General

 

Formula Concepts

 

  • Lifetime of a formula

 

A formula is created/instantiated/constructed when it is added to a chart. Upon being created, the preMain() function is called once for that formula and then the main() function is called for each available bar.. A formula is re-created (destructed and re-constructed) when the properties of the formula change (via the Edit Studies menu).

 

A formula is destroyed/destructed when the chart containing the formula is closed.

 

  • Lifetime of global variables

 

Global variables come to life the first time setGlobalValue() is called. The global variable will remain available in the global variable pool until removeGlobalValue() is called, or when the application is closed.

 

  • Formula Iteration.

 

The main() function is used to build individual bars. It is called once for each bar on a chart. Bars are iterated from right to left (or from the oldest to the newest bar). Everytime a tick occur, the main() function is called to iterate the most recent bar (most recent data).

 

Operators

 

Arithmetic

+  //plus

++  //increment

-  //minus

--  //decrement

*  //multiply

/  //divide

%  //modulus

 

String Operators

+  //concatenate

+=  //append

 

Logical Operators

&&  //AND

||  //OR

!  //NOT

 

Bitwise Operators

&  //Bitwise AND

^  //Bitwise XOR

|  //Bitwise OR

~  //Bitwise NOT

<<  //Bitwise LEFT SHIFT

>>  //Bitwise RIGHT SHIFT

 

Assignment Operators

=  //IS EQUAL TO

+=  //n = n + x;

-=  //n = n - x;

*=  //n = n * x;

/=  //n = n / x;

%=  //n = n % x;

&=  //n = n & x;

^=  //n = n ^ x;

|=  //n = n | x;

<<=  //n = n << x;

>>=  //n = n >> x;

 

Comparison Operators

==  //is Equal To

!=  //is Not Equal To

>  //is Greater Than

>=  //is Greater Than or Equal To

<  //is Less Than

<=  //is Less Than or Equal To

 

Reserved Words/Statements

 

break

comments

continue

dowhile

for

forin

function

ifelse

return

switch

var

while

with

 

See Also:

 

Ternary Operator