Language ======== Picrin's core language is the R7RS scheme with some powerful extensions. Please visit http://r7rs.org/ for the information of R7RS's design and underlying thoughts. The REPL -------- At the REPL start-up time, some usuful built-in libraries listed below will be automatically imported. - ``(scheme base)`` - ``(scheme load)`` - ``(scheme process-context)`` - ``(scheme write)`` - ``(scheme file)`` - ``(scheme inexact)`` - ``(scheme cxr)`` - ``(scheme lazy)`` - ``(scheme time)`` Compliance with R7RS --------------------- ================================================ ========== ========================================================================================================================== section status comments ================================================ ========== ========================================================================================================================== 2.2 Whitespace and comments yes 2.3 Other notations incomplete #e #i #b #o #d #x 2.4 Datum labels yes 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 yes As the report specifies, ``apply``, ``call/cc``, and ``call-with-values`` perform tail calls 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 incomplete ``include-ci`` 4.2.1 Conditionals incomplete TODO: ``cond-expand`` 4.2.2 Binding constructs yes 4.2.3 Sequencing yes 4.2.4 Iteration yes 4.2.5 Delayed evaluation N/A 4.2.6 Dynamic bindings yes 4.2.7 Exception handling no ``guard`` syntax. 4.2.8 Quasiquotation yes can be safely nested. TODO: multiple argument for unquote 4.2.9 Case-lambda N/A 4.3.1 Bindings constructs for syntactic keywords incomplete [#]_ 4.3.2 Pattern language yes ``syntax-rules`` 4.3.3 Signaling errors in macro transformers yes 5.1 Programs yes 5.2 Import declarations incomplete only simple import declarations, no support for import with renaming. 5.3.1 Top level definitions yes 5.3.2 Internal definitions yes TODO: interreferential definitions 5.3.3 Multiple-value definitions yes 5.4 Syntax definitions yes TODO: internal macro definition is not supported. 5.5 Recored-type definitions yes 5.6.1 Library Syntax incomplete In picrin, libraries can be reopend and can be nested. 5.6.2 Library example N/A 5.7 The REPL yes 6.1 Equivalence predicates yes TODO: equal? must terminate if circular structure is given 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 ``denominator``, ``numerator``, and ``rationalize`` are not supported for now. Also, picrin does not provide complex library procedures. 6.2.7 Numerical input and output incomplete only partial support supplied. 6.3 Booleans yes 6.4 Pairs and lists yes ``list?`` is safe for using against circular list. 6.5 Symbols yes 6.6 Characters yes 6.7 Strings yes 6.8 Vectors yes 6.9 Bytevectors yes 6.10 Control features yes 6.11 Exceptions yes ``raise-continuable`` is not supported 6.12 Environments and evaluation N/A 6.13.1 Ports yes 6.13.2 Input yes 6.13.3 Output yes 6.14 System interface yes ================================================ ========== ========================================================================================================================== .. [#] Picrin provides hygienic macros in addition to so-called legacy macro (``define-macro``), such as syntactic closure, explicit renaming macro, and implicit renaming macro. As of now let-syntax and letrec-syntax are not provided.