Final-year Computer Science project

TongaLang

An educational interpreted programming language using Tonga-based keywords and a desktop IDE.

Active development2025–2026Public repository

Verified project evidence from the current implementation.

Role: Developer & Researcher
Status: Active development
Year: 2025–2026
Stack: Python · PLY · Tkinter · Pytest · PyInstaller · .tg files

01 · Context

The problem

Beginner programmers may need to learn programming concepts and interpret unfamiliar English syntax at the same time, adding linguistic and cognitive load.

The response

TongaLang combines Tonga-derived vocabulary with a small interpreted language and a guided desktop workspace. Learners see concepts in context, receive a plain-language recovery step when code is wrong, and stay in control of every suggested edit. It remains an educational language rather than a replacement for mainstream production tools.

02 · Contribution

What I built

01
Researched minimal languages and interpreter construction, then mapped core programming concepts into Tonga-derived vocabulary through linguistic research and native-speaker consultation.
02
Built the lexer, parser, abstract syntax tree, interpreter, runtime environment and native functions before separating the language engine from its Tkinter IDE.
03
Designed a pure diagnostics model with stable codes, exact source spans, bilingual explanations and guarded edits that never execute or silently rewrite learner code.
04
Added debounced live analysis and a collapsible Problems workflow with precise highlighting, Go to Code, Copy Details and undoable Apply Fix actions.
05
Reworked graphical input around one thread-safe shared dock so bala() pauses only the interpreter, keeps the interface responsive and echoes submitted values into Output.
06
Expanded navigation, semantic syntax colours, scrolling, safety settings, project guidance, automated contracts and privacy-reviewed publication evidence.

03 · Implemented evidence

Current
capabilities.

Custom lexer, parser, AST and interpreter

Variables, arithmetic, Boolean logic, conditions, loops, functions and scope

Side-effect-free lexical, syntax and semantic diagnostics

Bilingual error codes, exact source highlighting and guarded Apply Fix actions

Shared Problems/Program Input dock across Editor and Output

Responsive bala() pause and resume with a visible input transcript

Semantic colours for eight reserved-word groups in dark and light themes

Back and Forward history plus a collapsible navigation menu

Scrollable grouped Settings and structured About guide

AST explorer, internal console and execution safety limits

17 packaged .tg example programs

179 automated regression, adversarial and GUI integration tests

Product evidence

See the work
in context.

Current, privacy-reviewed captures from the implemented product.

A silent, captioned walkthrough from semantic editing and Apply Fix through bala() input, scrolling and the structured About guide.

TongaLang Problems dock explaining an unnecessary semicolon and offering a guarded Apply Fix action — Problems translates a precise source error into bilingual guidance and offers an edit only when the correction is deterministic.

TongaLang Output view with the shared Program Input dock waiting for a bala value — bala() keeps Output visible, opens one focused input surface and records the submitted value in the program transcript.

Scrollable TongaLang Settings showing grouped execution controls and semantic syntax colours — Scrollable, collapsible settings expose safety limits, language tools and accessible colours without clipping at smaller window sizes.

Structured TongaLang About screen with author, academic and project information — The project guide explains the author, academic context, purpose, architecture, quick start, features and current safety scope.

TongaLang graphical abstract syntax tree with source-linked nodes — The AST explorer connects executable structure back to the learner's source code.

TongaLang Test Lab showing all checks passing — The Test Lab turns regression results, weakness probes and coverage into visible evidence.

Execution pipeline

From source to
feedback.

Source .tg program
Lexer tokens
Parser grammar
AST structure
Interpreter runtime
Output or guided problem

04 · Engineering

Hard parts,
clear decisions.

Helpful fixes without unsafe guessing

The IDE needed broad recovery advice while editing only deterministic mistakes. Suggested edits therefore carry the expected original text, reject stale source and leave ambiguous choices to the learner.

Input without freezing the IDE

bala() must pause execution, not navigation or scrolling. A worker-thread input provider and single-use queue handoff keep Tkinter responsive and prevent repeated submissions.

One dock across changing views

Problems and Program Input share state, expansion and sash size while Editor and Output change underneath them. Runtime failures, successful runs, pending input and manual inspection each require a distinct transition.

Growing without regressions

Diagnostics, tokens, grammar, runtime behaviour, highlighting and existing programs affect one another, so changes are protected by error-contract, adversarial and GUI integration tests.

05 · Reflection

What I learned

Planned or still in development

Add progressive beginner lessons, expected output and resettable examples
Add keyword and native-function autocomplete with short contextual help
Add a variable inspector and simple step-through execution
Persist settings, dock sizes, recent files and safe session recovery
Arrange a Tonga educator review and formal Narrator or NVDA accessibility testing
Add CI, version consistency checks and packaged Windows release artifacts

Public repository verified on 9 August 2026 at merged commit 93ba1f4: 17 runnable TongaLang examples and 179 passing automated tests. Publication media was checked at 1600×900; the silent H.264 demo is 1280×720, 30 fps, 52.03 seconds and 4.15 MB.

Project access

Inspect the source.

GitHub source

TongaLang