Neko BASIC

A simple BASIC interpreter and REPL written in C.

Features

• REPL Interface: Interactive environment for writing and running BASIC programs.
• Memory Management: Configurable memory pool for program and variable storage.
• BASIC Dialect: Supports a variety of standard BASIC keywords and functions.
• Cross-Platform: Built with CMake, supporting both Linux and Windows.

Supported Keywords

Statements

PRINT, LET, IF, THEN, ELSE, GOTO, GOSUB, RETURN, FOR, TO, STEP, NEXT, WHILE, WEND, INPUT, DIM, END, STOP, REM

Graphics

SCREEN, CIRCLE, LINE, RECT, COLOR, CLEAR, FLIP, POINT, TEXT, SPRITE, FILLED, CLOSE, POLL

• Sprites: SPRITE LOAD id, "file", SPRITE DRAW id, x, y [, scale], SPRITE FREE id
• Input: POLL MOUSE xvar, yvar [, bvar], POLL KEY kvar

Commands

LIST, RUN, NEW, LOAD, SAVE

Functions & Operators

• Arithmetic: +, -, *, /, ^, MOD
• Logical: AND, OR, NOT
• Comparison: =, <>, <, >, <=, >=
• Mathematical: SQR, INT, ABS, RND, SIN, COS, TAN, LOG, EXP, ATN, SGN
• Strings: LEN, MID$, LEFT$, RIGHT$, STR$, VAL, CHR$, ASC

Building

Prerequisites

• C compiler (supporting C23)
• CMake 4.0 or higher

Build Instructions

mkdir build
cd build
cmake .. # Add -DNEKO_BASIC_GRAPHICS=OFF to disable graphics
cmake --build .

Usage

Run the executable to start the REPL:

./neko_basic

Command Line Arguments

• -m, --mem <size>: Specify the memory pool size in MiB. If not provided, the program will prompt for it on startup.

Example Program

10 PRINT "Hello, Neko BASIC!"
20 FOR I = 1 TO 5
30   PRINT "Iteration: "; I
40 NEXT I
50 END

License

This project is licensed under the MIT License - see the LICENSE file for details.