Otherwise the function List.Generate returns an error. The new values must have the same type on each of iteration including the first value. The third parameter is a function that describes how to generate new values of List. While a function returns ‘True’ the calculation will continue.

This function must return ‘True’ or ‘False’ value. The second parameter is a condition of interrupting calculation. The first parameter is a function that returns the first value of list. We will describe here the required parameters only. The function takes 3 required parameters and 1 optional parameter. Optional selector as nullable function ) as list Loop in M language can be implemented using the List.Generate function. The condition of interrupting is a function, too. We can call the special function that is being called by M engine while special interrupting condition has ‘ True’ value. How can we create loops in M Language in this case?įortunately, we have the following construction in M Language. The above means we do not have loops as we know them from imperative languages like C# or PHP. Herewith the results of calculations do not store in memory and M Language does not use a stack like imperative languages do it. So if you write a program in M Language you need to create a sequence of functions which call each other one by one to transform your data as you want. Functions can return a value, list, table etc as result. Any function can take a result of calling of other function as parameter.

It means any action you do on a data is a function. The first thing we need to say is M Language is functional language. The code above is the loop which calculates sinus of angle from 0 to 2π with step 0.01 radian.

For loop in r language example