I got my hands dirty while reading the book "Writing an interpreter in Go".

And then I'm done with "Writing a Compiler in Go". I think it would be great to have more illustrations about the concepts and the layout of the instructions and the stack.

• Lexer that distills the meaning of human readable source code into more essential form that arranges tokens which are defined and given its own meaning in the programming language.
• Parser that transforms source codes(tokens lexed by Lexer) to AST structure. Here, Top down operator precedence parser (a.k.a. Pratt parser) is picked up and implemented.
• AST (Abstract Syntax Tree)
• Interpreter that traverses the AST and evaluates (executes) it on the fly.
• Compiler that traverses the AST and generates the corresponding bytecode containing instructions, each instruction is made up of a opcode and one or two operands, or no operands at all. Jump instruction to implement conditionals.
• Stack based virtual machine that executes the bytecode and do stack arithmetic and so forth using a stack. Keeping track of variable bindings, global or local ones (variable scopes). Call stack and frame to execute function call and manage stuff around it such as arguments to the function call and the function's local variables, the return address where the execution flow will get back after the currently executing function finishes.
• Closure, free variable. Recursive funcition call, function that calls itself inside it.