Final-year Computer Science project

TongaLang

A beginner-focused interpreted programming language with Tonga-derived keywords, guided error recovery and an installable desktop IDE.

Completed2025–20263 project links

Verified project evidence from the current implementation.

Role: Developer & Researcher
Status: Completed
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. Version 0.2.0 can be installed directly on Windows, while documented source and native bundle paths support Linux. 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
Created the TongaLang visual identity and applied it consistently to the IDE window, executable, desktop shortcut and setup experience.
07
Built a reproducible Windows installer that installs per user, includes 17 examples and supports clean uninstallation without requiring administrator access.
08
Documented Linux source installation and native bundle creation, then published the checksum-verified v0.2.0 release with privacy-reviewed product 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, Grammar reference, internal console and execution safety limits

Windows installer, Start menu entry, desktop shortcut and uninstaller

Linux source installer and documented native bundle build

17 example .tg programs included with source and desktop installations

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 Setup selecting a per-user Windows installation folder — The Windows installer uses the TongaLang identity throughout, installs without administrator access and includes the example programs in the application directory.

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 — When bala() needs a value, TongaLang keeps Output visible, opens one focused input surface and pauses only the interpreter worker.

TongaLang Output showing a completed program and the value entered through Program Input — Submitted values are echoed into the authoritative Output transcript before execution continues, making interactive programs easier to follow and explain.

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 source editor using the light theme and semantic reserved-word colours — Dark and light editor themes give each reserved-word family a consistent semantic colour while preserving string and comment precedence.

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

TongaLang internal console showing project and runtime information — The internal Console provides a clear place to inspect IDE messages and runtime details without mixing them into learner program output.

TongaLang Grammar reference showing language rules and keyword examples — The built-in Grammar reference keeps language rules and examples close to the editor for learners who need a quick reminder.

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.

Packaging a complete learning environment

The desktop release needed more than a frozen executable. The build now carries the logo, runtime assets and examples into a per-user installer, documents reproducible builds and publishes a checksum for independent verification.

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 release CI, Windows code signing and distribution packages for major Linux formats

Public repository verified on 11 September 2026 at merged commit 956909b: TongaLang 0.2.0 includes 17 runnable examples and passes all 179 automated tests. The Windows installer is published with SHA-256 265e4a204bd56d9326b67c144f4fda966484b29bb8ea076a8c3292453b38f0ec. The silent H.264 walkthrough is 1280×720, 30 fps, 52.03 seconds and 4.15 MB.

Project access

Inspect the source.

Source code and documentation Download TongaLang 0.2.0 for Windows Windows and Linux installation guide

TongaLang