Run2 scala idiomatic patterns

Idiomatic Scala Patterns

Enums (Scala 2.13)

Use sealed abstract class with companion object containing case objects:

sealed abstract class TokenType(val value: String)
object TokenType {
  case object STRING extends TokenType("string")
}

Case Classes for Immutable Data

• Python @dataclass(frozen=True) -> Scala case class
• Use copy() for creating modified instances
• Default params replace field(default_factory=...)

Naming Conventions

• camelCase for methods/fields: tokenize_batch -> tokenizeBatch
• PascalCase for types: same in both languages
• Avoid _ prefix for private fields; use private modifier

Avoid var and return

• Use Option chains, match, and foldLeft instead of mutable vars
• Use expression-oriented style: every block returns a value
• Prefer val over var wherever possible

Pattern Matching over isinstance

Python isinstance(value, (str, bytes)) becomes Scala pattern matching:

value match {
  case s: String => ...
  case d: Double => ...
}