Zen++

Zen++ Devlog VI

This was a pretty big update but I didn’t add anything that is syntaxically weird. I added functions, vectors, and strings.

What changed:

1. Functions + Returns

   • Added parsing/eval support for fn name(args){...} and return expr.
   • Added scope
   • Added built-in functions like read() and print()

2. Strings

   • Strings are defined with "string"
   • Can store/print/concatenate strings.
   • You can index into strings (s[i]) and use len(s).

3. Vectors (Dynamic Arrays)

   • Added vector syntax: [1, 2, 3].
   • Added vector indexing: v[i].
   • Added built-ins:
     • len(v)
     • push(v, x)
     • pop(v)
   • Added vector concatenation

4. Multidimensional vectors

   • Because vectors can contain vectors, nested structures like [[1,2],[3,4]] just work.
   • Nested indexing works (m[1][0]).

5. Comments + Illegal Character Throwing

   • Added support for comments like // or /* ... */
   • Added stricter behavior for unknown/invalid characters so bad input doesn’t silently pass.

6. Reorganization

   • src/ has source code
   • test/ has tests
   • build/ now contains the compiled binaries
   • docs/ contains docs/devlogs.

7. Makefile + Testing

   • Added a Makefile with nice commands
   • make run launches REPL.
   • make run <file.zpp> runs a file directly.
   • Made test.zpp as a file with every command in the language and then wrote the expected output and made make test run the test script and compare output.

Changelog

• functions and vectors
• multi line buffer

Zen++ Devlog V

Ok so in this devlog I spent a lot of time thinking about syntax and I would like some feedback about for loops.
First though, while loops were simple (not simple to implement these loops cooked me in coding but syntaxically simple), its just.

while boolean {
do this code here yeah
}

So while loops are very simple. Now for loops were a pain. I wanted them to be simple as this is meant to be super fast to write for competitive programming and the likes. So for this I took inspiration from my C++ template file.

#define FOR(i, a) for(int i = 0; i < a; i++)
#define ROF(i, a) for(int i = a; i >= 0; i--)
#define FORA(i, a, b) for(int i = a; i <= b; i++)
#define ROFA(i, a, b) for(int i = a; i >= b; i--)

That’s how I macro for loops during Codeforces contests. So instead of
for(int i=0;i<n;i++){...} I can just do FOR(i,n). Now I wanted something nice and simple for Zen++ to. So I landed on this:
A four loop has four components, the variable used, the start, the end, and the step. So why not instead of writing those as a declaration, a boolean, and an incrementation like in C++, just treat those almost as paramateres to a method. So thats what I did.
for i start end step {...}
Thats the syntax. If you want a reverse for loop you just make end bigger than start and step will be negative.
There is a 3-arg version which defaults step to 1 or -1 depending on direction and looks like: for i start end{...} and there is a 2-arg one which is: for i end{...} and defaults step to +1 and start to 0. So for codeforces you can just write for i n{...}. Very simple, but leave comments if you think its ugly. Its exclusive by default rn with no way to make it inclusive, I’ll fix that later.

Changelog

• for and while loops

Zen++ Devlog IV

I added if else statments to the code! The way an if else-if else statment will be written is like tihs:

if bool1{
    x=1
}else if bool2{
    x=2
}else{
    x=3
}

Note the lack of parantehsis, you don’t rly need them beacuse you know your condition is just gonna be sandwiched between the if and the next curly brace. Also now that I added braces I made the parser handle the braces and the AST handle blocks of code.

What changed:

1. The lexer recognizes if, else, { and }.
2. The parser builds block nodes and full if/else chains, and parses the full program instead of a single statement.
3. The evaluator now runs blocks and if/else nodes.
4. The REPL buffers lines and runs the program when you submit a blank line.

Changelog

• If / Else Statments + Blocks

Zen++ Devlog II

I added variables and assignment. You can declare a variable like x=4 and reassign it like x=5

What changed:

1. The lexer now recognizes identifiers and the = token
2. The AST supports variable nodes and assignment nodes.
3. The parser now uses a lookahead to treat identifier = expr as an assignment, and it also lets identifiers show up inside normal expressions.
4. The evaluator keeps a small variable map so assignments store values and identifiers read them back.

Changelog

• Variables and Assignment
• devlogs