PicoRuby Development Constraints

记录PicoRuby在ESP32上的内存限制和stdlib约束。在编写将在ESP32硬件上运行的代码或为PicoRuby应用设计功能时使用。

SKILL.md

--- frontmatter

name: PicoRuby Development Constraints
description: Documents memory limits and stdlib constraints for PicoRuby on ESP32. Use this when writing code that will run on ESP32 hardware or designing features for PicoRuby applications.

PicoRuby Development Constraints

Memory constraints and stdlib limitations for ESP32 PicoRuby development.

Memory & Runtime Limits

•Total heap: 520KB (strict limit)
•Nesting depth: Avoid deep recursion; prefer iterative solutions
•String handling: Pre-allocate when possible; avoid repeated concatenation
•Arrays: Use fixed-size when known; minimize dynamic growth during tight loops

PicoRuby vs CRuby

Feature	PicoRuby	CRuby
Gems	❌ No bundler/gems	✅ Full ecosystem
stdlib	Minimal (R2P2-ESP32 only)	Complete stdlib
Memory	~520KB heap	GB+ available
GC	Simple mark-sweep	Complex generational
Float math	⚠️ Limited precision	Full IEEE 754

PicoRuby-safe stdlib

Available:

•Array#each, #map, #select (avoid #each_with_index in tight loops)
•Hash (simple key-value)
•String (basic methods, avoid regex for embedded)
•Time (limited; ESP32 time depends on system clock)
•File (via R2P2-ESP32 abstraction)

Unavailable:

•Regex (use string matching instead)
•Threads (single-threaded runtime)
•Fiber/Enumerator (complex control flow not needed)