How can PHP convert numerical words to integers using a language parser approach?

Converting Words to Numbers in PHP: Exploring the Language Parser Approach

For the problem of converting numerical words to integers, finding suitable libraries or functions can be challenging. However, there exists an interesting algorithm that can be implemented as a pseudo-code or parser.

The algorithm targets two key tasks: tokenizing the numerical words and applying grammar rules. This process functions as a parser for a limited language.

Tokenizing

The necessary tokens include:

• POWER: thousand, million, billion
• HUNDRED: hundred
• TEN: twenty, thirty... ninety
• UNIT: one, two, three, ... nine,
• SPECIAL: ten, eleven, twelve, ... nineteen

The algorithm moves from right to left and grabs all tokens until it encounters a POWER or the complete string.

Pattern Parsing

Tokens after the stop point are parsed for specific patterns, including:

• SPECIAL
• TEN
• UNIT
• TEN UNIT
• UNIT HUNDRED
• UNIT HUNDRED SPECIAL
• UNIT HUNDRED TEN
• UNIT HUNDRED UNIT
• UNIT HUNDRED TEN UNIT

Conversion Process

Once the algorithm reaches the complete string, the conversion is done. If it stops at a POWER, the process repeats recursively until the end of the string or a higher POWER is reached. Each iteration provides the last three digits of the converted number.

This approach offers a comprehensive solution for converting numerical words to integers and highlights the power of parsing techniques in natural language processing.

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