Set Literal Syntax (#{...}) for PTC-Lisp

[andreasronge]

Set Literal Syntax (#{...}) for PTC-Lisp

Overview

Add Clojure-style #{...} set literal syntax to PTC-Lisp. Sets are currently explicitly not supported (LLMs commonly use this syntax causing parse errors). This epic implements MapSet-based sets with O(1) membership, silent deduplication, and minimal operations.

Specification Documents

• Set Literal Implementation Plan - Complete implementation guide with code examples, edge cases, and tests

Progress

Phase 1: Parser

• Add \#{...} set literal parsing to PTC-Lisp parser #165 - Add #{...} parsing to parser.ex and parser_helpers.ex

Phase 2: AST Types

• Add {:set, [t()]} to AST type specifications (Phase 2 of #164) #167 - Add {:set, [t()]} to ast.ex and core_ast.ex type specs

Phase 3: Analyzer

• Add set analysis to analyze.ex (Phase 3 of #164) #169 - Add set analysis to analyze.ex

Phase 4: Evaluator

• Add set evaluation to eval.ex (Phase 4 of #164) #171 - Add set evaluation to eval.ex (returns MapSet)

Phase 5: Runtime (Critical - MapSet/is_map fix)

• Add set runtime support: set?, set, and MapSet-safe collection ops (Phase 5 of #164) #174 - Add set?, set functions and MapSet-safe collection ops

Phase 6: Formatter

• Add set formatting to formatter.ex (Phase 6 of #164) #177 - Add set formatting to formatter.ex (escape # properly)

Phase 7: Documentation

• Add set literal documentation (Phase 7 of #164) #179 - Add set literal documentation (ptc-lisp-specification.md and ptc-lisp-llm-guide.md)

Phase 8: Tests

• Parser tests (empty set, nested, errors) - Added in Phase 1
• Analyzer tests - Added in Phase 3
• Evaluator tests (dedup, predicates, operations) - Added in Phase 4
• [From PR #175] Add test coverage for remove, mapv, empty?, and count on sets #176 - Add test coverage for remove, mapv, empty?, and count on sets

Notes

Critical regression risk in Phase 5: MapSet is a struct, so is_map(%MapSet{}) returns true. All functions with when is_map(coll) guards will incorrectly match MapSet and crash (expecting {k, v} tuples). Must add explicit %MapSet{} clauses BEFORE generic is_map clauses.

Design decisions:

• Silent deduplication (#{1 1 2} → #{1 2}) for LLM-friendliness
• coll? returns false for sets (separate set? predicate)
• Collection ops (map, filter, remove) return vectors, not sets

[andreasronge]

Progress Update

• Created: Add \#{...} set literal parsing to PTC-Lisp parser #165 - Add #{...} set literal parsing to PTC-Lisp parser
• Status: Issue created and linked to Phase 1: Parser task
• Next: Awaiting review approval for Add \#{...} set literal parsing to PTC-Lisp parser #165 before implementation can begin

[andreasronge]

Progress Update

• Completed: Add \#{...} set literal parsing to PTC-Lisp parser #165 (Phase 1: Parser) - merged in PR feat(parser): Add #{...} set literal syntax support (Phase 1 of #164) #166
• Created: Add {:set, [t()]} to AST type specifications (Phase 2 of #164) #167 (Phase 2: AST Types) - waiting for review
• Next: Once Add {:set, [t()]} to AST type specifications (Phase 2 of #164) #167 passes review, implementation can proceed

[andreasronge]

Progress Update

• Completed: Add {:set, [t()]} to AST type specifications (Phase 2 of #164) #167 - AST Types (Phase 2) - merged in PR feat: Add {:set, [t()]} to AST type specifications #168
• Created: Add set analysis to analyze.ex (Phase 3 of #164) #169 - Analyzer (Phase 3) - now pending review
• Next: Once Add set analysis to analyze.ex (Phase 3 of #164) #169 passes review, it will be ready for implementation