unreadStreamChar

Function: unreadStreamChar { stream -> }

file: job.t
package: muf
status: alpha

If the job has just read a value via readStreamChar or readStreamByte, then unreadStreamChar may be used to effectively undo the read.

There is no guarantee of being able to unread more than one value deep, and the effect of calling unreadStreamChar in other contexts is undefined. (In general, however, unreadStreamChar will do either the obvious thing, or nothing.)

This function is also available under the names unreadStreamByte and unreadStreamValue, to improve code readability.

Example:

stack:
makeMessageStream --> *s*
stack:
"abc\n" *s* writeStream
stack:
*s* readStreamByte
stack: 97 #<root root>
pop pop
stack:
*s* readStreamChar
stack: 'b' #<root root>
pop pop
stack:
*s* readStreamValue
stack: 'c' "txt" #<root root>
pop pop pop
stack:
*s* unreadStreamValue
stack:
*s* readStreamValue
stack: 'c' "txt" #<root root>

See section unreadChar.

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