Vitro / pantsman

What is Vitro?

Vitro is a lightweight programming language that supports basic arithmetic, variables, and control structures.

Arithmetic Operations

• Supports addition (+), subtraction (-), multiplication (*), division (/), and exponentiation (^).
• Parentheses () can be used to specify precedence.

Variables

• Identifiers start with a lowercase letter and can include alphanumeric characters.
• Assignment is done using x = 10; syntax.

Expressions and Processes

• Distinguishes between Expr and Process.
• Process can include literals, variables, parenthesized expressions, and if expressions.

Conditional Expressions

• Supports if <Expr> <CompareOp> <Expr> then <Process> else <Process>.
• Comparison operators include ==, !=, <, <=, >, >=.
• Both then and else clauses are mandatory.

Return Values

• return <Process>; is used to produce the program's result.

Syntax Flexibility

• Whitespace and line breaks are ignored for readability.
• Statements are separated by semicolons ;.

AST and Evaluation

• Generates an Abstract Syntax Tree (AST) for evaluation.
• eval function executes calculations while maintaining variable environment.

Install

Download from https://github.com/pantsman-jp/Vitro.

Usage

Require GHCup. I use ghcup 0.1.50.2, ghc 9.6.7, cabal 3.12.1.0.

To run:

% cabal run

Then you can input a program, and it is evaluated. Like this:

>
x=1; y=0; return if x==y then 1 else 0;

output is of course...

0

Note

There is a line break after > . It's not a fatal bug. I will fix it when I feel like it.

License

Copyright © 2025 pantsman