Syntactic Processing
The initial phase of natural language processing is syntactic processing. Sentences in syntactic processing are examined for grammar errors. It is necessary to understand grammar rules and parsing strategies to carry out syntactic processing.
Grammar is the official list of rules that are permitted in a language, and parsing is the process of dissecting a sentence to ascertain its structure by grammar. Parsing is used in syntactic processing. Basic sentence syntactic structures are generated by the parser generator. This parser applies some structural processing to the input by using grammatical information.
Therefore, a parser is a software component that is designed to take in input data and, after verifying that the grammar and syntax are correct, provide a structural representation of the input.
The Basic Parsing Technique is shown below
The Parser is a computer, which accepts the Natural language as input and generates output structures.
Two Basic Techniques are:
- Top Down Parsing
- Bottom-Up Parsing
Top Down Parsing
The top-down parsing algorithm uses a basic parsing algorithm. Grammar rules are applied to a starting symbol in top-down parsing until they produce terminal symbols, which are then found in the object sentence.
In this type of parsing, the parser attempts to convert the start symbol to the input after beginning to build the parse tree from the start symbol. Recursive procedures are used in the most popular type of top-down parsing to process the input.
Example: S -----> E
Where S denotes the Starting Symbol and E denotes the endpoint.
E-----> E+E / E*E /e/f/g.
Input: e + f * g
Structure:
Bottom To Up Parsing
Compared to top-down parsing, bottom-up parsing is more flexible. When using bottom-up parsing, we begin with the sentence and attempt to apply the production rules in reverse until we reach the grammar's start symbol. The sentence "Raju ate an apple" is parsed from the bottom up.
Example:
