diff options
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 15 |
1 files changed, 15 insertions, 0 deletions
@@ -10494,6 +10494,16 @@ Some streams do not support these operations; some support only one of them. In general, if a stream supports get-char, it supports unget-char, and likewise for get-byte and unget-byte. +Space is available for only one character or byte of pushback. + +Pushing both a byte and a character, in either order, is also unsupported. +Pushing a byte and then reading a character, or pushing a character and +reading a byte, are also unsupported mixtures of operations. + +If the stream is binary, then pushing back a byte decrements its position, +except if the position is already zero. At that point, the position becomes +indeterminate. + .SS Functions put-string, put-line, put-char and put-byte .TP @@ -10570,6 +10580,11 @@ seek-stream returns the current absolute position within the stream, if it can successfully obtain it. Otherwise, it returns t if it is successful. +If a character has been successfully put back into a text stream with +unget-char and is still pending, then the position value is unspecified. If a +byte has been put back into a binary stream with unget-byte, and the previous +position wasn't zero, then the position is decremented by one. + On failure, it throws an exception of type stream-error. .SS Functions stream-get-prop and stream-set-prop |