Class: RubyLex::BufferedReader
- Inherits:
-
Object
- Object
- RubyLex::BufferedReader
- Defined in:
- lib/rdoc/parsers/parse_rb.rb
Overview
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
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.
Instance Attribute Summary collapse
-
#line_num ⇒ Object
readonly
Returns the value of attribute line_num.
Instance Method Summary collapse
- #column ⇒ Object
- #divert_read_from(reserve) ⇒ Object
- #get_read ⇒ Object
- #getc ⇒ Object
- #getc_already_read ⇒ Object
-
#initialize(content, options) ⇒ BufferedReader
constructor
A new instance of BufferedReader.
- #peek(at) ⇒ Object
- #peek_equal(str) ⇒ Object
- #ungetc(ch) ⇒ Object
Constructor Details
#initialize(content, options) ⇒ BufferedReader
Returns a new instance of BufferedReader.
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# File 'lib/rdoc/parsers/parse_rb.rb', line 347 def initialize(content, ) @options = if /\t/ =~ content tab_width = @options.tab_width content = content.split(/\n/).map do |line| 1 while line.gsub!(/\t+/) { ' ' * (tab_width*$&.length - $`.length % tab_width)} && $~ #` line end .join("\n") end @content = content @content << "\n" unless @content[-1,1] == "\n" @size = @content.size @offset = 0 @hwm = 0 @line_num = 1 @read_back_offset = 0 @last_newline = 0 @newline_pending = false end |
Instance Attribute Details
#line_num ⇒ Object (readonly)
Returns the value of attribute line_num.
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# File 'lib/rdoc/parsers/parse_rb.rb', line 345 def line_num @line_num end |
Instance Method Details
#column ⇒ Object
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# File 'lib/rdoc/parsers/parse_rb.rb', line 368 def column @offset - @last_newline end |
#divert_read_from(reserve) ⇒ Object
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# File 'lib/rdoc/parsers/parse_rb.rb', line 422 def divert_read_from(reserve) @content[@offset, 0] = reserve @size = @content.size end |
#get_read ⇒ Object
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# File 'lib/rdoc/parsers/parse_rb.rb', line 403 def get_read res = @content[@read_back_offset...@offset] @read_back_offset = @offset res end |
#getc ⇒ Object
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# File 'lib/rdoc/parsers/parse_rb.rb', line 372 def getc return nil if @offset >= @size ch = @content[@offset, 1] @offset += 1 @hwm = @offset if @hwm < @offset if @newline_pending @line_num += 1 @last_newline = @offset - 1 @newline_pending = false end if ch == "\n" @newline_pending = true end ch end |
#getc_already_read ⇒ Object
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# File 'lib/rdoc/parsers/parse_rb.rb', line 391 def getc_already_read getc end |
#peek(at) ⇒ Object
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# File 'lib/rdoc/parsers/parse_rb.rb', line 409 def peek(at) pos = @offset + at if pos >= @size nil else @content[pos, 1] end end |
#peek_equal(str) ⇒ Object
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# File 'lib/rdoc/parsers/parse_rb.rb', line 418 def peek_equal(str) @content[@offset, str.length] == str end |
#ungetc(ch) ⇒ Object
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# File 'lib/rdoc/parsers/parse_rb.rb', line 395 def ungetc(ch) raise "unget past beginning of file" if @offset <= 0 @offset -= 1 if @content[@offset] == ?\n @newline_pending = false end end |