Furnica

The ant sits on a table of letters. The student writes a program with simple commands — UP, DOWN, LEFT, RIGHT, loops, conditions, and procedures — and the ant runs it step by step, pushing the letters out of its way. The goal: arrange the letters into a word. Furnica 3 is a Rust rewrite of the original “Furnica” program (Ant v2.00, 1999), and old .ant files open and run unchanged. Furnica is Romanian for “ant”.

Download Furnica · Program website · Source code on GitHub

Download and install¶

On the Releases page, pick the right file:

• Windows: the .msi installer adds Furnica to the Start menu, and .ant files open with a double click. The .zip needs no installation: unzip it and run Furnica.exe.
• macOS: open the .dmg and drag Furnica.app onto Applications. The app is not signed with an Apple certificate, so on first launch: right click → Open (on macOS 15+: System Settings → Privacy & Security → Open Anyway).
• Linux: sudo apt install ./furnica-*.deb or chmod +x furnica-*.AppImage && ./furnica-*.AppImage.

The language¶

Conditions: BORDER (the ant is facing the edge of the table) and NOT_BORDER. The ant faces the direction it last moved in.

The ant cannot leave the table, cannot push a letter over the edge, and cannot push two letters in a row. In any of these cases the program stops with an error, and the spot is marked in red on the table.

First program¶

The ant starts in the top-left corner, and the letter A is in column 4, row 3. The program takes the ant above the letter, then pushes the letter down:

// My first program: the ant pushes the letter A
BEGIN
REPEAT 3 TIMES
    RIGHT
END REPEAT
REPEAT 4 TIMES
    DOWN
END REPEAT
END

Procedures and conditional loops¶

The “Margini” (Borders) example walks around the whole table, whatever its size: each procedure goes in one direction until it reaches the edge. Here it is in Romanian, as it ships with the program:

PROCEDURA jos_pina_la_margine
    JOS
    CÎT NU_E_MARGINE EXECUTĂ
        JOS
    SFÎRȘIT CÎT
SFÎRȘIT PROCEDURA

PROCEDURA dreapta_pina_la_margine
    DREAPTA
    CÎT NU_E_MARGINE EXECUTĂ
        DREAPTA
    SFÎRȘIT CÎT
SFÎRȘIT PROCEDURA

// … the same for up and left

ÎNCEPUT
jos_pina_la_margine
dreapta_pina_la_margine
sus_pina_la_margine
stinga_pina_la_margine
SFÎRȘIT

Keywords in three languages¶

They can be written in any of the languages, with or without diacritics (INCEPUT, SFIRSIT, STINGA work just the same).

Editing the table¶

• The ant is moved by dragging it with the mouse, and a click rotates it.
• Letters are typed on the keyboard, like text: click a cell and type, the cursor moves to the next cell on its own.
• Letters are moved by dragging; dragged off the table (or right-clicked) they are deleted.
• The table can be anywhere from 3 × 3 to 20 × 20 cells.
• After a run, the starting table stays unchanged; Keep result turns the resulting table into the new starting table.

Code analyzer¶

The program is checked on every change, and the analyzer finds all the mistakes, not just the first one:

• misspelled words get a wavy underline (red = error, yellow = warning); hovering shows the explanation;
• the Problems list below the editor shows every error, and a click takes the cursor to the word;
• misspelled words get a suggested fix (“Did you mean RIGHT?”) that the Fix button applies;
• a program with errors won't run; warnings (unused procedures, empty blocks, WHILE loops that don't move the ant) don't block it.

Keyboard shortcuts¶

What's new compared to the original¶