Modernize and standardize and document.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,50 @@
+---
+name: Bug Report
+about: Create a report to help us improve
+title: '[BUG] '
+labels: bug
+assignees: ''
+---
+
+## Description
+A clear and concise description of what the bug is.
+
+## Steps to Reproduce
+Steps to reproduce the behavior:
+1. Parse expression '...'
+2. Create context with '...'
+3. Call evaluator with '...'
+4. See error
+
+## Expected Behavior
+A clear and concise description of what you expected to happen.
+
+## Actual Behavior
+What actually happened. Include error messages if applicable.
+
+## Code Example
+```dart
+// Minimal code example that reproduces the issue
+import 'package:expressions/expressions.dart';
+
+void main() {
+  var expr = Expression.parse('...');
+  var evaluator = const ExpressionEvaluator();
+  var result = evaluator.eval(expr, {...});
+  print(result); // Expected: X, Actual: Y
+}
+```
+
+## Environment
+* **Dart SDK version**: (run `dart --version`)
+* **Package version**: (check pubspec.yaml)
+* **Operating System**: (e.g., macOS 12.0, Ubuntu 20.04, Windows 11)
+
+## Additional Context
+Add any other context about the problem here, such as:
+* Does it work in previous versions?
+* Are there any error stack traces?
+* Any workarounds you've found?
+
+## Possible Solution
+If you have ideas on how to fix this, please share them here.

.github/ISSUE_TEMPLATE/feature_request.md

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+---
+name: Feature Request
+about: Suggest an idea for this project
+title: '[FEATURE] '
+labels: enhancement
+assignees: ''
+---
+
+## Is your feature request related to a problem?
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+
+## Proposed Solution
+A clear and concise description of what you want to happen.
+
+## Example Usage
+Show how you'd like to use the feature:
+```dart
+// Example of how the feature would work
+var expr = Expression.parse('...');
+// ... your proposed API usage
+```
+
+## Alternatives Considered
+A clear and concise description of any alternative solutions or features you've considered.
+
+## Additional Context
+Add any other context, mockups, or screenshots about the feature request here.
+
+## Implementation Ideas
+If you have thoughts on how this could be implemented, share them here. This is optional but helpful!
+
+## Breaking Changes
+Would this feature require breaking changes to the existing API?
+- [ ] Yes
+- [ ] No
+- [ ] Unsure
+
+## Workarounds
+Are there any current workarounds for this functionality?

.github/pull_request_template.md

@@ -0,0 +1,89 @@
+## Description
+<!-- Provide a brief description of the changes in this PR -->
+
+## Type of Change
+<!-- Mark the relevant option with an "x" -->
+- [ ] Bug fix (non-breaking change which fixes an issue)
+- [ ] New feature (non-breaking change which adds functionality)
+- [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
+- [ ] Documentation update
+- [ ] Performance improvement
+- [ ] Code refactoring
+- [ ] Test improvements
+- [ ] CI/CD improvements
+
+## Related Issues
+<!-- Link related issues here using keywords like "Fixes #123" or "Closes #456" -->
+Fixes #
+
+## Changes Made
+<!-- Provide a detailed list of changes -->
+-
+-
+-
+
+## Testing
+<!-- Describe the tests you ran and their results -->
+
+### Test Coverage
+- [ ] Unit tests added/updated
+- [ ] Integration tests added/updated
+- [ ] All tests pass locally (`dart test`)
+- [ ] Code coverage maintained or improved
+
+### Manual Testing
+<!-- Describe any manual testing performed -->
+```dart
+// Example code demonstrating the changes work as expected
+```
+
+## Documentation
+<!-- Check all that apply -->
+- [ ] Code includes dartdoc comments
+- [ ] README updated (if applicable)
+- [ ] CHANGELOG updated
+- [ ] Examples updated (if applicable)
+- [ ] CLAUDE.md updated (for architectural changes)
+
+## Code Quality
+<!-- Ensure these are checked before submitting -->
+- [ ] Code follows Dart style guidelines
+- [ ] Ran `dart format .` to format code
+- [ ] Ran `dart analyze` with no issues
+- [ ] No new warnings introduced
+- [ ] All linter rules pass
+
+## Breaking Changes
+<!-- If this PR includes breaking changes, describe them here -->
+<!-- Also describe migration path for users -->
+
+**Does this PR introduce breaking changes?**
+- [ ] Yes
+- [ ] No
+
+<!-- If yes, describe the breaking changes and migration path: -->
+
+## Performance Impact
+<!-- Describe any performance implications -->
+- [ ] No significant performance impact
+- [ ] Performance improved
+- [ ] Performance may be affected (explain below)
+
+<!-- Details: -->
+
+## Screenshots/Examples
+<!-- If applicable, add screenshots or example output to help explain your changes -->
+
+## Checklist
+<!-- Final checks before submitting -->
+- [ ] My code follows the project's coding standards
+- [ ] I have performed a self-review of my own code
+- [ ] I have commented my code where necessary
+- [ ] I have made corresponding changes to the documentation
+- [ ] My changes generate no new warnings
+- [ ] I have added tests that prove my fix/feature works
+- [ ] New and existing tests pass locally
+- [ ] Any dependent changes have been merged and published
+
+## Additional Notes
+<!-- Any additional information that reviewers should know -->

.github/workflows/dart.yml

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+name: Dart CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  test:
+    name: Test on ${{ matrix.os }} / Dart ${{ matrix.sdk }}
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        sdk: ['3.0.0', 'stable', 'beta']
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Dart
+        uses: dart-lang/setup-dart@v1
+        with:
+          sdk: ${{ matrix.sdk }}
+
+      - name: Install dependencies
+        run: dart pub get
+
+      - name: Verify formatting
+        run: dart format --output=none --set-exit-if-changed .
+        if: matrix.sdk == 'stable' && matrix.os == 'ubuntu-latest'
+
+      - name: Analyze code
+        run: dart analyze --fatal-infos
+
+      - name: Run tests
+        run: dart test
+
+  coverage:
+    name: Code Coverage
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Dart
+        uses: dart-lang/setup-dart@v1
+        with:
+          sdk: stable
+
+      - name: Install dependencies
+        run: dart pub get
+
+      - name: Collect coverage
+        run: dart test --coverage=coverage
+
+      - name: Format coverage
+        run: |
+          dart pub global activate coverage
+          dart pub global run coverage:format_coverage --lcov --in=coverage --out=coverage/lcov.info --packages=.dart_tool/package_config.json --report-on=lib
+
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v4
+        with:
+          files: coverage/lcov.info
+          fail_ci_if_error: true
+          token: ${{ secrets.CODECOV_TOKEN }}
+
+  documentation:
+    name: Generate Documentation
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Dart
+        uses: dart-lang/setup-dart@v1
+        with:
+          sdk: stable
+
+      - name: Install dependencies
+        run: dart pub get
+
+      - name: Generate documentation
+        run: dart doc --validate-links
+
+      - name: Deploy to GitHub Pages
+        if: github.ref == 'refs/heads/master' && github.event_name == 'push'
+        uses: peaceiris/actions-gh-pages@v3
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: ./doc/api
+          cname: false
+
+  publish-dry-run:
+    name: Publish Dry Run
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Dart
+        uses: dart-lang/setup-dart@v1
+        with:
+          sdk: stable
+
+      - name: Install dependencies
+        run: dart pub get
+
+      - name: Verify package
+        run: dart pub publish --dry-run

.gitignore

@@ -15,3 +15,6 @@ doc/api/
 *.ipr
 *.iws
 .idea/
+coverage/
+logs/
+CLAUDE.md