62 lines
2.6 KiB
Scheme
62 lines
2.6 KiB
Scheme
(import (scheme base) (scheme char) (scheme file)
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(scheme read) (scheme write))
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(define (read-declarations-from-file filename)
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(let ((bytes (let ((bytes (call-with-port
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(open-binary-input-file filename)
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(lambda (port) (read-bytevector 1000 port)))))
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(if (eof-object? bytes) (make-bytevector 0) bytes)))
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(i 0))
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(define (peek-next-ascii-byte)
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(if (not (< i (bytevector-length bytes)))
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(eof-object)
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(let ((next-byte (bytevector-u8-ref bytes i)))
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(if (<= 1 next-byte 126)
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next-byte
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(begin (set! i (+ i 1))
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(peek-next-ascii-byte))))))
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(define (read-char? k)
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(let* ((next-byte (peek-next-ascii-byte))
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(next-char (if (eof-object? next-byte)
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next-byte (integer->char next-byte)))
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(consume? (cond ((procedure? k) (k next-char))
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((char? k) (eqv? k next-char))
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(else #f))))
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(cond (consume? (set! i (+ i 1)) next-char)
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(else #f))))
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(define (read-char* k)
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(let loop ((chars '()))
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(let ((c (read-char? k)))
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(if c (loop (append chars (list c)))
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(if (null? chars) #f (list->string chars))))))
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(define (symbol-char? c)
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(not (or (eof-object? c) (char-whitespace? c)
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(eqv? c #\") (eqv? c #\() (eqv? c #\)))))
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(define (read->eol)
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(read-char* (lambda (c) (not (eqv? c #\newline)))))
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(define (skip-white-comm)
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(cond ((read-char? #\;) (read->eol) (skip-white-comm))
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((read-char? char-whitespace?) (skip-white-comm))
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(else #f)))
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(define (read-lexeme)
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(skip-white-comm)
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(cond ((read-char? #\()) ((read-char? #\))) ((read-char* symbol-char?))
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(else #f)))
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(let* ((shebang (and (read-char? #\#) (read-char? #\!) (read->eol))))
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(cons shebang
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(and (eqv? (read-lexeme) #\() (equal? (read-lexeme) "declare-file")
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(eqv? (read-lexeme) #\() (equal? (read-lexeme) "coding")
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(let ((coding (read-lexeme)))
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(and (string? coding) (eqv? (read-lexeme) #\))
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(string-downcase coding))))))))
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(define (writeln x)
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(write x)
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(newline))
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(writeln (read-declarations-from-file "test-big5.scm"))
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(writeln (read-declarations-from-file "test-euc-jp.scm"))
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(writeln (read-declarations-from-file "test-shift-jis.scm"))
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(writeln (read-declarations-from-file "test-utf16-be.scm"))
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(writeln (read-declarations-from-file "test-utf16-le.scm"))
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