Releases · PikachuHy/pscm

14 Dec 13:22

PikachuHy

v0.5.0

45ffdbd

PikachuHy's Scheme support Continuation now Latest

Latest

Release Date: 20251214

We are pleased to announce the release of pscm v0.5.0.

This is a significant milestone release. Almost all of the code was written with AI assistance in Cursor after commit 8380f9c , demonstrating the power of AI-assisted development in building complex language implementations.

This version implements complete Scheme core functionality with approximately 11,000+ lines of code. Designed with reference to Guile 1.8, it provides continuation support based on setjmp/longjmp, enabling advanced control flow patterns that are essential for Scheme programming.

🎉 What's New

Complete Scheme Core Implementation

Full type system with 17 data types
Comprehensive parser and evaluator
Continuation support via setjmp/longjmp
Rich built-in function library
Enhanced error handling with stack traces

Key Features

Type System: Unified SCM type supporting 17 data types including NIL, LIST, NUM, FLOAT, RATIO, CHAR, STR, SYM, BOOL, PROC, FUNC, CONT, MACRO, HASH_TABLE, VECTOR, PORT
Continuation Support: First-class continuations implemented using setjmp/longjmp with dynamic-wind support
Parser: Hand-written recursive descent parser with full Scheme syntax support
Evaluator: Tail-recursive optimized evaluator with modular special form handling
Error Handling: Enhanced error reporting with source location tracking and call stack traces (up to 20 levels)

📦 Core Functionality

Data Structures

Lists with dotted pair support
Lexical scoping with environment chains
Hash tables with three equality modes (eq?, eqv?, equal?)
Fixed-length vectors with random access

Built-in Functions

Comprehensive library including:

Type predicates: procedure?, boolean?, null?, pair?, char?, number?
List operations: car, cdr, cons, list, append, set-car!, set-cdr!
Numeric operations: +, -, *, /, expt, abs (with mixed integer/float/ratio support)
String and character operations
Vector operations
Hash table operations
Port operations (file and string ports)
System operations: exit

Special Forms

define, lambda, if, cond, case, and, or, begin, let/let*/letrec, do, for-each, map, quote, quasiquote, apply, call/cc, call-with-values, dynamic-wind

C/C++ Integration

Guile 1.8-compatible function registration:

Fixed parameters: scm_define_function
Generic functions: scm_define_generic_function
Variadic functions: scm_define_vararg_function

⚠️ Known Limitations

Memory Management: No garbage collection (GC) implemented yet. All allocated memory is not freed, which may cause memory leaks.
Error Handling: Most errors result in exit(1), lacking graceful error recovery mechanisms (though call stack tracing is available).
Performance: Environment lookup uses linear search (O(n)), and symbol comparison uses memcmp.
Missing Features: Module system, file loading functions (load), Guile API compatibility layer.