basic interfaces IntStream +- CharStream \- TokenStream More...
Public Member Functions | |
| def | consume |
| def | getSourceName |
| def | index |
| def | LA |
| def | mark |
| def | release |
| def | rewind |
| def | seek |
| def | size |
Detailed Description
basic interfaces IntStream +- CharStream \- TokenStream
subclasses must implemented all methods
@brief Base interface for streams of integer values. A simple stream of integers used when all I care about is the char or token type sequence (such as interpretation).
Definition at line 51 of file streams.py.
Member Function Documentation
Reimplemented in rve_interface_gen.antlr3.streams.CommonTokenStream, and rve_interface_gen.antlr3.streams.ANTLRStringStream.
Definition at line 59 of file streams.py.
Where are you getting symbols from? Normally, implementations will pass the buck all the way to the lexer who can ask its input stream for the file name or whatever.
Reimplemented in rve_interface_gen.antlr3.streams.CommonTokenStream, rve_interface_gen.antlr3.streams.ANTLRFileStream, and rve_interface_gen.antlr3.streams.ANTLRStringStream.
Definition at line 172 of file streams.py.
| def rve_interface_gen.antlr3.streams.IntStream.index | ( | self | ) |
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.
Reimplemented in rve_interface_gen.antlr3.streams.CommonTokenStream, and rve_interface_gen.antlr3.streams.ANTLRStringStream.
Definition at line 87 of file streams.py.
| def rve_interface_gen.antlr3.streams.IntStream.LA | ( | self, | |
| i | |||
| ) |
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.
Reimplemented in rve_interface_gen.antlr3.streams.CommonTokenStream, and rve_interface_gen.antlr3.streams.ANTLRStringStream.
Definition at line 63 of file streams.py.
| def rve_interface_gen.antlr3.streams.IntStream.mark | ( | self | ) |
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.
Reimplemented in rve_interface_gen.antlr3.streams.CommonTokenStream, and rve_interface_gen.antlr3.streams.ANTLRStringStream.
Definition at line 74 of file streams.py.
| def rve_interface_gen.antlr3.streams.IntStream.release | ( | self, | |
marker = None |
|||
| ) |
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.
Reimplemented in rve_interface_gen.antlr3.streams.CommonTokenStream, and rve_interface_gen.antlr3.streams.ANTLRStringStream.
Definition at line 121 of file streams.py.
| def rve_interface_gen.antlr3.streams.IntStream.rewind | ( | self, | |
marker = None |
|||
| ) |
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. If marker is None: 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).
Reimplemented in rve_interface_gen.antlr3.streams.CommonTokenStream, and rve_interface_gen.antlr3.streams.ANTLRStringStream.
Definition at line 97 of file streams.py.
| def rve_interface_gen.antlr3.streams.IntStream.seek | ( | self, | |
| index | |||
| ) |
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.
Reimplemented in rve_interface_gen.antlr3.streams.CommonTokenStream, and rve_interface_gen.antlr3.streams.ANTLRStringStream.
Definition at line 135 of file streams.py.
| def rve_interface_gen.antlr3.streams.IntStream.size | ( | self | ) |
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.
Reimplemented in rve_interface_gen.antlr3.streams.CommonTokenStream, and rve_interface_gen.antlr3.streams.ANTLRStringStream.
Definition at line 162 of file streams.py.
The documentation for this class was generated from the following file: