Module: StreamParser

Defined in:
lib/stream_parser.rb,
lib/stream_parser/version.rb

Defined Under Namespace

Modules: ClassMethods, HTML Classes: SyntaxError

Constant Summary collapse

VERSION = 
'0.4'

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#match ⇒ Object

Returns the value of attribute match.



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# File 'lib/stream_parser.rb', line 18

def match
  @match
end

Class Method Details

.included(base) ⇒ Object 



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# File 'lib/stream_parser.rb', line 6

def self.included(base)
  base.extend ClassMethods
end

Instance Method Details

#current_line ⇒ Object 



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# File 'lib/stream_parser.rb', line 100

def current_line
  start = @source.rindex(/(\n|\A)/, @index-(@match&.length||0)) || 0
  start += 1 if @source[start] == "\n"

  uptop = @source.index(/(\n|\z)/, @index)
  uptop -= 1 if @source[uptop] == "\n"

  @source[start..uptop]
end

#cursor ⇒ Object 



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# File 'lib/stream_parser.rb', line 110

def cursor
  start = @source.rindex(/(\n|\A)/, @index-(@match&.length||0)) || 0
  start += 1 if @source[start] == "\n"

  uptop = @source.index(/(\n|\z)/, @index)
  uptop -= 1 if @source[uptop] == "\n"

  lineno = @source[0..start].count("\n") + 1

  output =  "#{lineno.to_s.rjust(4)}: #{@source[start..uptop]}\n     "
  output << if @match
    " #{'-'* (@index-(@match.length)-start)}#{'^'*(@match.length)}"
  else
    "^"
  end
  output
end

#eos? ⇒ Boolean

def parse

# implmentation

end

Returns:

  • (Boolean) 


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# File 'lib/stream_parser.rb', line 29

def eos?
  @index >= (@source.size - 0)
end

#forward(by = 1) ⇒ Object 



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# File 'lib/stream_parser.rb', line 65

def forward(by=1)
  @index += by
end

#gobble(r) ⇒ Object 



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# File 'lib/stream_parser.rb', line 50

def gobble(r)
  m = @source.match(r, @index)
  if m&.begin(0) == @index
    scan_until(r)
  end
end

#initialize(source) ⇒ Object 



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# File 'lib/stream_parser.rb', line 20

def initialize(source)
  @source = source
  seek(0)
end

#next?(r) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/stream_parser.rb', line 83

def next?(r)
  @source.match(r, @index)&.begin(0) == @index
end

#next_char ⇒ Object 



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# File 'lib/stream_parser.rb', line 75

def next_char
  @source[@index]
end

#next_word ⇒ Object 



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# File 'lib/stream_parser.rb', line 95

def next_word
  nw = @source.match(/\s*(\S+)/, @index)
  nw.nil? ? nil : nw[1]
end

#peek(n = 1) ⇒ Object 



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# File 'lib/stream_parser.rb', line 87

def peek(n=1)
  if n.is_a?(Regexp)
    @source.match(n, @index)
  else
    @source.slice(@index, n)
  end
end

#pre_match ⇒ Object 



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# File 'lib/stream_parser.rb', line 57

def pre_match
  @source[@old_index...(@index-(@match&.size || 0))]
end

#prev_char ⇒ Object 



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# File 'lib/stream_parser.rb', line 79

def prev_char
  @source[@index-1]
end

#quoted_value(quote_char = '"', escape_chars = ["\\"]) ⇒ Object 



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# File 'lib/stream_parser.rb', line 128

def quoted_value(quote_char = '"', escape_chars = ["\\"])
  ret_value = ""
  while scan_until(/(#{quote_char}|\Z)/)
    if match != quote_char
      raise StreamParser::SyntaxError.new("Unbalanced quotes #{quote_char}")
    elsif !escape_chars.include?(pre_match[-1])
      ret_value << pre_match
      return ret_value
    else
      ret_value << pre_match[0...-1] << match
    end
  end
end

#rewind(by = 1) ⇒ Object 



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# File 'lib/stream_parser.rb', line 61

def rewind(by=1)
  @index -= by
end

#scan_until(r) ⇒ Object 



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# File 'lib/stream_parser.rb', line 33

def scan_until(r)
  r = Regexp.new(Regexp.escape(r)) if r.is_a?(String)
  match = @source.match(r, @index)
  index = match&.begin(0)
  
  if match
    @match = match.to_s
    @old_index = @index
    @index = index + @match.size
  else
    @match = nil
    @old_index = @index
    @index = @source.size
  end
  match
end

#seek(pos) ⇒ Object 



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# File 'lib/stream_parser.rb', line 69

def seek(pos)
  @old_index = nil
  @match = nil
  @index = pos
end