prometeu-studio/docs/pbs/pull-requests/PR-015-pbs-this-self-context-validation.md

PR-015 - PBS this/Self Context Validation

Briefing

The frontend accepts this and Self outside allowed contexts without required diagnostics. This PR adds explicit static checks for invalid usage.

Motivation

Context-free acceptance of this/Self is non-conformant and creates type ambiguity.

Target

• this expression analysis.
• Self type-surface analysis in declarations.
• Error catalog and deterministic diagnostics.

Scope

• Reject this outside struct method, service method, and ctor bodies.
• Reject Self outside struct/service method declarations and ctors.

Method

• Add callable-context metadata into flow/type validation.
• Emit dedicated diagnostics for invalid this and invalid Self usage.
• Keep valid owner contexts unchanged.

Acceptance Criteria

• Invalid this usage emits deterministic static diagnostic.
• Invalid Self usage emits deterministic static diagnostic.
• Valid struct/service/ctor contexts remain accepted.

Tests

• Add positive tests for valid this/Self contexts.
• Add negative tests for top-level functions and unrelated declarations.
• Run declaration + flow semantic suites.

Non-Goals

• Introducing new receiver features.
• Altering Self syntax.