CalcNova

Fast. Precise. Private. Everywhere.

Current product version: 2.9.7

CalcNova is a completed, open-source, privacy-first, cross-platform calculator built with C#, .NET, and Avalonia UI. It combines a project-owned expression engine with scientific, exact-rational, engineering-notation, programmer, Unicode, conversion, graphing, statistics, equation, matrix, date/time, currency, history, persistence, accessibility, localization, packaging, and release-validation capabilities while keeping ordinary calculations local.

Project status: Complete for version 2.9.7. Future repository changes may provide maintenance, compatibility updates, security fixes, translations, or optional enhancements; they are not required to complete the 2.9.7 product scope.

Status

Version 2.9.7

The public/product version is 2.9.7, the .NET/NuGet package version is 2.9.7, and the corresponding normalized release tag is v2.9.7. Android and iOS use numeric build code 20907. See docs/VERSIONING.md for the complete mapping.

The earlier 2.9.0, 2.9.5, and 2.9.6 checkpoints are preserved in docs/releases/2.9.0.md, docs/releases/2.9.5.md, and docs/releases/2.9.6.md. The repository then advanced to the current 2.9.7 maintenance baseline.

2.9-series release and platform maintenance

The 2.9 series adds release-consistency and cross-platform maintenance without removing the completed calculator feature set:

• centralized SDK-independent release identity parsing in tools/release_identity.py;
• fail-closed consistency checks for display, SemVer, package, assembly/file, informational, release-tag, and mobile-build identities;
• version-aware packaging, completion-status, platform-support, and release-document validators instead of hardcoded release constants;
• integrated release-identity regression coverage in Source Preflight;
• explicit Android ARM/ARM64/x86/x64 runtime identifiers;
• explicit iOS ARM64 device and ARM64/x64 simulator runtime identifiers;
• focused cross-platform source validation and GitHub Actions coverage;
• actions/checkout@v7 alignment for platform workflow contracts;
• retained deterministic SBOM, checksum, provenance, dependency-security, CodeQL, and release-evidence controls.

Core calculator

CalcNova includes a project-owned parser/evaluator rather than executing arbitrary user code.

Implemented capabilities include:

• safe tokenizer and recursive-descent parser;
• explicit operator precedence and right-associative exponentiation;
• parentheses and unary plus/minus;
• arbitrary-precision integers through System.Numerics.BigInteger;
• decimal arithmetic where appropriate with bounded floating-point fallback;
• typed calculation errors and workload limits;
• decimal and scientific-notation parsing;
• square, cube, arbitrary power, square/cube/nth root;
• reciprocal and absolute value;
• logarithmic and exponential functions;
• trigonometric, inverse-trigonometric, hyperbolic, and inverse-hyperbolic functions;
• degrees, radians, and gradians;
• floor, ceiling, truncation, rounding, sign, min, and max;
• factorial, GCD, LCM, combinations, and permutations;
• constants including π, e, and τ;
• calculator-style percentage handling separate from expression modulo;
• repeated-equals behavior;
• MC, MR, MS, M+, and M- memory operations;
• sanitized expression import and user-triggered clipboard paste;
• explicit copy-result workflow;
• top-row/numpad input and safe printable/shifted operator mappings outside active text editing;
• caret-aware insertion, forward/reversed selection replacement, selection deletion, Backspace-before-caret behavior, and selection-preserving wrapping.

Exact rational arithmetic

The exact-rational utility provides bounded BigInteger fraction arithmetic without converting finite decimal input through double first.

It includes:

• canonical numerator/denominator normalization;
• positive-denominator normalization;
• stable zero/default value semantics;
• exact integer, fraction, finite-decimal, and decimal-scientific parsing;
• exact addition, subtraction, multiplication, division, negation, reciprocal, comparison, equality, and hashing;
• cross-cancellation before multiplication;
• bounded raw input length, decimal scale/exponent magnitude, and reduced bit length;
• Calculator panel workflows for normalize/add/subtract/multiply/divide;
• source, application, and headless regression coverage;
• focused and integrated SDK-independent validation.

See docs/EXACT_RATIONALS.md.

Engineering notation

CalcNova includes a bounded engineering-notation formatter/parser for finite double values.

It provides:

• exponents in multiples of three;
• 1–15 significant digits;
• canonical invariant-culture parsing;
• explicit engineering exponent bounds from -324 through 306;
• non-zero-underflow rejection;
• chunked power-of-ten scaling for extreme finite values;
• a shared 4,096-character input budget across core parsing, formatting workflow, and UI text entry;
• Calculator panel format/parse workflows;
• focused validation and integrated source-preflight coverage.

See docs/ENGINEERING_NOTATION.md.

Programmer and Unicode tools

Programmer features include:

• base 2 through base 36 parsing, formatting, and shared UI selection;
• binary/octal/decimal/hex synchronized representations;
• 8/16/32/64/128-bit word-size presets;
• signed/unsigned two's-complement interpretation;
• fixed-width masked non-decimal displays;
• AND, OR, XOR, and NOT;
• left shift, logical right shift, and arithmetic right shift;
• full interactive bit grids with accessible bit labels;
• byte-grouped display for large word sizes;
• copy actions for radix and fixed-width bit representations.

Unicode tools include:

• Unicode scalar/code-point parsing and formatting;
• scalar-to-text conversion;
• bounded Unicode text inspection;
• local general-category metadata;
• Unicode plane metadata;
• UTF-8 byte-width and UTF-16 code-unit metadata;
• local-first metadata derivation with no network lookup;
• explicit result and metadata copy actions.

See docs/PROGRAMMER_MODE.md and docs/UNICODE_METADATA.md.

Unit conversion

Offline fixed-unit categories include:

• length;
• area;
• volume;
• mass;
• speed;
• temperature;
• time;
• data/storage;
• frequency;
• pressure;
• energy;
• power;
• force;
• angle.

The shared converter also supports:

• validated conversion pairs;
• unit swapping;
• selectable 1–17 significant-digit precision;
• category-scoped unit search;
• search-result assignment to From/To;
• bounded recent pairs;
• favorite pairs;
• pair restoration;
• clear-recents;
• result copy;
• persisted converter preferences;
• source contracts for preference/default behavior.

Fixed physical/data conversion remains local and offline.

Currency and date/time utilities

Currency infrastructure includes:

• replaceable rate-provider interface;
• local cache;
• offline fallback semantics;
• no embedded provider credentials.

Date/time utilities include:

• date difference;
• calendar arithmetic;
• business-day helpers;
• fixed-duration conversion.

Statistics

CalcNova provides descriptive and paired statistics.

Implemented paired analysis includes:

• bounded X/Y dataset parsing;
• population covariance;
• sample covariance;
• Pearson correlation when mathematically defined;
• ordinary least-squares regression slope/intercept;
• coefficient of determination (R²) when defined;
• prediction from the latest valid regression model;
• stale-model clearing after failed analysis;
• deterministic handling of mismatched, non-finite, oversized, constant-X, constant-Y, and single-pair datasets;
• summary copy workflow.

See docs/BIVARIATE_STATISTICS.md.

Equations and matrices

Equation tools include shared equation-solving workflows, including quadratic analysis.

Matrix capabilities include:

• determinant;
• inverse;
• rank;
• linear-system solving;
• shared result presentation;
• explicit result copy.

Graphing and numerical analysis

Graphing includes:

• y = f(x) sampling through the shared expression engine;
• workload-bounded sampling;
• discontinuity segmentation;
• explicit viewport model;
• focusable interactive Avalonia plot control;
• pointer drag panning;
• pointer-wheel zoom;
• double-tap/double-click fit-to-data;
• keyboard arrow-key panning;
• numpad Add/Subtract zoom;
• Home reset;
• F fit-to-data;
• accessible eight-action viewport toolbar for pan, zoom, reset, and fit;
• 44-DIP minimum toolbar action targets and keyboard focusability;
• nearest sampled-point trace;
• bounded single- and multi-expression CSV output;
• stable multi-series identities;
• deterministic non-color-only line patterns;
• synchronized multi-series text legend;
• accessible SVG export;
• bounded derivative approximation;
• bracketed bisection root finding;
• bounded Simpson integration;
• extreme-finite-value numerical safeguards;
• explicit numerical workload budgets.

Numerical analysis is approximate by design and is labeled accordingly.

See docs/GRAPH_INTERACTION.md, docs/NUMERICAL_ANALYSIS.md, and docs/GRAPH_NUMERICAL_SAFETY.md.

History, export, and persistence

History and persistence include:

• calculation-history abstraction;
• SQLite-backed native history;
• browser-safe storage path;
• recent/search/favorite/delete/clear workflows;
• bounded TXT/CSV/JSON export generation;
• bounded display previews with complete private copy payloads;
• reusable preview formatting with character/line limits, newline normalization, and UTF-16 boundary safety;
• settings repository abstraction;
• shared settings view model;
• persisted converter and culture preferences;
• explicit settings schema version;
• legacy and unversioned settings migration;
• fail-closed unsupported future-schema handling;
• shared JSON decoding/validation across native and Browser storage.

Accessibility and adaptive UI

The shared accessibility/adaptive baseline includes:

• 44-DIP minimum interaction-target baseline;
• 54-DIP standard calculator-key baseline;
• explicit visible keyboard focus styling;
• stronger focus styling under CalcNova high contrast;
• compact/medium/expanded layout profiles;
• compact horizontal-overflow fallback;
• focus bring-into-view behavior;
• Ctrl+PageUp/PageDown cyclic mode navigation;
• Ctrl+Home/End first/last mode navigation;
• keyboard-operable graph viewport;
• accessible programmer bit-state names;
• textual alternatives for non-color graph differentiation;
• reduced-motion/high-contrast preference state;
• onboarding focus/shortcut contracts;
• dynamic-control touch-target/focus validation;
• runtime evidence vocabulary using PASS / FAIL / BLOCKED / NOT RUN.

Runtime/device evidence is recorded conservatively; a source contract is not mislabeled as an observed device test.

Localization

CalcNova includes:

• stable semantic string keys;
• complete English semantic catalog for the current key set;
• complete Hindi semantic catalog for the current key set;
• regional English/Hindi culture selection such as en-IN and hi-IN;
• persisted culture preference;
• catalog completeness/duplicate/unknown-key validation;
• live localization for reviewed shell, calculator, onboarding, settings, history, currency, About, graph viewport actions, and related surfaces;
• Hindi labels for graph pan, zoom, reset, and fit controls.

Additional translations or further UI-string migration may be contributed as optional localization improvements; they are not required to define version 2.9.7 as complete.

Platforms

CalcNova contains composition heads for:

• Desktop — Windows, Linux, and macOS targets;
• Browser/WebAssembly/PWA;
• Android — android-arm, android-arm64, android-x86, and android-x64 source runtime identifiers;
• iOS — ios-arm64, iossimulator-arm64, and iossimulator-x64 source runtime identifiers.

The product display version for Android and iOS is 2.9.7, with numeric mobile build code 20907.

Desktop release source targets remain win-x64, win-arm64, linux-x64, linux-arm64, osx-x64, and osx-arm64.

Platform package generation still depends on the appropriate external SDK/workload, signing identity, and store credentials. Those environment requirements are separate from project implementation completeness.

Source validation and release evidence

CalcNova includes SDK-independent validators covering repository/security contracts, release identity, XAML, UI/navigation/keyboard behavior, graph/numerical contracts, Unicode, exact rationals, engineering notation, exports, bivariate statistics, accessibility/adaptive contracts, localization/settings, packaging metadata, platform workflows, cross-platform source composition, release workflows, artifact integrity, and structured release evidence.

Run the integrated source gate for the current release:

python tools/release_preflight.py --tag v2.9.7

Focused current-release checks include:

python -m unittest tools.tests.test_release_identity
python tools/validate_packaging_metadata.py .
python tools/validate_completion_status.py .
python tools/validate_platform_support.py .

Collect structured evidence:

python tools/run_release_evidence.py --scope source

The Source Preflight workflow watches source, tests, tooling, documentation, packaging, workflows, and relevant root build/release metadata. It is also protected by its own source validator.

See docs/SOURCE_PREFLIGHT.md, docs/VALIDATION_EVIDENCE.md, and docs/RELEASE_READINESS_CHECKLIST.md.

Release identity

Directory.Build.props is the source of truth. The shared release-identity helper verifies the central version fields agree, derives the mobile build code, and exposes the expected release tag to SDK-independent validators.

For CalcNova 2.9.7:

Product version: 2.9.7
Normalized package version: 2.9.7
Normalized release tag: v2.9.7
Assembly/file version: 2.9.7.0
Mobile build code: 20907

The release workflow verifies that the requested tag equals v plus the source <Version> before restore/build/test begins. The Android release job does not replace the product display version with tag text or GitHub run number.

See docs/VERSIONING.md.

Architecture

CalcNova keeps mathematical/domain projects independent of Avalonia UI where practical:

Platform heads
     │
     ▼
CalcNova.App
     │
     ├─────────────┬─────────────┬─────────────┐
     ▼             ▼             ▼             ▼
CalcNova.Core   feature libs   platform     persistence
                               contracts    implementations

Platform heads remain thin and contain startup, lifecycle, packaging, permissions, browser/native storage composition, external-link composition, and unavoidable native integration.

See docs/ARCHITECTURE.md.

Repository layout

CalcNova/
├── .github/
│   └── workflows/
├── docs/
│   └── releases/
├── packaging/
├── src/
│   ├── CalcNova.App/
│   ├── CalcNova.Core/
│   ├── CalcNova.Scientific/
│   ├── CalcNova.Programmer/
│   ├── CalcNova.Converter/
│   ├── CalcNova.Currency/
│   ├── CalcNova.DateTime/
│   ├── CalcNova.Graphing/
│   ├── CalcNova.Statistics/
│   ├── CalcNova.Equations/
│   ├── CalcNova.Matrices/
│   ├── CalcNova.Platform/
│   ├── CalcNova.Persistence/
│   ├── CalcNova.Desktop/
│   ├── CalcNova.Browser/
│   ├── CalcNova.Android/
│   └── CalcNova.iOS/
├── tests/
├── tools/
├── CalcNova.slnx
├── Directory.Build.props
├── Directory.Packages.props
├── PROJECT_STATE.md
└── what_changed.md

Build prerequisites

The repository pins a .NET 10 SDK feature band through global.json. Install the stable .NET SDK and platform workloads for the target you intend to build.

Run the SDK-independent source gate:

python tools/release_preflight.py --tag v2.9.7

Then run the compiled verification sequence in a suitable .NET environment:

dotnet restore CalcNova.slnx
dotnet format CalcNova.slnx --verify-no-changes --no-restore
dotnet build CalcNova.slnx --configuration Release --no-restore
dotnet test CalcNova.slnx --configuration Release --no-build

See docs/BUILDING.md and docs/TESTING.md.

Run the desktop application

dotnet run --project src/CalcNova.Desktop/CalcNova.Desktop.csproj

This requires a working .NET/Avalonia desktop environment.

Correctness and evidence policy

A feature is not considered runtime-verified merely because source code or tests exist. Build/test/platform evidence must be based on commands or workflows that actually ran and whose results were observed. When an environment is unavailable, evidence records NOT RUN or BLOCKED instead of inventing PASS.

This evidence policy does not change the product-completion status of version 2.9.7; it preserves accuracy about where a particular verification command was or was not executed.

Privacy

Core calculations, fixed conversions, exact rational arithmetic, engineering formatting, Unicode metadata, history, and settings are designed around local-first behavior. CalcNova does not require an account for ordinary calculation features, and the open-source base does not intentionally include advertising or behavioral-tracking SDKs.

Clipboard reads occur only after explicit user actions; imported expression text is sanitized. Network-enhanced currency refresh remains optional.

See docs/PRIVACY.md.

Contributing

Contributions for maintenance, compatibility, security, documentation, translations, tests, and optional enhancements are welcome. Read:

• CONTRIBUTING.md
• CODE_OF_CONDUCT.md
• SECURITY.md
• docs/ARCHITECTURE.md
• docs/TESTING.md

Security

Do not report sensitive vulnerabilities in a public issue. Follow SECURITY.md for private reporting guidance.

Support/security contact: supportramsandesh@gmail.com