Class: ZIG::Parser

Inherits:
Object
  • Object
show all
Defined in:
lib/zig/parser.rb

Constant Summary collapse

INDENT = 
2
FULL_LINE = 
/^( *)(.*)$/
KEY_VALUE = 
/^([^:]+):(.*)$/
STRING = 
/^'(.*)'$/
INTEGER = 
/^-?\d+$/
FLOAT = 
/^-?\d+\.\d+([eE][+-]?\d+)?$/

Class Method Summary collapse

Class Method Details

.parse_document(lines) ⇒ Object

Raises:



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# File 'lib/zig/parser.rb', line 50

def self.parse_document(lines)
  raise ZIG::SyntaxError, "cannot parse empty document" if lines.empty?
  lines.next while lines.current[0] == '#'
  start = lines.current
  lines.next
  return parse_value(0, lines, start)
end

.parse_object(indent, lines, object) ⇒ Object 



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# File 'lib/zig/parser.rb', line 11

def self.parse_object(indent, lines, object)
  loop do
    return object if lines.empty?
    spaces, value = lines.current.scan(FULL_LINE).flatten
    return object if spaces.size < indent
    raise ZIG::SyntaxError, "[line #{lines.num}] illegal indent" if spaces.size > indent
    lines.next
    if object.is_a?(String)
      object << "\n" unless object.empty?
      object << value
    elsif object.is_a?(Array)
      next if value[0] == '#'
      object << parse_value(indent, lines, value)
    else
      next if value[0] == '#'
      key, value = value.scan(KEY_VALUE).flatten
      raise ZIG::SyntaxError, "[line #{lines.num - 1}] missing key" if key.nil?
      object[key.strip.to_sym] = parse_value(indent, lines, value)
    end
  end
end

.parse_value(indent, lines, text) ⇒ Object 



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# File 'lib/zig/parser.rb', line 33

def self.parse_value(indent, lines, text)
  text = text.strip
  case text
  when 'nil'   then nil
  when 'true'  then true
  when 'false' then false
  when '{'     then parse_object(indent + INDENT, lines, {})
  when '['     then parse_object(indent + INDENT, lines, [])
  when '"'     then parse_object(indent + INDENT, lines, "")
  when STRING  then $1
  when INTEGER then text.to_i
  when FLOAT   then text.to_f
  else
    raise ZIG::SyntaxError, "[line #{lines.num}] illegal value: #{text}"
  end
end