Class: PyFormat::Field

Inherits:
Object show all
Defined in:
lib/tagen/core/string/pyformat.rb

Constant Summary collapse

PAT = 
/^ 
(?: (?<fill>[^}]+)?  (?<align>[<>=^]) )? 
(?<sign>[ +-])? 
(?<alternate>\#)? 
(?<zero_padding>0)? 
(?<width>\d+)? 
(?<comma_sep>,)? 
(?: \.(?<precision>\d+) )? 
(?<type>[bcdeEfFgGnosxX%])? /x

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Field

Returns a new instance of Field.



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# File 'lib/tagen/core/string/pyformat.rb', line 137

def initialize
	# default options
	@o = {
		fill: " ",
		align: ">",
		sign: "-",
		alternate: false,
		zero_padding: false,
		width: 0,
		comma_sep: false,
		precision: nil,
		type: nil,
	}
end

Class Method Details

.parse(spec, arg) ⇒ Object 



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# File 'lib/tagen/core/string/pyformat.rb', line 131

def self.parse spec, arg
	f = self.new 
	f.parse_spec spec if spec
	f.format arg
end

Instance Method Details

#format(arg) ⇒ String

format a <#Field> by @o

Parameters:

Returns:



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# File 'lib/tagen/core/string/pyformat.rb', line 196

def format arg
	# arg is int str ..
	# ret is str.

	case arg
	when Integer	
		@o[:type] ||= 'd'
	else  # default is s
		@o[:type] ||= 's'
	end
	
	ret = case @o[:type] 
	when 's'
		arg = arg.to_s
		@o[:precision] ? arg[0...@o[:precision]] : arg
	when 'c'
		arg.chr

	when 'b','o','d','x','X'
		arg = arg.to_i

		case @o[:type]
		when 'b'
			ret1 = arg.to_s 2
			ret1 = do_comma ret1
			@o[:alternate] ? '0b'+ret1 : ret1
		when 'o'
			ret1 = arg.to_s 8
			ret1 = do_comma ret1
			@o[:alternate] ? '0'+ret1 : ret1
		when 'd'
			ret1 = arg.to_s 10
			do_comma ret1
		when 'x', 'X'
			ret1 = arg.to_s 16
			ret1.upcase! if @o[:type]=='X'
			ret1 = do_comma ret1
			@o[:alternate] ? "0#{@o[:type]}"+ret1 : ret1
		end

	# for float, need handle 'precision'
	when 'f','F','g','G','e','E', '%'
		type = @o[:type]

		num = arg.to_f

		if type=='%'
			num = num*100 
			type = 'g'
		elsif type=='F'
			type = 'f'
		end

		# remove 0 1.00000
		if type=='f'
			sa, sb = num.to_s.split('.')
			prec = sb.length
			@o[:precision] = prec if not @o[:precision]
		elsif type=='e'
			# not implement yet
		end

		spec = "%"
		spec += '.' + @o[:precision].to_s if @o[:precision]
		spec += type

		ret1 = spec % num

		# '%g' % 1.0 => 1

		# 'comma_sep'
		if not %w(g G).include? type
			a, b = ret1.split('.') 
			a = do_comma a
			ret1 = b==nil ? a : a+'.'+b
		end

		ret1 += '%' if @o[:type]=='%'
		ret1

	end # case

	## sign
	if @o[:sign] != '-'
		sign = arg.to_f>=0 ? @o[:sign] : '-'
		ret = sign+ret
	end


	## width
	n = @o[:width] - ret.length
	if n > 0
		fill = ''
		@o[:fill].chars.cycle do |c|
			fill << c
			break if fill.length == n
		end

		ret = case @o[:align]
		when '>' then fill + ret
		when '<' then ret + fill
		when '^' then fill[0...fill.length/2] + ret + fill[fill.length/2..-1]
		when '=' then ret[0] + fill + ret[1..-1]
		end

	end
	

	ret
end

#parse_spec(spec) ⇒ nil

parse a spec string

parse_spec “this is PyFormat::Field.::.2f” return @o

Parameters:

Returns:

  • (nil)

Raises:



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# File 'lib/tagen/core/string/pyformat.rb', line 159

def parse_spec spec
	matched = PAT.match(spec)
	raise EFormatSpec, spec if not matched
	matched = matched.to_hash

	# merge @o and matched
	@o.each do |k,v|
		@o[k] = matched[k] ? matched[k] : v
	end

	# handle keys 
	@o = @o.each.with_object({}) do |(k,v),o|
		case k 
		when :width, :precision
			o[k] = v.to_i if v
		when :zero_padding
			if v
				o[:fill] = "0"
			end
		when :precision
			o[:precision] = 1 if v<1
		else
			o[k] = v
		end
	end

	if @o[:align] == "="
		@o[:fill] = "0"
		@o[:sign] = "+"
	end

end