Module: Lexer

Included in:
ReDuxml::Parser
Defined in:
lib/re_duxml/evaluate/lexer.rb

Constant Summary collapse

TOKEN_TYPES = 
{
    string:   /STRING[\d]+/,
    function: /log|exp|sqrt/,
    bool:     /true|false/,
    param:    Regexp.identifier,
    num:      /\d+/,
    grouping: /[\(\):,]/
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#input ⇒ Object

Returns the value of attribute input.



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# File 'lib/re_duxml/evaluate/lexer.rb', line 10

def input
  @input
end

#string_hash ⇒ Object (readonly)

Returns the value of attribute string_hash.



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# File 'lib/re_duxml/evaluate/lexer.rb', line 9

def string_hash
  @string_hash
end

#tokens ⇒ Object

Returns the value of attribute tokens.



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# File 'lib/re_duxml/evaluate/lexer.rb', line 10

def tokens
  @tokens
end

Instance Method Details

#lex(expr) ⇒ Object 



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# File 'lib/re_duxml/evaluate/lexer.rb', line 23

def lex(expr)
  @input = tag_strings(expr).split(/\b/).reverse.collect do |s| s.strip end
  @tokens = []
  while (sub_str = input.pop) do
    type = get_type sub_str
    value = formatted_value(sub_str, type)
    tokens << (@last_token = Struct::Token.new(type, value)) unless value.nil?
  end
  @last_token = nil
  tokens
end