Lists & loops

Lists are a way to collect elements into a single place. In Pikt, an empty list can be created by calling the listOf(items...) function:

Now this blue variable holds a list with zero elements. Additional initial elements can be passed as arguments.
In the following example the list contains a 0 and a 1:

Add/remove

New elements can be added later by calling the addToList(list, items...) function (keep in mind that the magenta pixel in the bottom left corner is a funcall ):

The inverse is given by removeFromList(list, items...) .

Get/set

The content of a list (or string) in a certain position can be accessed via the dot operator using the <list> dot <index> syntax, where index is a number, either directly used or stored in a variable.

The following example stores the first element of the list (index 0 ) to a variable :

On the other hand, here we set the first element (previously 0 ) to 1 :

See Accessing fields for further information about the dot operator.

Range

The range(start, end) function can be really handy, especially when working with for loops, as it generates a list of integers from start up to (or down to) end, both inclusive.
In this example start is 0 and end is 10, so that [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10] is generated.

For-each

For-each is the only type of loop supported by the language. Its syntax is:
foreach <list> <block>, where <block> is a block of code with an optional argument, that starts with lambda.open and ends with lambda.close .

The following piece of code prints each element of a list:

foreach <list> lambda.open <argument>
    print <argument>
lambda.close

Given that the list is the blue one from the Range example, this is is what the previous pseudocode looks like in Pikt:

The orange pixel is our argument, which goes from 0 to 10 (the contents of the list), and gets printed out.

Break

A break can be performed on loops by putting two return statements one next to another. This will exit the loop.
From the previous example:

This will print only the first element in the list before breaking the for-each loop. A break can be inserted inside nested blocks, such as if.