Lexer
=====

.. cpp:class:: numpy::Lexer

   numpy C++ class.

Example
-------

.. code-block:: cpp

   #include <numpy/np_ndarray.h>
   using namespace numpy;

   // Use Lexer
   Lexer obj;
   // ... operations ...

Other Methods
-------------

.. list-table::
   :widths: 40 20 15 25
   :header-rows: 1

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``void advance()``
     - void
     - df_query.h:89
     - 
   * - ``char current() const``
     - char
     - df_query.h:80
     - 
   * - ``explicit Lexer(std::string input) : input\_(std::move(input))``
     - explicit Lexer(std::string input) :
     - df_query.h:164
     - 
   * - ``Token next_token()``
     - Token
     - df_query.h:166
     - 
   * - ``char peek(size_t ahead = 1) const``
     - char
     - df_query.h:84
     - 
   * - ``Token read_identifier()``
     - Token
     - df_query.h:99
     - 
   * - ``Token read_number()``
     - Token
     - df_query.h:115
     - 
   * - ``Token read_string(char quote)``
     - Token
     - df_query.h:141
     - 
   * - ``void skip_whitespace()``
     - void
     - df_query.h:93
     - :ref:`View <example-lexer-skip_whitespace-0>`
   * - ``Token tok(TokenType::NUMBER, num)``
     - Token
     - df_query.h:136
     - 


Code Examples
-------------

The following examples are extracted from the test suite.

.. _example-lexer-skip_whitespace-0:

.. dropdown:: skip_whitespace (np_test_5_all.cpp:976)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 966
      :emphasize-lines: 11

            assert_condition(type1 == "int", "Failed to detect int type");
            assert_condition(type2 == "float", "Failed to detect float type");
            assert_condition(type3 == "string", "Failed to detect string type");
      
            // std::cout << "  Tested value type detection" << std::endl;
      
            std::cout << " -> tests passed" << std::endl;
          }
      
          void np_test_io_skip_whitespace() {
            std::cout << "========= skip_whitespace() utility ============================";
      
            // Test whitespace skipping
            std::string test = "   \t\n  text";
            size_t pos = 0;
      
            // Skip whitespace
            while (pos < test.size() && std::isspace(test[pos])) {
              ++pos;
            }