Module: MilkTea::Lexer::Numbers

Included in:
MilkTea::Lexer
Defined in:
lib/milk_tea/core/lexer/numbers.rb

Overview

Integer and float literal lexing, including type suffixes and exponents.

Instance Method Summary collapse

Instance Method Details

#exponent_part?(line, index) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/lexer/numbers.rb', line 73

def exponent_part?(line, index)
  return false unless %w[e E].include?(line[index])

  exponent_index = index + 1
  exponent_index += 1 if %w[+ -].include?(line[exponent_index])
  digit?(line[exponent_index])
end

#lex_number(line, index, line_number, line_offset:) ⇒ Object 



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# File 'lib/milk_tea/core/lexer/numbers.rb', line 7

def lex_number(line, index, line_number, line_offset:)
  start = index
  type = :integer

  if line[index] == "0" && %w[x X b B].include?(line[index + 1])
    base_char = line[index + 1]
    index += 2
    allowed = base_char.downcase == "x" ? HEX_DIGIT_BYTE : BIN_DIGIT_BYTE
    while index < line.length && (byte = line.getbyte(index)) && allowed[byte]
      index += 1
    end
  else
    while index < line.length && (byte = line.getbyte(index)) && NUMERIC_PART_BYTE[byte]
      index += 1
    end

    if line[index] == "." && digit?(line[index + 1])
      type = :float
      index += 1
      while index < line.length && (byte = line.getbyte(index)) && NUMERIC_PART_BYTE[byte]
        index += 1
      end
    end

    if exponent_part?(line, index)
      type = :float
      index += 1
      index += 1 if %w[+ -].include?(line[index])
      while index < line.length && (byte = line.getbyte(index)) && NUMERIC_PART_BYTE[byte]
        index += 1
      end
    end
  end

  int_suffix = nil
  if type == :integer
    int_suffix = scan_integer_suffix_at(line, index)
    index += int_suffix.length if int_suffix
  end

  if type == :float && line[index] == "f" && !identifier_part?((line[index + 1] || " ").to_s)
    index += 1
  elsif type == :float && line[index] == "d" && !identifier_part?((line[index + 1] || " ").to_s)
    index += 1
  end

  lexeme = line[start...index]
  if type == :integer
    cleaned = int_suffix ? lexeme.delete_suffix(int_suffix).delete("_") : lexeme.delete("_")
    literal = parse_integer(cleaned)
  else
    normalized = lexeme.delete("_").delete_suffix("f").delete_suffix("d")
    literal = normalized.to_f
  end
  @tokens << token(type, lexeme, literal, line_number, start + 1, start_offset: line_offset + start, end_offset: line_offset + index)
  index
end

#parse_integer(lexeme) ⇒ Object 



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# File 'lib/milk_tea/core/lexer/numbers.rb', line 81

def parse_integer(lexeme)
  cleaned = lexeme.delete("_")
  case cleaned
  when /\A0[xX]/
    cleaned[2..].to_i(16)
  when /\A0[bB]/
    cleaned[2..].to_i(2)
  else
    cleaned.to_i(10)
  end
end

#scan_integer_suffix_at(line, index) ⇒ Object 



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# File 'lib/milk_tea/core/lexer/numbers.rb', line 65

def scan_integer_suffix_at(line, index)
  return nil if index >= line.length

  INTEGER_SUFFIX_STRINGS.find do |suffix|
    line[index, suffix.length] == suffix && !identifier_part?((line[index + suffix.length] || " ").to_s)
  end
end