================================================================================
If, elif and else directives
================================================================================

#if WIN32
  string os = "Win32";
#elif MACOS
  string os = "MacOS";
#else
  string os = "Unknown";
#endif

--------------------------------------------------------------------------------

(compilation_unit
  (if_directive
    (identifier))
  (global_statement
    (local_declaration_statement
      (variable_declaration
        type: (predefined_type)
        (variable_declarator
          name: (identifier)
          (equals_value_clause
            (string_literal
              (string_literal_fragment)))))))
  (elif_directive
    (identifier))
  (global_statement
    (local_declaration_statement
      (variable_declaration
        type: (predefined_type)
        (variable_declarator
          name: (identifier)
          (equals_value_clause
            (string_literal
              (string_literal_fragment)))))))
  (else_directive)
  (global_statement
    (local_declaration_statement
      (variable_declaration
        type: (predefined_type)
        (variable_declarator
          name: (identifier)
          (equals_value_clause
            (string_literal
              (string_literal_fragment)))))))
  (endif_directive))

================================================================================
Complex if conditions
================================================================================
#if !MACOS
#if WIN32==true
#if !MACOS!=false
#if A && B || C
#if (A)
#if (A || B)
#if (A && B) || C

--------------------------------------------------------------------------------

(compilation_unit
  (if_directive
    (prefix_unary_expression
      argument: (identifier)))
  (if_directive
    (binary_expression
      left: (identifier)
      right: (boolean_literal)))
  (if_directive
    (binary_expression
      left: (prefix_unary_expression
        argument: (identifier))
      right: (boolean_literal)))
  (if_directive
    (binary_expression
      left: (binary_expression
        left: (identifier)
        right: (identifier))
      right: (identifier)))
  (if_directive
    (parenthesized_expression
      (identifier)))
  (if_directive
    (parenthesized_expression
      (binary_expression
        left: (identifier)
        right: (identifier))))
  (if_directive
    (binary_expression
      left: (parenthesized_expression
        (binary_expression
          left: (identifier)
          right: (identifier)))
      right: (identifier))))

================================================================================
Region directives
================================================================================

#region Here, there, everywhere

// something fast

#endregion

--------------------------------------------------------------------------------

(compilation_unit
  (region_directive
    (preproc_message))
  (comment)
  (endregion_directive))

================================================================================
Define and undefine directives
================================================================================

#define SOMETHING
#undef BAD

--------------------------------------------------------------------------------

(compilation_unit
  (define_directive
    (identifier))
  (undef_directive
    (identifier)))

================================================================================
Warning and error directives
================================================================================

class Of1879 {
#warning This class is bad.
#error Okay, just stop.
}

--------------------------------------------------------------------------------

(compilation_unit
  (class_declaration
    name: (identifier)
    body: (declaration_list
      (warning_directive
        (preproc_message))
      (error_directive
        (preproc_message)))))

================================================================================
Line directives
================================================================================

class Of1879 {
  void AMethod() {
#line 2001 "A Space" // Comment
#line hidden
#line default
#line (1, 1) - (1, 3) 1 "a.cs"
#line (2, 1) - (2, 3) "a.cs"
  }
}

--------------------------------------------------------------------------------

(compilation_unit
  (class_declaration
    name: (identifier)
    body: (declaration_list
      (method_declaration
        type: (predefined_type)
        name: (identifier)
        parameters: (parameter_list)
        body: (block
          (line_directive
            (preproc_integer_literal)
            (preproc_string_literal))
          (comment)
          (line_directive)
          (line_directive)
          (line_directive
            (preproc_integer_literal)
            (preproc_integer_literal)
            (preproc_integer_literal)
            (preproc_integer_literal)
            (preproc_integer_literal)
            (preproc_string_literal))
          (line_directive
            (preproc_integer_literal)
            (preproc_integer_literal)
            (preproc_integer_literal)
            (preproc_integer_literal)
            (preproc_string_literal)))))))

================================================================================
Spaces in directives
================================================================================

class Of1879 {
  void AMethod() {
# line 2001 "A Space"
#  line hidden
#    line default
  }
}

--------------------------------------------------------------------------------

(compilation_unit
  (class_declaration
    name: (identifier)
    body: (declaration_list
      (method_declaration
        type: (predefined_type)
        name: (identifier)
        parameters: (parameter_list)
        body: (block
          (line_directive
            (preproc_integer_literal)
            (preproc_string_literal))
          (line_directive)
          (line_directive))))))

================================================================================
Pragmas
================================================================================

#pragma warning disable 660,661,nullable

--------------------------------------------------------------------------------

(compilation_unit
  (pragma_directive
    (integer_literal)
    (integer_literal)
    (identifier)))

================================================================================
Directives not in strings or comments
================================================================================

class Of1879 {
  void AMethod() {
    var s = @"Only a string
    #if NOPE
";
    /* Only a comment
    #if NOPE
    */
  }
}

--------------------------------------------------------------------------------

(compilation_unit
  (class_declaration
    name: (identifier)
    body: (declaration_list
      (method_declaration
        type: (predefined_type)
        name: (identifier)
        parameters: (parameter_list)
        body: (block
          (local_declaration_statement
            (variable_declaration
              type: (implicit_type)
              (variable_declarator
                name: (identifier)
                (equals_value_clause
                  (verbatim_string_literal)))))
          (comment))))))

================================================================================
Reference (r) directive
================================================================================

#r "Microsoft.WindowsAzure.Storage"

--------------------------------------------------------------------------------

(compilation_unit
  (reference_directive
    (preproc_string_literal)))

================================================================================
Load directive
================================================================================

#load "mylogger.csx"

--------------------------------------------------------------------------------

(compilation_unit
  (load_directive
    (preproc_string_literal)))

================================================================================
Shebang directive
================================================================================

#!/usr/bin/env scriptcs

--------------------------------------------------------------------------------

(compilation_unit
  (shebang_directive))