| org.antlr.runtime.IntStream
| IntStream | | public interface IntStream (Code) | | A simple stream of integers used when all I care about is the char
or token type sequence (such as interpretation).
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| Method Summary | |
| int | LA(int i)
Get int at current input pointer + i ahead where i=1 is next int.
Negative indexes are allowed. | | void | consume()
| | int | index()
Return the current input symbol index 0..n where n indicates the
last symbol has been read. | | int | mark()
Tell the stream to start buffering if it hasn't already. | | void | release(int marker)
You may want to commit to a backtrack but don't want to force the
stream to keep bookkeeping objects around for a marker that is
no longer necessary. | | void | rewind(int marker)
Reset the stream so that next call to index would return marker.
The marker will usually be index() but it doesn't have to be. | | void | rewind()
Rewind to the input position of the last marker.
Used currently only after a cyclic DFA and just
before starting a sem/syn predicate to get the
input position back to the start of the decision.
Do not "pop" the marker off the state. | | void | seek(int index)
Set the input cursor to the position indicated by index. | | int | size()
Only makes sense for streams that buffer everything up probably, but
might be useful to display the entire stream or for testing. |
| LA | | int LA(int i)(Code) | | Get int at current input pointer + i ahead where i=1 is next int.
Negative indexes are allowed. LA(-1) is previous token (token
just matched). LA(-i) where i is before first token should
yield -1, invalid char / EOF.
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| index | | int index()(Code) | | Return the current input symbol index 0..n where n indicates the
last symbol has been read. The index is the symbol about to be
read not the most recently read symbol.
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| mark | | int mark()(Code) | | Tell the stream to start buffering if it hasn't already. Return
current input position, index(), or some other marker so that
when passed to rewind() you get back to the same spot.
rewind(mark()) should not affect the input cursor. The Lexer
track line/col info as well as input index so its markers are
not pure input indexes. Same for tree node streams.
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| release | | void release(int marker)(Code) | | You may want to commit to a backtrack but don't want to force the
stream to keep bookkeeping objects around for a marker that is
no longer necessary. This will have the same behavior as
rewind() except it releases resources without the backward seek.
This must throw away resources for all markers back to the marker
argument. So if you're nested 5 levels of mark(), and then release(2)
you have to release resources for depths 2..5.
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| rewind | | void rewind(int marker)(Code) | | Reset the stream so that next call to index would return marker.
The marker will usually be index() but it doesn't have to be. It's
just a marker to indicate what state the stream was in. This is
essentially calling release() and seek(). If there are markers
created after this marker argument, this routine must unroll them
like a stack. Assume the state the stream was in when this marker
was created.
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| rewind | | void rewind()(Code) | | Rewind to the input position of the last marker.
Used currently only after a cyclic DFA and just
before starting a sem/syn predicate to get the
input position back to the start of the decision.
Do not "pop" the marker off the state. mark(i)
and rewind(i) should balance still. It is
like invoking rewind(last marker) but it should not "pop"
the marker off. It's like seek(last marker's input position).
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| seek | | void seek(int index)(Code) | | Set the input cursor to the position indicated by index. This is
normally used to seek ahead in the input stream. No buffering is
required to do this unless you know your stream will use seek to
move backwards such as when backtracking.
This is different from rewind in its multi-directional
requirement and in that its argument is strictly an input cursor (index).
For char streams, seeking forward must update the stream state such
as line number. For seeking backwards, you will be presumably
backtracking using the mark/rewind mechanism that restores state and
so this method does not need to update state when seeking backwards.
Currently, this method is only used for efficient backtracking using
memoization, but in the future it may be used for incremental parsing.
The index is 0..n-1. A seek to position i means that LA(1) will
return the ith symbol. So, seeking to 0 means LA(1) will return the
first element in the stream.
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| size | | int size()(Code) | | Only makes sense for streams that buffer everything up probably, but
might be useful to display the entire stream or for testing. This
value includes a single EOF.
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