delphi-conventions

Delphi Conventions — Rules

Nomenclatura

• PascalCase for all identifiers
• Reserved words in lowercase (begin, end, if, nil, string)
• Prefixes: T (classes), I (interfaces), E (exceptions), F (private fields), A (parameters), L (local variables)
• Units: Projeto.Camada.Dominio.Funcionalidade.pas
• Components: 3-letter prefix (btn, edt, lbl, cmb, pnl, qry, ds)

Formatting

• Indentation: 2 spaces
• Limit: 120 characters per line
• begin on the same line for if/for/while blocks
• begin on new line for method body

Unit Mandatory Sections

unit Nome;
interface
uses { ... };
type { Enums → Interfaces → Classes }
implementation
uses { imports extras };
{ Implementação agrupada por classe }
end.

Documentation

• XMLDoc for public methods and properties
• Comments in Portuguese for Brazilian projects
• Do not comment self-explanatory code

Memory Management

• try/finally with Free for temporary objects
• Interfaces for automatic reference counting
• Local variables with prefix L
• Owner pattern for visual components

Prohibitions

• ❌ with statement
• ❌ Global variables
• ❌ Generic Catch (except on E: Exception) in business/domain code — allowed only at top-level boundaries (thread roots, request handlers, application-level last-resort handlers) where it must log and re-raise or translate, never swallow
• ❌ Magic numbers — use constants
• ❌ Hardcoded strings — use resourcestring or constants
• ❌ Methods > 20 lines