Class | RubyLex::BufferedReader |
In: |
parsers/parse_rb.rb
|
Parent: | Object |
Read an input stream character by character. We allow for unlimited ungetting of characters just read.
We simplify the implementation greatly by reading the entire input into a buffer initially, and then simply traversing it using pointers.
We also have to allow for the here document diversion. This little gem comes about when the lexer encounters a here document. At this point we effectively need to split the input stream into two parts: one to read the body of the here document, the other to read the rest of the input line where the here document was initially encountered. For example, we might have
do_something(<<-A, <<-B) stuff for A stuff for B
When the lexer encounters the <<A, it reads until the end of the line, and keeps it around for later. It then reads the body of the here document. Once complete, it needs to read the rest of the original line, but then skip the here document body.
line_num | [R] |
# File parsers/parse_rb.rb, line 348 348: def initialize(content) 349: if /\t/ =~ content 350: tab_width = Options.instance.tab_width 351: content = content.split(/\n/).map do |line| 352: 1 while line.gsub!(/\t+/) { ' ' * (tab_width*$&.length - $`.length % tab_width)} && $~ #` 353: line 354: end .join("\n") 355: end 356: @content = content 357: @content << "\n" unless @content[-1,1] == "\n" 358: @size = @content.size 359: @offset = 0 360: @hwm = 0 361: @line_num = 1 362: @read_back_offset = 0 363: @last_newline = 0 364: @newline_pending = false 365: end
# File parsers/parse_rb.rb, line 421 421: def divert_read_from(reserve) 422: @content[@offset, 0] = reserve 423: @size = @content.size 424: end
# File parsers/parse_rb.rb, line 402 402: def get_read 403: res = @content[@read_back_offset...@offset] 404: @read_back_offset = @offset 405: res 406: end
# File parsers/parse_rb.rb, line 371 371: def getc 372: return nil if @offset >= @size 373: ch = @content[@offset, 1] 374: 375: @offset += 1 376: @hwm = @offset if @hwm < @offset 377: 378: if @newline_pending 379: @line_num += 1 380: @last_newline = @offset - 1 381: @newline_pending = false 382: end 383: 384: if ch == "\n" 385: @newline_pending = true 386: end 387: ch 388: end
# File parsers/parse_rb.rb, line 408 408: def peek(at) 409: pos = @offset + at 410: if pos >= @size 411: nil 412: else 413: @content[pos, 1] 414: end 415: end
# File parsers/parse_rb.rb, line 417 417: def peek_equal(str) 418: @content[@offset, str.length] == str 419: end