71 lines
1.8 KiB
Scheme
71 lines
1.8 KiB
Scheme
(define-library (picrin repl)
|
|
(import (scheme base)
|
|
(scheme read)
|
|
(scheme file)
|
|
(scheme write)
|
|
(scheme eval)
|
|
(scheme process-context))
|
|
|
|
(define (file->string file)
|
|
(with-input-from-file file
|
|
(lambda ()
|
|
(let loop ((line (read-line)))
|
|
(if (eof-object? line)
|
|
""
|
|
(string-append line (loop (read-line))))))))
|
|
|
|
(define (print obj . port)
|
|
(write obj (if (null? port) (current-output-port) (car port)))
|
|
(newline)
|
|
obj)
|
|
|
|
(define (print-help)
|
|
(display "picrin scheme\n")
|
|
(display "\n")
|
|
(display "Usage: picrin [options] [file]\n")
|
|
(display "\n")
|
|
(display "Options:\n")
|
|
(display " -e [program] run one liner script\n")
|
|
(display " -h or --help show this help\n"))
|
|
|
|
(define (getopt)
|
|
(let ((args (cdr (command-line))))
|
|
(if (null? args)
|
|
#f
|
|
(case (string->symbol (car args))
|
|
((-h --help)
|
|
(print-help)
|
|
(exit 0))
|
|
((-e)
|
|
(cadr args))
|
|
(else
|
|
(file->string (car args)))))))
|
|
|
|
(define (main-loop)
|
|
(display "> ")
|
|
(let ((expr (read)))
|
|
(if (eof-object? expr)
|
|
(newline) ; exit
|
|
(begin
|
|
(call/cc
|
|
(lambda (leave)
|
|
(with-exception-handler
|
|
(lambda (condition)
|
|
(display (error-object-message condition))
|
|
(newline)
|
|
(leave))
|
|
(lambda ()
|
|
(print (eval expr '(picrin user)))))))
|
|
(main-loop)))))
|
|
|
|
(define (repl)
|
|
(let ((program (getopt)))
|
|
(parameterize
|
|
((current-input-port
|
|
(if program
|
|
(open-input-string program)
|
|
(current-input-port))))
|
|
(main-loop))))
|
|
|
|
(export repl))
|