It details how the project itself works, not how to write code in it. If you would like to know how to write code in Spindle, please look at the user documentation!
With that out of the way, this document will lay out how Spindle works and will help you contribute to it.
The Lexer turns your list of tokens into something called an Abstract Syntax Tree (AST).
An AST is a tree-like data structure that represents the syntactic structure of source code written in a formal language, most commonly programming languages. It's a crucial intermediate representation used by compilers and interpreters to analyze, transform, and optimize code.
Key Characteristics of an AST:
Hierarchical Structure: An AST is a tree, meaning it has a root node and
branches that extend downward. Each node represents a specific syntactic
construct in the source code. Abstractness: Unlike a token list, an AST
doesn't represent every syntactic detail of the source code. It
focuses on the essential structure and meaning of the code, abstracting
away irrelevant details like parentheses and operator precedence.
The interpreter navigates this abstract syntax tree, actually running the
program. For example, the lexer just tells the interpreter there's a for
loop, how many times it needs to repeat, and the code inside of it to
repeat. But the Interpreter is actually what runs that for loop to produce a
result. Errors at this stage typically indicate a
critical language bug that needs to be
fixed immediately. Once it is finished, the interpreter will return the
result of the program. If the program runs successfully but does not
intentionally return anything, it returns null. This null value will get
filtered out by the shell.py file when it displays your result.