How to Build a Parser: Recursive Descent, Top-Down Techniques, and Parsing Nested Key-Value Pairs.

How to Create a Parser: A Comprehensive Guide

Parsing involves extracting meaningful information from raw text or data. To create a parser, there are several approaches and tools available.

Recursive Descent Parsing

Recursive descent parsing splits the input into smaller chunks and calls itself recursively to handle each piece. This approach is straightforward and adaptable to various grammar rules.

Top-Down Parsing

Top-down parsing begins by recognizing the highest-level structure and progressively refines it into smaller units. Tools like ANTLR (ANother Tool for Language Recognition) or Bison (Bison, Yacc, etc. Improved for Superior Novices) make top-down parsing more efficient.

Specific Example: Parsing Nested Key-Value Pairs

To parse a sample string like:

{key1 = value1 | key2 = {key3 = value3} | key4 = {key5 = { key6 = value6 }}}

into a nested map like:

map[key1] = value1
map[key2] = (map[key3] = value3)
map[key4] = (map[key5] = (map[key6] = value6))

Consider using a library like github.com/alecthomas/goparser or github.com/gobuffalo/pop that offers built-in parsing capabilities. Alternatively, you can implement your own grammar using tools like Jison or Lemon Parser Generator.

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