Practical language use.
WHAT TO USE FOR DATA CARRIERS
Records, which provide value equality and concise declaration.
WHAT TO ENABLE
Nullable reference types.
WHY
It makes absence explicit in the type system, addressing the commonest runtime error.
WHAT TO USE FOR COLLECTIONS
The standard collections, chosen by the operations you perform.
WHAT THE QUERY FACILITIES PROVIDE
Filtering, projecting and aggregating collections declaratively.
WHAT TO BE CAREFUL WITH
Deferred execution, where a query runs when enumerated rather than when defined.
WHAT THAT CAUSES
Queries executing more than once, or against changed data.
WHAT TO DO ABOUT IT
Materialise explicitly when you need the results.
WHAT THE ASYNCHRONOUS MODEL PROVIDES
Non-blocking operations, written sequentially.
WHAT TO NEVER DO
Block on an asynchronous operation.
WHY
It causes deadlocks and exhausts threads under load.
WHAT TO USE FOR MONEY
The decimal type, never floating point.
WHAT TO USE FOR DISPOSABLE RESOURCES
The construct guaranteeing cleanup.
WHAT TO PREFER
Immutability where practical, and explicit over implicit.
