lib/includable-lexer.cc

   1 /*
   2   includable-lexer.cc -- implement Includable_lexer
   3
   4   source file of the LilyPond music typesetter
   5
   6   (c) 1997 Han-Wen Nienhuys <hanwen@stack.nl>
   7 */
   8 #include "includable-lexer.hh"
   9 #include "source-file.hh"
  10 #include "source.hh"
  11
  12 Includable_lexer::Includable_lexer()
  13 {
  14     yy_current_buffer = 0;
  15 }
  16
  17 /** set the  new input to s, remember old file.
  18 */
  19 void
  20 Includable_lexer::new_input(String s, Sources  * global_sources)
  21 {
  22     Source_file * sl = global_sources->get_file_l(s);
  23     if (!sl) {
  24         LexerError("Can't find file `" + s+ "'");
  25         return;
  26     }
  27
  28
  29     char_count_stack_.push(0);
  30     if (yy_current_buffer)
  31         state_stack_.push(yy_current_buffer);
  32     cout << "[" << s<<flush;
  33     include_stack_.push(sl);
  34
  35     // ugh. We'd want to create a buffer from the bytes directly.
  36     yy_switch_to_buffer(yy_create_buffer( sl->istream_l(), sl->length_off() ));
  37 }
  38
  39 /** pop the inputstack.  conceptually this is a destructor, but it
  40   does not destruct the Source_file that Includable_lexer::new_input creates.  */
  41 bool
  42 Includable_lexer::close_input()
  43 {
  44     include_stack_.pop();
  45     char_count_stack_.pop();
  46     cout << "]"<<flush;
  47     yy_delete_buffer(yy_current_buffer );
  48     yy_current_buffer = 0;
  49     if (state_stack_.empty()) {
  50         return false;
  51     }else {
  52         yy_switch_to_buffer(state_stack_.pop());
  53         return true;
  54     }
  55 }
  56
  57 char const*
  58 Includable_lexer::here_ch_C()
  59 {
  60     if (include_stack_.empty())
  61         return 0;
  62     return include_stack_.top()->ch_C() + char_count_stack_.top();
  63 }
  64
  65 Includable_lexer::~Includable_lexer()
  66 {
  67     while (!include_stack_.empty()) {
  68         close_input();
  69     };
  70 }
  71 /**
  72   Since we don't create the buffer state from the bytes directly, we
  73   don't know about the location of the lexer. Add this as a
  74   YY_USER_ACTION */
  75 void
  76 Includable_lexer::add_lexed_char(int count)
  77 {
  78     char_count_stack_.top() += count;
  79 }
  80
  81 Source_file*
  82 Includable_lexer::source_file_l()const
  83 {
  84     if (include_stack_.empty())
  85         return 0;
  86     else
  87         return include_stack_.top();
  88 }