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ANSI Common Lisp  21 Streams 21.2 Dictionary of Streams
| 21.2.24 read-sequence |
Function |
- Syntax:
-
read-sequence
sequence stream &key start end
 position
sequence - a sequence.
stream - an input stream.
start, end - bounding index designators of
sequence. The defaults for start and end are 0 and nil, respectively.
position - an integer greater than or equal to zero, and
less than or equal to the length of the sequence.
- Description:
-
Destructively modifies sequence by replacing the elements
of sequence bounded by start and end with
elements read from stream.
Sequence is destructively modified by copying successive
elements into it from stream. If the end of file for
stream is reached before copying all elements of the
subsequence, then the extra elements near the end of sequence
are not updated.
Position is the index of the first element of sequence
that was not updated, which might be less than end because the
end of file was reached.
- Examples:
-
(defvar *data* (make-array 15 :initial-element nil))
(values (read-sequence *data* (make-string-input-stream "test string")) *data*)
11, #(#\t #\e #\s #\t #\Space #\s #\t #\r #\i #\n #\g NIL NIL NIL NIL)
- Side Effects:
-
Modifies stream and sequence.
- Exceptional Situations:
-
Should be prepared to signal an error of type type-error if sequence is not a proper sequence.
Should signal an error of type type-error if start is not a non-negative integer.
Should signal an error of type type-error if end is not a non-negative integer or nil.
Might signal an error of type type-error if an element read from
the stream is not a member of the element type of the
sequence.
- See Also:
-
Section 3.2.1 Compiler Terminology,
write-sequence,
read-line
- Notes:
-
read-sequence is identical in effect to iterating over the indicated
subsequence and reading one element at a time from stream and
storing it into sequence, but may be more efficient than the
equivalent loop. An efficient implementation is more likely to exist
for the case where the sequence is a vector with the same
element type as the stream.
- Allegro CL Implementation Details:
-
None.
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