Class: Rigrate::Parser

Inherits:
Object
  • Object
show all
Includes:
Migration
Defined in:
lib/rigrate/parser.rb

Defined Under Namespace

Modules: LexStatus, StringType, TokenType Classes: Token

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Migration

#data_source, #join, #migrate, #minus, #self_eval, #union

Instance Attribute Details

#tokens ⇒ Object

Returns the value of attribute tokens.



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# File 'lib/rigrate/parser.rb', line 32

def tokens
  @tokens
end

Instance Method Details

#full_parse(tks) ⇒ Object

private



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# File 'lib/rigrate/parser.rb', line 127

def full_parse(tks)
  while tks.size > 0
    parse_rs_or_migrate_exp(tks)
  end
end

#get_token_type(str) ⇒ Object 



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# File 'lib/rigrate/parser.rb', line 266

def get_token_type(str)
  TokenType.const_get(str.strip.upcase) 
end

#is_a_token?(str) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rigrate/parser.rb', line 262

def is_a_token?(str)
  TokenType.constants.include? str.strip.upcase.to_sym
end

#lex(str) ⇒ Object

load script str -> tokens

TODO there is a bug need to fixed, when comment str include FROM key word will praser error.



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# File 'lib/rigrate/parser.rb', line 37

def lex(str)
  status = LexStatus::INIT
  @tokens = []
  t_token = ''
  t_sub_token = ''
  string_type = StringType::DOUBLE_QUOTE
  char_arr = str.chars
  loop do
    c = char_arr.shift

    if c == nil
      token = Token.new TokenType::RUBY_STR, t_token
      @tokens << token
      break
    end

    if status == LexStatus::IN_KEYWORD && c =~ /\s/
      if is_a_token?(t_token)
        @tokens << (Token.new get_token_type(t_token), t_token)
        t_token = ''
        t_sub_token = ''
        status = LexStatus::INIT
        next
      else
        status = LexStatus::IN_RUBY_CODE
      end
    end

    if status != LexStatus::IN_RUBY_CODE && status != LexStatus::IN_RUBY_STR
      (status = LexStatus::INIT && next) if c =~ /\s/
    end

    t_token << c
    t_sub_token << c

    if status == LexStatus::IN_RUBY_CODE ||
      status == LexStatus::IN_KEYWORD
      if c == '"'
        string_type = StringType::DOUBLE_QUOTE
        status = LexStatus::IN_RUBY_STR
        next
      elsif c == "'"
        string_type = StringType::SINGLE_QUOTE
        status = LexStatus::IN_RUBY_STR
        next
      end
    end

    if status == LexStatus::IN_RUBY_STR
      is_matched = false
      if (string_type == StringType::DOUBLE_QUOTE && c == '"') ||
         (string_type == StringType::SINGLE_QUOTE && c == "'")
        is_matched = true
      end
      
      if is_matched && t_token[-1] != "\\"
        status = LexStatus::IN_RUBY_CODE
      elsif c =~ /\s/
        t_sub_token = ''
      end
    end

    if status == LexStatus::IN_RUBY_CODE && c =~ /\s/
      if is_a_token? t_sub_token
        token = Token.new TokenType::RUBY_STR, t_token.sub(/#{t_sub_token}$/, '')
        @tokens << token
        token = Token.new get_token_type(t_sub_token), t_sub_token
        @tokens << token

        status = LexStatus::INIT
        t_token = ''
      end

      t_sub_token = ''
    end

    if status == LexStatus::INIT
      status = LexStatus::IN_KEYWORD
    end
  end

  self
end

#parse_condition_exp(tks) ⇒ Object 



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# File 'lib/rigrate/parser.rb', line 214

def parse_condition_exp(tks)
  token = tks.shift
  return if token.nil?

  if token.type == TokenType::ON
    v1 = parse_rs_exp(tks)

    if v1.nil?
      raise ParserError.new("ON expression should end with a [RUBY_STR]")
    end
  else
    tks.unshift token
    return
  end

  v1
end

#parse_migrate_exp(tks) ⇒ Object 



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# File 'lib/rigrate/parser.rb', line 146

def parse_migrate_exp(tks)
  token = tks.shift

  if token.type == TokenType::FROM
    v1 = parse_operate_exp(tks)

    sub_token = tks.shift
    if sub_token.type == TokenType::TO
      v2 = parse_rs_exp(tks)
      v3 = parse_condition_exp(tks)
      v4 = parse_using_exp(tks)
      migrate(v1, v2, v3, v4)

      # sub_token_1 = tks.shift
      # if not sub_token_1.nil?
      #   if sub_token_1.type == TokenType::ON
      #     cond = tks.shift
      #     migrate(v1, v2, cond)
      #   else
      #     tks.unshift sub_token_1
      #     migrate(v1, v2)
      #   end
      # else
      #   migrate(v1, v2)
      # end
    else
      raise ParserError.new("Syntax Error: need TO expression")
    end
  end
end

#parse_operate_exp(tks) ⇒ Object 



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# File 'lib/rigrate/parser.rb', line 177

def parse_operate_exp(tks)
  v1 = parse_rs_exp(tks)

  while true
    token = tks.shift
    if token.type != TokenType::UNION &&
       token.type != TokenType::JOIN &&
       token.type != TokenType::MINUS
      tks.unshift token
      break
    end

    v2 = parse_rs_exp(tks)
    if token.type == TokenType::UNION
      v1 = union(v1, v2)
    elsif token.type == TokenType::MINUS
      v1 = minus(v1, v2) 
    elsif token.type == TokenType::JOIN
      sub_token = tks.shift

      if not sub_token.nil?
        if sub_token.type == TokenType::ON
          cond = tks.shift
          v1 = join(v1, v2, cond.value)
        else
          tks.unshift sub_token
          v1 = join(v1, v2)
        end
      else
        v1 = join(v1, v2)
      end
    end
  end

  v1
end

#parse_rs_exp(tks) ⇒ Object

TODO return value should change



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# File 'lib/rigrate/parser.rb', line 251

def parse_rs_exp(tks)
  token = tks.shift
  return if token.nil?

  if token.type == TokenType::RUBY_STR
    return token.value
  else
    raise ParserError.new("Invalid Syntax")
  end
end

#parse_rs_or_migrate_exp(tks) ⇒ Object 



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# File 'lib/rigrate/parser.rb', line 133

def parse_rs_or_migrate_exp(tks)
  token = tks.shift

  if token.type == TokenType::RUBY_STR
    v1 = self_eval token.value
  else
    tks.unshift token
    v1 = parse_migrate_exp(tks)
  end

  v1
end

#parse_using_exp(tks) ⇒ Object 



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# File 'lib/rigrate/parser.rb', line 232

def parse_using_exp(tks)
  token = tks.shift
  return if token.nil?

  if token.type == TokenType::USING
    v1 = parse_rs_exp(tks)

    if v1.nil?
      raise ParserError.new("USING expression should end with a [RUBY_STR]")
    end
  else
    tks.unshift token
    return
  end

  v1
end

#parsing ⇒ Object 



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# File 'lib/rigrate/parser.rb', line 121

def parsing
  full_parse tokens.dup
end