67 lines
2.1 KiB
Scheme
67 lines
2.1 KiB
Scheme
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(library (ikarus io-primitives unsafe)
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(export $write-char $read-char $unread-char $peek-char
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$reset-input-port! $flush-output-port
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$close-input-port $close-output-port)
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(import
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(ikarus)
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(only (scheme) $port-handler $port-output-buffer
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$set-port-output-index! $port-output-size
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$set-port-input-index! $port-input-buffer $port-input-size
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$set-port-input-size!
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$port-input-index
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$fxadd1 $fxsub1 $fx< $fx>= $string-ref
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$string-length $string-set!))
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(define $write-char
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(lambda (c p)
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(let ([idx (port-output-index p)])
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(if ($fx< idx ($port-output-size p))
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(begin
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($string-set! ($port-output-buffer p) idx c)
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($set-port-output-index! p ($fxadd1 idx)))
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(($port-handler p) 'write-char c p)))))
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(define $read-char
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(lambda (p)
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(let ([idx ($port-input-index p)])
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(if ($fx< idx ($port-input-size p))
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(begin
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($set-port-input-index! p ($fxadd1 idx))
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($string-ref ($port-input-buffer p) idx))
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(begin
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(($port-handler p) 'read-char p))))))
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(define $peek-char
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(lambda (p)
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(let ([idx ($port-input-index p)])
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(if ($fx< idx ($port-input-size p))
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($string-ref ($port-input-buffer p) idx)
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(($port-handler p) 'peek-char p)))))
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(define $unread-char
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(lambda (c p)
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(let ([idx ($fxsub1 ($port-input-index p))])
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(if (and ($fx>= idx 0)
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($fx< idx ($port-input-size p)))
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(begin
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($set-port-input-index! p idx)
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($string-set! ($port-input-buffer p) idx c))
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(($port-handler p) 'unread-char c p)))))
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(define $reset-input-port!
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(lambda (p)
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($set-port-input-size! p 0)))
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(define $close-input-port
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(lambda (p)
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(($port-handler p) 'close-port p)))
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(define $close-output-port
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(lambda (p)
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(($port-handler p) 'close-port p)))
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(define $flush-output-port
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(lambda (p)
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(($port-handler p) 'flush-output-port p))))
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