Class: WordGenerator

Inherits:
Object
  • Object
show all
Defined in:
lib/conlang/wordgenerator.rb

Overview

This Ruby class generates random words using prabability-weighted symbols, and grammar rules from a given *.lang file as input.

Instance Method Summary collapse

Constructor Details

#initialize(file) ⇒ WordGenerator

Constructor



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# File 'lib/conlang/wordgenerator.rb', line 11

def initialize(file)
  # Check file extension.

  unless file.match(/.*\.lang/)
    raise LangFileIOError,
          "Given file, \"#{file}\", is not a .lang file." 
  end

  # Check if files exist

  unless File.exist?(file)
    raise LangFileIOError,
          "File \"#{file}\" was not found." 
  end

  #   #   #   #   #   #   #   #   #


  # Input filename

  @lang_file = file

  # Bindings for SymbolSets and a variable 

  # to save the grammatical expression string.

  @bindings = {}
  @full_expression = ""

  # Bindings for replacements

  @replacements = {}

  # Parse .lang file

  parse_lang_file

  # Parse and evaluate grammatical expression

  eval_expression
end

Instance Method Details

#apply_replacements(word) ⇒ Object

Apply replacements to words



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# File 'lib/conlang/wordgenerator.rb', line 125

def apply_replacements(word)
  @replacements.each do |pattern, target|
    word.gsub!(pattern, target)
  end
  
  word
end

#eval_expression ⇒ Object

This method evaluates the grammatical expression and then generate random words.



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# File 'lib/conlang/wordgenerator.rb', line 106

def eval_expression
  @evaluated_expression =
     ConlangWordGenerator::run_expression(@full_expression, @bindings)
end

#get_words(qty = 30) ⇒ Object

This method generates words



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# File 'lib/conlang/wordgenerator.rb', line 112

def get_words(qty = 30)
  raise "Error on quantity of words." if qty < 1

  words = []

  qty.times do
    words += [apply_replacements(@evaluated_expression.sample)]
  end 

  words
end

#parse_lang_file ⇒ Object

This method reads a .lang file to parse it. It parses the symbols and then copies the full grammatical expression to evaluate it later.



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# File 'lib/conlang/wordgenerator.rb', line 47

def parse_lang_file
  # Open .lang file and parse it, then copy 

  # its full grammatical expression.

  File.open(@lang_file, "r:UTF-8") do |file|
    lines_count = 1
    current = :none

    # Evaluating lines

    while (line = file.gets)
      # Parsing .lang file

      case line
      when /(^\s*$)|(^\s*#.*$)/
        # Ignore blank lines or comments

        
      when /^\s*symbols\s*for\s*(\w*)?\s*(\w+)\s*:\s*(#.*)?$/
        # Create new symbol set

        captured = line.scan(/\s*(\w+)\s*:/)
        current_binding = captured[0][0]
        @bindings[current_binding] = ConlangWordGenerator::SymbolSet.new
        current = :symbols

      when /^\s*expression\s*:\s*(#.*)?$/
        # Start of grammatical expression

        current = :expression

      when /^\s*replacements\s*:\s*(#.*)?$/
        # Start of list of replacements

        current = :replacements

      when /^\s*(\S+)\s*[:=]\s*(\S+)\s*(#.*)?$/
        # Add bindings

        case current
        when :symbols
          #Add a symbol to the current SymbolSet's binding

          @bindings[current_binding].add_pair($1, $2.to_i)
        when :replacements
          @replacements[$1] = $2
        else
          raise LangSyntaxError, "Runtime error when evaluating " +
                                 "\"#{@lang_file}\" at binding line #{lines_count}."
        end
      else
        if current == :expression
          # Copying expression

          @full_expression += line.strip
        else
          raise LangSyntaxError, "Runtime error when evaluating " +
                                 "\"#{@lang_file}\" at line #{lines_count}."
        end
      end

      #Counting lines

      lines_count += 1
    end
  end
end