py-token-stream
Take a list of tokens and produce a more useful API to give to a parser.
Inspired by pugjs/token-stream.
Installation
pip install py-token-stream
Usage
from py_token_stream import TokenStream
stream = TokenStream(['a', 'b', 'c', 'd'])
stream.peek() # 'a'
stream.advance() # 'a'
stream.lookahead(0) # 'b'
stream.lookahead(1) # 'c'
stream.advance() # 'b'
stream.defer('z')
stream.peek() # 'z'
stream.advance() # 'z'
stream.advance() # 'c'
stream.advance() # 'd'
stream.advance() # IndexError!
API
TokenStream.peek()
Gets and returns the next item in the stream without advancing the stream's position.
TokenStream.advance()
Returns the next item in the stream and advances the stream by one item.
TokenStream.lookahead(index)
Return the item at index
position from the start of the stream, but don't advance the stream. TokenStream.lookahead(0)
is equivalent to TokenStream.peek()
.
TokenStream.defer(token)
Put a token on the start of the stream (useful if you need to back track after calling advance).
License
MIT