nltk.app.chartparser_app

module documentation
(source)

A graphical tool for exploring chart parsing.

Chart parsing is a flexible parsing algorithm that uses a data structure called a "chart" to record hypotheses about syntactic constituents. Each hypothesis is represented by a single "edge" on the chart. A set of "chart rules" determine when new edges can be added to the chart. This set of rules controls the overall behavior of the parser (e.g. whether it parses top-down or bottom-up).

The chart parsing tool demonstrates the process of parsing a single sentence, with a given grammar and lexicon. Its display is divided into three sections: the bottom section displays the chart; the middle section displays the sentence; and the top section displays the partial syntax tree corresponding to the selected edge. Buttons along the bottom of the window are used to control the execution of the algorithm.

The chart parsing tool allows for flexible control of the parsing algorithm. At each step of the algorithm, you can select which rule or strategy you wish to apply. This allows you to experiment with mixing different strategies (e.g. top-down and bottom-up). You can exercise fine-grained control over the algorithm by selecting which edge you wish to apply a rule to.

Class BottomUpEdgeRule Undocumented
Class BottomUpLeftCornerEdgeRule Undocumented
Class ChartComparer No summary
Class ChartMatrixView A view of a chart that displays the contents of the corresponding matrix.
Class ChartParserApp No class docstring; 0/19 instance variable, 0/10 constant, 4/46 methods documented
Class ChartResultsView Undocumented
Class ChartView A component for viewing charts. This is used by ChartParserApp to allow students to interactively experiment with various chart parsing techniques. It is also used by Chart.draw().
Class EdgeList Undocumented
Class EdgeRule To create an edge rule, make an empty base class that uses EdgeRule as the first base class, and the basic rule as the second base class. (Order matters!)
Class FundamentalEdgeRule Undocumented
Class TopDownPredictEdgeRule Undocumented
Function app Undocumented
def app(): (source) ΒΆ

Undocumented