This product is developed at the second-grade course, Informatic Science Basic Experiment class at the University of Tokyo. # Picrin - a lightweight scheme interpreter ## Features - R7RS compatibility (but partial support) - reentrant design (all VM states are stored in single global state object) - bytecode interpreter (based on Stack VM technology) - direct threaded VM - Internal representation by Nan-Boxing - conservative call/cc implementation (users can freely interleave native stack with VM stack) - exact GC (simple mark and sweep strategy) - advanced REPL support (multi-line input, etc) - tiny & portable library (all functions will be in `libpicrin.so`) ## Supported Range | section | status | comments | | --- | --- | --- | | 2.2 Whitespace and comments | incomplete | block comments are not implemented | | 2.3 Other notations | incomplete | #e #i #b #o #d #x | | 2.4 Datum labels | no | unsupported | | 3.1 Variables, syntactic keywords, and regions | | | | 3.2 Disjointness of types | yes | | | 3.3 External representations | | | | 3.4 Storage model | yes | | | 3.5 Proper tail recursion | incomplete | apply, call/cc, call/values, eval are not yet | | 4.1.1 Variable references | yes | | | 4.1.2 Literal expressions | yes | | | 4.1.3 Procedure calls | yes | In picrin `()` is self-evaluating | | 4.1.4 Procedures | yes | | | 4.1.5 Conditionals | yes | In picrin `(if #f #f)` returns `#f` | | 4.1.6 Assignments | yes | | | 4.1.7 Inclusion | no | `include` and `include-ci` | | 4.2.1 Conditionals | incomplete | TODO: `cond-expand` | | 4.2.2 Binding constructs | incomplete | TODO: `let-values`, `let*-values` | | 4.2.3 Sequencing | yes | | | 4.2.4 Iteration | no | | | 4.2.5 Delayed evaluation | N/A | | | 4.2.6 Dynamic bindings | no | TODO: `make-parameter`, `parameterize` in C level | | 4.2.7 Exception handling | no | `guard` syntax. | | 4.2.8 Quasiquotation | incomplete | nested is unsupported | | 4.2.9 Case-lambda | N/A | | | 4.3.1 Bindings constructs for syntactic keywords | no | Instead, picrin provides so-called legacy macro facility (`define-macro`). | | 4.3.2 Pattern language | no | see above. | | 4.3.3 Signaling errors in macro transformers | no | see above. | | 5.1 Programs | yes | | | 5.2 Import declarations | no | | | 5.3.1 Top level definitions | yes | | | 5.3.2 Internal definitions | no | | | 5.3.3 Multiple-value definitions | no | | | 5.4 Syntax definitions | no | see notes on section 4.3.1. | | 5.5 Recored-type definitions | no | | | 5.6.1 Library Syntax | no | | | 5.6.2 Library example | N/A | | | 5.7 The REPL | yes | | | 6.1 Equivalence predicates | yes | | | 6.2.1 Numerical types | yes | picrin has only two types of internal representation of numbers: fixnum and double float. It still comforms the R7RS spec. | | 6.2.2 Exactness | yes | | | 6.2.3 Implementation restrictions | yes | | | 6.2.4 Implementation extensions | yes | | | 6.2.5 Syntax of numerical constants | yes | | | 6.2.6 Numerical operations | yes | some functions that return multiple values are not supported for now. Also, picrin does not provide complex library procedures. | | 6.2.7 Numerical input and output | no | | | 6.3 Booleans | yes | | | 6.4 Pairs and lists | yes | | | 6.5 Symbols | yes | | | 6.6 Characters | incomplete | TODO: almost all functions in the section :-( | | 6.7 Strings | incomplete | | | 6.8 Vectors | incomplete | TODO: `vector-copy`, ...etc | | 6.9 Bytevectors | incomplete | TODO: string<->utf8 conversion, etc | | 6.10 Control features | incomplete | TODO: `string-map`, `vector-map`, ...etc | | 6.11 Exceptions | no | | | 6.12 Environments and evaluation | no | | | 6.13 Ports | incomplete | | | 6.14 System interface | incomplete | `exit` is unsafe when used with dynamic-wind | ## Homepage Currently picrin is hosted on Github. You can freely send a bug report or pull-request, and fork the repository. https://github.com/wasabiz/picrin ## How to use it - build $ make build built executable binary will be under bin/ directory and shared library `libpicrin.so` under lib/. - run Simply directly run the binary `bin/picrin` from terminal, or you can use `make` to execute it like this. $ make run - debug-run By default make command runs REPL with all debug flags enabled. $ make In the default option, when `make` command is called without arguments, it builds the binary and right after that dropped into the picrin interactive shell (REPL). - install As of now picrin does not provide a command automatically installs the binary. If you want to place picrin library and binary in a parmanent directory, please do it by hand. ## Requirement picrin scheme depends on some external libraries to build the binary: - bison - yacc - make - gcc - readline The compilation is tested only on Mac OSX. I think (or hope) it'll be ok to compile and run on other operating systems such as Linux or Windows, but there's no guarantee :( ## Authors Yuichi Nishiwaki (yuichi.nishiwaki at gmail.com)