Class: Symbol

Inherits:

Object

• Object
• Symbol

Defined in:

lib/HDLRuby/hruby_high.rb,
lib/HDLRuby/hruby_low2sym.rb

Overview

Extends the Symbol class with of equivalent HDLRuby object.

Constant Summary

High =

HDLRuby::High

Instance Method Summary

• #to_hdr ⇒ Object

  Convert to the equivalent HDLRuby object if any, returns nil if not.

• #to_value ⇒ Object (also: #to_expr)

  Converts to a new value.

• #to_value? ⇒ Boolean

  Tell if the expression can be converted to a value.

Instance Method Details

#to_hdr ⇒ Object

Convert to the equivalent HDLRuby object if any, returns nil if not.

# File 'lib/HDLRuby/hruby_low2sym.rb', line 49

def to_hdr
    return Low2Symbol::Symbol2LowTable[self]
end

#to_value ⇒ Object Also known as: to_expr

Converts to a new value.

Returns nil if no value can be obtained from it.

# File 'lib/HDLRuby/hruby_high.rb', line 4163

def to_value
    str = self.to_s
    return nil if str[0] != "_" # Bit string are prefixed by "_"
    # Remove the "_" not needed any longer.
    str = str[1..-1]
    # Get and check the type
    type = str[0]
    if type == "0" or type == "1" or type == "z" or type == "Z" then
        # Default binary
        type = "b"
    else
        # Not a default type
        str = str[1..-1]
    end
    return nil if str.empty?
    return nil unless ["b","u","s"].include?(type)
    # Get the width if any.
    if str[0].match(/[0-9]/) then
        width = str.scan(/[0-9]*/)[0]
    else
        width = nil
    end
    # puts "width=#{width}"
    old_str = str # Save the string it this state since its first chars
                  # can be erroneously considered as giving the width
    str = str[width.size..-1] if width
    # Get the base and the value
    base = str[0]
    # puts "base=#{base}\n"
    unless ["b", "o", "d", "h"].include?(base) then
        # No base found, default is bit
        base = "b"
        # And the width was actually a part of the value.
        value = old_str
        width = nil
    else
        # Get the value.
        value = str[1..-1]
    end
    # puts "value=#{value}"
    # Compute the bit width and the value
    case base
    when "b" then
        # base 2, compute the width
        width = width ? width.to_i : value.size
        # Check the value
        return nil unless value.match(/^[0-1zxZX]+$/)
    when "o" then
        # base 8, compute the width
        width = width ? width.to_i : value.size * 3
        # Check the value
        if value.match(/^[0-7xXzZ]+$/) then
            # 4-state value, conpute the correspondig bit string.
            value = value.each_char.map do |c|
                c = c.upcase
                if c == "X" or c.upcase == "Z" then
                    c * 3
                else
                    c.to_i(8).to_s(2).rjust(3,"0")
                end
            end.join
        else
            # Invalid value
            return nil
        end
    when "d" then
        # base 10, compute the width 
        width = width ? width.to_i : value.to_i.to_s(2).size + 1
        # Check the value
        return nil unless value.match(/^[0-9]+$/)
        # Compute it (base 10 values cannot be 4-state!)
        value = value.to_i.to_s(2)
    when "h" then
        # base 16, compute the width
        width = width ? width.to_i : value.size * 4
        # Check the value
        if value.match(/^[0-9a-fA-FxXzZ]+$/) then
            # 4-state value, conpute the correspondig bit string.
            value = value.each_char.map do |c|
                c = c.upcase
                if c == "X" or c.upcase == "Z" then
                    c * 4
                else
                    c.to_i(16).to_s(2).rjust(4,"0")
                end
            end.join
        else
            # Invalid value
            return nil
        end
    else
        # Unknown base
        return nil
    end
    # Compute the type.
    case type
    when "b" then
        type = bit[width]
    when "u" then
        type = unsigned[width]
    when "s" then
        type = signed[width]
    else
        # Unknown type
        return nil
    end
    # puts "type.width=#{type.width}, value=#{value}"
    # Create and return the value.
    return Value.new(type,value)
end

#to_value? ⇒ Boolean

Tell if the expression can be converted to a value.

Returns:

• (Boolean)

# File 'lib/HDLRuby/hruby_high.rb', line 4156

def to_value?
    return true
end