scala-naming-conventions-and-style

name	scala-naming-conventions-and-style
description	Scala-specific naming conventions, code organization patterns, and style guidelines that differ from Python conventions.

Scala Naming Conventions

Classes, Traits, and Objects

• PascalCase for class names: TokenType, BaseTokenizer, UniversalTokenizer
• PascalCase for trait names and sealed traits
• camelCase for object names if singleton: TokenizerBuilder (if companion object, use same name as class)
• UPPER_SNAKE_CASE for constants and enum-like values

Functions and Variables

• camelCase for method and variable names: tokenize, tokenizeBatch, toToken, withMetadata
• camelCase for parameters: input, maxLength, delimiter
• Use descriptive names; avoid single letters except in lambda expressions or mathematical contexts

Package Organization

• Lowercase package names: com.example.tokenizer
• Structure: separate classes/traits from utility objects
• One public class per file is conventional (but not required)

Code Style

• No underscore prefix for private fields; use private modifier
• Prefer val over var (immutability first)
• Use method chaining and builder patterns for fluent APIs
• Indent with 2 spaces (Scala convention)

Scala-Specific Patterns

Sealed Traits for Enums

sealed trait TokenType
case object StringToken extends TokenType
case object NumericToken extends TokenType

Case Classes for Data

case class Token(
  value: String,
  tokenType: TokenType,
  position: Int,
  metadata: Map[String, String] = Map.empty
)

Builder Pattern

class TokenizerBuilder {
  private var config: Map[String, Any] = Map.empty
  def withOption(key: String, value: Any): TokenizerBuilder = {
    config = config + (key -> value)
    this
  }
  def build(): Tokenizer = new Tokenizer(config)
}