June 2026 monthly summary for developer work focused on internal parser correctness and stability improvements across ruby/ruby and ruby/prism. The primary deliverable was a binding-power predicate handling refactor that replaces ad-hoc +1 semantics with a named constant (PM_BINDING_POWER_COMPOSITION), improving parsing correctness and clarity, particularly for conditional predicates such as while/until. No user-facing features were shipped this month; the emphasis was on code quality, consistency, and maintainability, enabling more reliable parsing behavior and easier future enhancements.

May 2026 monthly summary focused on parser correctness and error handling for modifier conditionals across the Prism/Ruby codebase. Implemented cross-repo alignment to ensure parse.y and Prism treat modifier conditionals consistently for if/unless/elsif, matching the behavior of while/until. This involved raising the floor of the left-binding power to PM_BINDING_POWER_MODIFIER + 1 and propagating changes to ruby/ruby to maintain uniform error reporting and parsing semantics. Key commit references include 0fa8d8f8d87bc09093d03bbaec755149290ad683 in ruby/prism and 9e8ad9ac0489d8390bc11e5b18f4af065d60898c in ruby/ruby. Impact: reduces syntax error noise and misparsing for modifier conditionals, improving developer experience and reliability for code that relies on predicate binding powers. This strengthens the consistency between Prism-based parsing and core Ruby, enabling safer refactors and downstream tooling."