;;; "slib.scm" configuration template of slib:features for Scheme -*-scheme-*-
;;; Author: Shiro Kawai
;;; based on the "Template.scm" by Aubrey Jaffer
;;;
;;; This code is in the public domain.

;; SLIB module exports all symbols for compatibility.
(define-module slib
  (use srfi-0)
  (use srfi-13)
  (extend util.record)  ;; SLIB-compatible make-record-type
  (use file.util)
  (use gauche.uvector)  ;; Used to implement 'byte' API
  (export-all))
(select-module slib)

;;@ (software-type) should be set to the generic operating system type.
;;; unix, vms, macos, amiga and ms-dos are supported.
;;; NB [SK]: before slib 3a4 this returned captial symbols (e.g. UNIX),
;;; and there were code in require.scm that depended on them.  To keep
;;; backward compatibility,

(define software-type
  (let ((t (if (#/-mingw32$/ (gauche-architecture))
             '(ms-dos . MS-DOS)
             '(unix . UNIX))))
    (lambda ()
      (if (and (global-variable-bound? (current-module) '*SLIB-VERSION*)
               (string<? *SLIB-VERSION* "3a4"))
        (cdr t)
        (car t)))))

;After transition period, the above should be replaced by this:
;(define software-type
;  (let ((t (if (#/-mingw32$/ (gauche-architecture)) 'ms-dos 'unix)))
;    (lambda () t)))

;;@ (scheme-implementation-type) should return the name of the scheme
;;; implementation loading this file.
(define (scheme-implementation-type) 'gauche)

;;@ (scheme-implementation-home-page) should return a (string) URI
;;; (Uniform Resource Identifier) for this scheme implementation's home
;;; page; or false if there isn't one.
(define (scheme-implementation-home-page)
  "http://practical-scheme.net/gauche/")

;;@ (scheme-implementation-version) should return a string describing
;;; the version the scheme implementation loading this file.
(define (scheme-implementation-version) (gauche-version))

;;@ (implementation-vicinity) should be defined to be the pathname of
;;; the directory where any auxillary files to your Scheme
;;; implementation reside.
(define (implementation-vicinity)
  (string-append (gauche-library-directory) "/"))

;;@ (library-vicinity) should be defined to be the pathname of the
;;; directory where files of Scheme library functions reside.
(define library-vicinity
  (let ((library-path
         (or
          ;; Use this getenv if your implementation supports it.
          (sys-getenv "SCHEME_LIBRARY_PATH")
          ;; Use this path if your scheme does not support GETENV
          ;; or if SCHEME_LIBRARY_PATH is not set.
          (case (software-type)
            ((unix) "/usr/share/slib/")
            ((vms) "lib$scheme:")
            ((ms-dos) "C:\\SLIB\\")
            (else "")))))
    (lambda () library-path)))

;;@ (home-vicinity) should return the vicinity of the user's HOME
;;; directory, the directory which typically contains files which
;;; customize a computer environment for a user.
(define (home-vicinity)
  (let ((home (sys-getenv "HOME")))
    (and home
         (case (software-type)
           ((unix coherent ms-dos)      ;V7 unix has a / on HOME
            (if (eqv? #\/ (string-ref home (+ -1 (string-length home))))
              home
              (string-append home "/")))
           (else home)))))

;@
(define in-vicinity string-append)
;@
(define (user-vicinity)
  (case (software-type)
    ((vms)     "[.]")
    (else       "")))

(define *load-pathname* #f)
;@
(define vicinity:suffix?
  (let ((suffi
        (case (software-type)
          ((amiga)                             '(#\: #\/))
          ((macos thinkc)                      '(#\:))
          ((ms-dos windows atarist os/2)       '(#\\ #\/))
          ((nosve)                             '(#\: #\.))
          ((unix coherent plan9)               '(#\/))
          ((vms)                               '(#\: #\]))
          (else
           (slib:warn "require.scm" 'unknown 'software-type (software-type))
           "/"))))
    (lambda (chr) (and (memv chr suffi) #t))))
;@
(define (pathname->vicinity pathname)
  (let loop ((i (- (string-length pathname) 1)))
    (cond ((negative? i) "")
         ((vicinity:suffix? (string-ref pathname i))
          (substring pathname 0 (+ i 1)))
         (else (loop (- i 1))))))
(define (program-vicinity)
  (if *load-pathname*
      (pathname->vicinity *load-pathname*)
      (slib:error 'program-vicinity " called; use slib:load to load")))
;@
(define sub-vicinity
  (case (software-type)
    ((vms) (lambda
               (vic name)
             (let ((l (string-length vic)))
               (if (or (zero? (string-length vic))
                       (not (char=? #\] (string-ref vic (- l 1)))))
                 (string-append vic "[" name "]")
                 (string-append (substring vic 0 (- l 1))
                                "." name "]")))))
    (else (let ((*vicinity-suffix*
                 (case (software-type)
                   ((nosve) ".")
                   ((macos thinkc) ":")
                   ((ms-dos windows atarist os/2) "\\")
                   ((unix coherent plan9 amiga) "/"))))
            (lambda (vic name)
              (string-append vic name *vicinity-suffix*))))))
;@
(define (make-vicinity <pathname>) <pathname>)
;@
(define with-load-pathname
  (let ((exchange
         (lambda (new)
           (let ((old *load-pathname*))
             (set! *load-pathname* new)
             old))))
    (lambda (path thunk)
      (let ((old #f))
        (dynamic-wind
            (lambda () (set! old (exchange path)))
            thunk
            (lambda () (exchange old)))))))

;;@ SLIB:FEATURES is a list of symbols naming the (SLIB) features
;;; initially supported by this implementation.
(define slib:features
      '(
        source                          ;can load scheme source files
                                       ;(SLIB:LOAD-SOURCE "filename")
;;;    compiled                        ;can load compiled files
                                       ;(SLIB:LOAD-COMPILED "filename")
       vicinity
       srfi-59

                       ;; Scheme report features
   ;; R5RS-compliant implementations should provide all 9 features.

       r5rs                            ;conforms to
        eval                            ;R5RS two-argument eval
        values                          ;R5RS multiple values
        dynamic-wind                    ;R5RS dynamic-wind
        macro                           ;R5RS high level macros
        delay                           ;has DELAY and FORCE
        multiarg-apply                  ;APPLY can take more than 2 args.
        char-ready?
       rev4-optional-procedures        ;LIST-TAIL, STRING-COPY,
                                       ;STRING-FILL!, and VECTOR-FILL!

      ;; These four features are optional in both R4RS and R5RS

       multiarg/and-                   ;/ and - can take more than 2 args.
;       rationalize
;;;    transcript                      ;TRANSCRIPT-ON and TRANSCRIPT-OFF
       with-file                       ;has WITH-INPUT-FROM-FILE and
                                       ;WITH-OUTPUT-TO-FILE

       r4rs                            ;conforms to

        ieee-p1178                      ;conforms to

;;;    r3rs                            ;conforms to

;;;    rev2-procedures                 ;SUBSTRING-MOVE-LEFT!,
                                        ;SUBSTRING-MOVE-RIGHT!,
                                        ;SUBSTRING-FILL!,
                                        ;STRING-NULL?, APPEND!, 1+,
                                        ;-1+, <?, <=?, =?, >?, >=?
;;;    object-hash                     ;has OBJECT-HASH

       full-continuation               ;can return multiple times
        ieee-floating-point             ;conforms to IEEE Standard 754-1985
                                        ;IEEE Standard for Binary
                                        ;Floating-Point Arithmetic.

                        ;; Other common features

       ;; NB: we turned off srfi here, since if this is on, slib tries
       ;; to import all available srfis, including srfi-29, which defines
       ;; incompatible 'format'.
;       srfi                            ;srfi-0, COND-EXPAND finds all srfi-*
;;;    sicp                            ;runs code from Structure and
                                        ;Interpretation of Computer
                                        ;Programs by Abelson and Sussman.
        defmacro                        ;has Common Lisp DEFMACRO
        record                          ;has user defined data structures
        string-port                     ;has CALL-WITH-INPUT-STRING and
                                        ;CALL-WITH-OUTPUT-STRING
        sort
;;;    pretty-print
        object->string
;;;    format                          ;Common-lisp output formatting
;;;    trace                           ;has macros: TRACE and UNTRACE
;;;    compiler                        ;has (COMPILER)
;;;    ed                              ;(ED) is editor
        system                          ;posix (system <string>)
        getenv                          ;posix (getenv <string>)
        program-arguments               ;returns list of strings (argv)
        current-time                    ;returns time in seconds since 1/1/1970

                  ;; Implementation Specific features
       byte                            ;byte string manipulation
        ))

;; [SK] for backward compatibility
(define *features* slib:features)

;;@ (OUTPUT-PORT-WIDTH <port>)
(define (output-port-width . arg) 79)

;;@ (OUTPUT-PORT-HEIGHT <port>)
(define (output-port-height . arg) 24)

;;@ (CURRENT-ERROR-PORT) - Gauche has it
;(define current-error-port
;  (let ((port (current-output-port)))
;    (lambda () port)))

;;@ (TMPNAM) makes a temporary file name.
(define tmpnam sys-tmpnam)

;;@ SYSTEM
(define system sys-system)

;;@ GETENV
(define getenv sys-getenv)

;;@ (FILE-EXISTS? <string>)
; Gauche has this

;;@ (DELETE-FILE <string>)
(define (delete-file f) (sys-unlink f))

;;@ FORCE-OUTPUT flushes any pending output on optional arg output port
;;; use this definition if your system doesn't have such a procedure.
(define force-output flush)

;;@ CURRENT-TIME
(define current-time sys-time)

;;@ PROGRAM-ARGUMENTS
(define (program-arguments) (with-module gauche *argv*))

;;; CALL-WITH-INPUT-STRING and CALL-WITH-OUTPUT-STRING are the string
;;; port versions of CALL-WITH-*PUT-FILE.

;;@ "rationalize" adjunct procedures.
;;(define (find-ratio x e)
;;  (let ((rat (rationalize x e)))
;;    (list (numerator rat) (denominator rat))))
;;(define (find-ratio-between x y)
;;  (find-ratio (/ (+ x y) 2) (/ (- x y) 2)))

;;@ CHAR-CODE-LIMIT is one greater than the largest integer which can
;;; be returned by CHAR->INTEGER.
(define char-code-limit (+ *char-code-max* 1))

;;@ MOST-POSITIVE-FIXNUM is used in modular.scm
(define most-positive-fixnum (greatest-fixnum))

;;@ Return argument
;(define (identity x) x) ; Gauche has this.

;;@ SLIB:EVAL is single argument eval using the top-level (user) environment.
(define (slib:eval expr) (eval expr (interaction-environment)))

;; If your implementation provides R4RS macros:
(define macro:eval slib:eval)
;;@ %SLIB-LOAD loads file in slib module.
(define (%slib-load file)
  (with-module slib (load file)))
(define macro:load %slib-load)

(define-syntax defmacro
  (syntax-rules ()
    ((_ name params . body) (define-macro (name . params) . body))))

;; Gauche has these
; macroexpand-1
; macroexpand
;@
(define (gentemp) (gensym "slib:G"))

(define base:eval slib:eval)
;@
;(define (defmacro:eval x) (base:eval (defmacro:expand* x)))

;(define (defmacro:expand* x)
;  (require 'defmacroexpand) (apply defmacro:expand* x '()))
;@
(define defmacro:load %slib-load)
;; slib:eval-load definition moved to "require.scm"
;@
(define slib:warn
  (lambda args
    (let ((cep (current-error-port)))
      (if (provided? 'trace) (print-call-stack cep))
      (display "Warn: " cep)
      (for-each (lambda (x) (display #\space cep) (write x cep)) args)
      (newline cep))))

;;@ define an error procedure for the library
(define slib:error error)
;@
(define (make-exchanger obj)
  (lambda (rep) (let ((old obj)) (set! obj rep) old)))
(define (open-file filename modes)
  (case modes
    ((r rb) (open-input-file filename))
    ((w wb) (open-output-file filename))
    (else (slib:error 'open-file 'mode? modes))))
(define (port? obj) (or (input-port? obj) (output-port? obj)))
(define (call-with-open-ports . ports)
  (define proc (car ports))
  (cond ((procedure? proc) (set! ports (cdr ports)))
        (else (set! ports (reverse ports))
              (set! proc (car ports))
              (set! ports (reverse (cdr ports)))))
  (let ((ans (apply proc ports)))
    (for-each close-port ports)
    ans))
(define (close-port port)
  (cond ((input-port? port)
         (close-input-port port)
         (if (output-port? port) (close-output-port port)))
        ((output-port? port) (close-output-port port))
        (else (slib:error 'close-port 'port? port))))
;@
(define (browse-url url)
  (define (try cmd end) (zero? (system (string-append cmd url end))))
  (or (try "xdg-open '" "' &")
      (try "firefox '"  "' &")))

;;@ define these as appropriate for your system.
(define slib:tab (integer->char 9))
(define slib:form-feed (integer->char 12))

;;@ Support for older versions of Scheme.  Not enough code for its own file.
;(define (last-pair l) (if (pair? (cdr l)) (last-pair (cdr l)) l)) ; Gauche has this.
(define t #t)
(define nil #f)

;;; byte string operators.  SLIB's byte module assumes strings are
;;; a sequence of bytes.  In Gauche, it's not the case.  Furthermore,
;;; using a string as a mutable structure is very bad idea.  Here
;;; we use u8vector by default.  Unfortunately, some SLIB code assumes
;;; bytes === string, and passes a string directly to those APIs; so
;;; we have to deal with it.

(define (byte-ref s k)
  ((if (string? s) string-byte-ref u8vector-ref) s k))
(define (byte-set! s k b)
  ((if (string? s) string-byte-set! u8vector-set!) s k b))
(define make-bytes make-u8vector)
(define (bytes-length s)
  ((if (string? s) string-length u8vector-length) s))
(define bytes u8vector)
(define (bytes->list s)
  (u8vector->list (if (string? s) (string->u8vector s) s)))
(define list->bytes list->u8vector)
;; write-byte - Gauche has this
;; read-byte  - Gauche has this

;;@ Define these if your implementation's syntax can support it and if
;;; they are not already defined.
(define (1+ n) (+ n 1))
(define (-1+ n) (+ n -1))
(define 1- -1+)

;;@ Define SLIB:EXIT to be the implementation procedure to exit or
;;; return if exiting not supported.
(define slib:exit exit)

;;@ Here for backward compatability
(define scheme-file-suffix
  (let ((suffix (case (software-type)
                 ((nosve) "_scm")
                  (else ".scm"))))
    (lambda () suffix)))

;;@ (SLIB:LOAD-SOURCE "foo") should load "foo.scm" or with whatever
;;; suffix all the module files in SLIB have.  See feature 'SOURCE.
(define (slib:load-source f) (load (string-append f ".scm")))

;;@ (SLIB:LOAD-COMPILED "foo") should load the file that was produced
;;; by compiling "foo.scm" if this implementation can compile files.
;;; See feature 'COMPILED.
(define slib:load-compiled load)

;;@ At this point SLIB:LOAD must be able to load SLIB files.
(define slib:load load)

(slib:load (in-vicinity (library-vicinity) "require"))

;;; A trick to make require work both on Gauche files and slib files.
;;; The hint is taken from STk.

(define-macro (require feature)         ;redefine
  (if (string? feature)
    `',(%require feature)            ;gauche version
    `(slib:require ,feature)))    ;slib version

(define (provide feature)
  (if (string? feature)
    (with-module gauche (provide feature)) ;gauche version
    (slib:provide feature)))       ;slib version

(define (provided? feature)
  (if (string? feature)
    (with-module gauche (provided? feature)) ;gauche version
    (slib:provided? feature)))     ;slib version

(provide "slib")
