Python · C#
Class Design
Internal by default, behavior-only classes against state-only types, the two sanctioned uses of interfaces, and closing concrete descendants.
PWI pillar
Programming with Intent
Classes, methods, naming, and the shape of everyday code. The rules that apply to almost every file you touch.
13 topics. Chapter numbers are deliberately absent, because the two language families number their chapters independently.
Python · C#
Method Design
C# methods tell callers what they do through explicit visibility, truthful signatures, and returns that express action, query, and cardinality; their bodies orchestrate at one level.
Python · C#
Naming Conventions
Deriving names rather than inventing them, domain suffixes over indices, the Async exception, and why Retrieve and Search choose different failure contracts.
Factory Pattern
A Factory selects and constructs a concrete descendant while callers program to an interface through the base class's public contract. C# thumbnailers show selection and polymorphic dispatch.
Factory Method Pattern
Factory Method lets consumer subclasses choose dependencies through an overridable creation hook. C# examples show its two class families and distinguish it from a separate Factory.
Type Annotations
Annotations as intent rather than decoration: None used deliberately, dictionaries kept out of method boundaries, and capability types that tell the truth.
LINQ Query Semantics
A query does not run when you write it, and calling it twice may not give the same answer. Deferred execution, materialization, terminal operators, and untranslatable queries.
Not yet published
- Anti-Patterns
- Code Correctness and Runtime Safety
- Intentional Model Design
- Adapter Pattern
- Decorator Pattern
Marked language-independent on the assumption this is the GoF pattern. If the chapter is about Python's @ decorator syntax, scope should be 'python'.
- Python Language Style