Function parse_csv 

pub fn parse_csv(content: &str) -> String

Parses CSV data and returns it as a JSON string.

Parses the CSV content and identifies numeric columns. Returns a JSON object with headers, data rows, and a list of numeric column names.

Arguments

• content - CSV content as a string

Returns

JSON string with structure:

{
  "headers": ["col1", "col2", ...],
  "data": [{"col1": 1.0, "col2": "text"}, ...],
  "numeric_columns": ["col1", ...]
}

Errors

Returns a JSON error object if parsing fails or domain check fails.