Decision Fundamentals¶
Sockets¶
Sockets contain data of a pre-determined type (essentially data types):
- Execution
These kinds of sockets don’t hold data, but they determine what actions occur when they are activated. If an input execution socket is activated, the node’s action is performed. If an output execution socket is activated, it passes the execution of the program to the connected input execution socket.
- Integer
These sockets hold integer (whole number) values.
- Float
These sockets hold floating-point values.
- String
These sockets hold strings, essentially an array of characters.
- Boolean
These sockets hold true (1) or false (0) values.
Note
The following data types have not been implemented yet. But they will be. Soon. Maybe.
- Collection
These sockets hold a collection of data.
- Programmer-defined Structure
These sockets hold defined structures of data.
- Programmer-defined Class
These sockets hold objects instantiated from classes.
Note
Integers, floats, and booleans are passed from socket-to-socket by value, whereas strings, collections, structures and classes are passed from socket-to-socket by reference. This is because of the way these values are represented in memory.
Wires¶
Wires connect 2 sockets together. The sockets they connect must be of the same data type, however. Wires allow data to be transferred between nodes, allowing you to take whatever output you want and feed it into the input of your choice.
An alternative to wires (if you know an input is always going to be the same value) are literals, which is data (that is the same data type as the input socket) that the socket uses instead of getting the value from a wire.
Wires are analogous to local variables in most common programming languages.
Nodes¶
Nodes are the building blocks of the Decision language. They dictate what happens when they are activated, and what calculations happen. They are analogous to statements in most common programming languages.
All nodes have inputs and outputs in the form of sockets. What the node does with the inputs and what it outputs depends on the node.
Execution nodes¶
Execution nodes are nodes that have at least one execution socket. These nodes perform an action once their primary input execution socket has been activated. Once that action is done, the node will then activate it’s primary output execution socket to pass the execution of the program to the next execution node.
Definition nodes¶
Definition nodes are execution nodes that do not have any input sockets. These nodes are therefore the start of a path of execution. Essentially, they define what functions do.
Non-execution nodes¶
Non-execution nodes have no execution sockets. These nodes perform a calculation on their inputs without affecting the state of the program. These nodes are used to manipulate values before they are fed into execution nodes.
Sheets¶
Every Decision source file represents a sheet. Sheets are essentially a collection of nodes, wires and properties. (The fact that they are a collection of nodes and wires means you can model sheets as directed graphs, for you mathematicians out there)
Properties¶
Properties aren’t necessarily stored in sheets, but they manipulate the sheet’s metadata to provide extra information, or to specify something about the sheet. For example:
Properties can define global variables that nodes can get and set the value of.
Properties can define functions/subroutines, and what their inputs and outputs are.
Properties can be used to import other sheets, which allows you to use other people’s programs or libraries for your convenience.