Ruby Blocks

Origins and Nature of Ruby Blocks

• Many comments connect Ruby’s block model to Smalltalk and functional languages: blocks are closures that capture their environment and can be passed around or deferred.
• A central nuance: Ruby has two closure styles:
  • Lambdas: return exits the lambda and argument checking is strict, like methods.
  • Procs/blocks: return is non‑local – it exits the defining method; break/next also have special semantics.
• This duality is powerful (early exits, generator-style patterns) but widely seen as confusing for newcomers, especially since lambdas, procs, and blocks all involve Proc objects with different control-flow behavior.

Scope, Control Flow, and “Recklessness”

• There’s debate over how “reckless” Ruby’s closure features are:
  • One side: Ruby allows transplanting blocks into different scopes and using metaprogramming (instance_eval, etc.), which can lead to subtle bugs and hard-to-debug DSLs.
  • Other side: this is the essence of closures; used carefully (e.g., avoiding return in shared procs), it enables elegant abstractions without boilerplate classes.

Objects, Message Passing, and 5.times

• Long discussion around 5.times { ... }:
  • Pro‑Ruby view: in a deeply OO, message-passing system where everything (including integers and booleans) is an object, “5 receives a times message” is coherent and reads well.
  • Skeptical view: times conceptually belongs on the block, not the number; syntax feels like a “hack” for pretty code and blurs noun/verb roles.
• This ties into message passing vs method calling: Ruby routes messages via __send__ and method_missing, enabling proxies and dynamic APIs, but also obscuring what exists at compile time.

First-Class Functions and Alternatives

• Several comments show Ruby’s more explicit functional side: lambdas (-> {}), method objects (obj.method(:foo)), and the & operator to turn them into blocks for map, filter, etc.
• Some find Ruby blocks limiting compared to languages where ordinary functions are passed directly; others argue Ruby effectively supports both styles.

Power, DSLs, and Metaprogramming

• Blocks plus method_missing and instance_eval are credited for Ruby’s DSLs (Rails, RSpec, Cucumber). They make creating “English-like” APIs easy but can harm clarity and tooling.
• Some advise using blocks freely but treating method_missing and heavy metaprogramming with caution in shared codebases.

Readability, Tooling, and Ecosystem

• Enthusiasts describe a “Ruby moment” where the syntax suddenly feels natural and joyful; detractors see over‑cute, English‑like code that hinders maintainability.
• Tooling (LSP, autocomplete, navigation) is widely seen as weaker than in more static ecosystems, partly due to runtime dynamism.
• Gradual typing (Sorbet, RBS, RBS‑inline) is mentioned but opinions differ on its maturity and impact; some view lack of strong typing as limiting Ruby’s growth (e.g., for infrastructure‑as‑code).

Community and Trajectory

• Commenters note Ruby’s influence on newer languages (especially Kotlin) and its lasting niche despite Python’s dominance.
• Several newcomers express excitement at learning Ruby now; veterans remain fond of it for quick, expressive coding even if market share is declining.