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-rw-r--r--ChangeLog8
-rw-r--r--lib/date.rb18
-rw-r--r--lib/date/delta.rb400
-rw-r--r--lib/date/delta/parser.rb301
-rw-r--r--lib/date/delta/parser.ry84
5 files changed, 810 insertions, 1 deletions
diff --git a/ChangeLog b/ChangeLog
index ce1ef76..5b337aa 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Mon Aug 17 08:31:56 2009 Tadayoshi Funaba <tadf@dotrb.org>
+
+ * lib/date/delta.rb: merged from date4. [experimental]
+
+ * lib/date/delta/parser.*: ditto.
+
+ * lib/date.rb: followed the above changes.
+
Mon Aug 17 08:19:03 2009 Tadayoshi Funaba <tadf@dotrb.org>
* lib/date/format.rb (strptime): removed \v; since \s includes \v.
diff --git a/lib/date.rb b/lib/date.rb
index f3edb53..802ce8e 100644
--- a/lib/date.rb
+++ b/lib/date.rb
@@ -194,6 +194,7 @@
# puts secs_to_new_year()
require 'date/format'
+require 'date/delta'
# Class representing a date.
#
@@ -1336,6 +1337,9 @@ class Date
def + (n)
case n
when Numeric; return self.class.new!(@ajd + n, @of, @sg)
+ when Delta
+ d = n.__send__(:delta)
+ return (self >> d.imag) + d.real
end
raise TypeError, 'expected numeric'
end
@@ -1352,8 +1356,11 @@ class Date
case x
when Numeric; return self.class.new!(@ajd - x, @of, @sg)
when Date; return @ajd - x.ajd
+ when Delta
+ d = x.__send__(:delta)
+ return (self << d.imag) - d.real
end
- raise TypeError, 'expected numeric or date'
+ raise TypeError, 'expected numeric'
end
# Compare this date with another date.
@@ -1371,6 +1378,12 @@ class Date
case other
when Numeric; return @ajd <=> other
when Date; return @ajd <=> other.ajd
+ else
+ begin
+ l, r = other.coerce(self)
+ return l <=> r
+ rescue NoMethodError
+ end
end
nil
end
@@ -1385,6 +1398,9 @@ class Date
case other
when Numeric; return jd == other
when Date; return jd == other.jd
+ else
+ l, r = other.coerce(self)
+ return l === r
end
false
end
diff --git a/lib/date/delta.rb b/lib/date/delta.rb
new file mode 100644
index 0000000..89034d5
--- /dev/null
+++ b/lib/date/delta.rb
@@ -0,0 +1,400 @@
+# delta.rb: Written by Tadayoshi Funaba 2004-2009
+
+require 'date'
+require 'date/delta/parser'
+
+class Date
+
+ class Delta
+
+ include Comparable
+
+ UNIT_PREFIXES = {
+ 'yotta' => Rational(10**24),
+ 'zetta' => Rational(10**21),
+ 'exa' => Rational(10**18),
+ 'peta' => Rational(10**15),
+ 'tera' => Rational(10**12),
+ 'giga' => Rational(10**9),
+ 'mega' => Rational(10**6),
+ 'kilo' => Rational(10**3),
+ 'hecto' => Rational(10**2),
+ 'deca' => Rational(10**1),
+ 'deka' => Rational(10**1),
+ 'deci' => Rational(1, 10**1),
+ 'centi' => Rational(1, 10**2),
+ 'milli' => Rational(1, 10**3),
+ 'decimilli' => Rational(1, 10**4),
+ 'centimilli' => Rational(1, 10**5),
+ 'micro' => Rational(1, 10**6),
+ 'nano' => Rational(1, 10**9),
+ 'millimicro' => Rational(1, 10**9),
+ 'pico' => Rational(1, 10**12),
+ 'micromicro' => Rational(1, 10**12),
+ 'femto' => Rational(1, 10**15),
+ 'atto' => Rational(1, 10**18),
+ 'zepto' => Rational(1, 10**21),
+ 'yocto' => Rational(1, 10**24)
+ }
+
+ IUNITS = {
+ 'year' => Complex(0, 12),
+ 'month' => Complex(0, 1)
+ }
+
+ RUNITS = {
+ 'day' => Rational(1),
+ 'week' => Rational(7),
+ 'sennight' => Rational(7),
+ 'fortnight' => Rational(14),
+ 'hour' => Rational(1, 24),
+ 'minute' => Rational(1, 1440),
+ 'second' => Rational(1, 86400)
+ }
+
+ UNIT_PREFIXES.each do |k, v|
+ RUNITS[k + 'second'] = v * RUNITS['second']
+ end
+
+ remove_const :UNIT_PREFIXES
+
+ UNITS = {}
+
+ IUNITS.each do |k, v|
+ UNITS[k] = v
+ end
+
+ RUNITS.each do |k, v|
+ UNITS[k] = v
+ end
+
+ UNITS4KEY = {}
+
+ UNITS.each do |k, v|
+ UNITS4KEY[k] = UNITS4KEY[k + 's'] = v
+ end
+
+ UNITS4KEY['y'] = UNITS4KEY['years']
+ UNITS4KEY['yr'] = UNITS4KEY['years']
+ UNITS4KEY['yrs'] = UNITS4KEY['years']
+ UNITS4KEY['m'] = UNITS4KEY['months']
+ UNITS4KEY['mo'] = UNITS4KEY['months']
+ UNITS4KEY['mon'] = UNITS4KEY['months']
+ UNITS4KEY['mnth'] = UNITS4KEY['months']
+ UNITS4KEY['mnths'] = UNITS4KEY['months']
+ UNITS4KEY['w'] = UNITS4KEY['weeks']
+ UNITS4KEY['wk'] = UNITS4KEY['weeks']
+ UNITS4KEY['d'] = UNITS4KEY['days']
+ UNITS4KEY['dy'] = UNITS4KEY['days']
+ UNITS4KEY['dys'] = UNITS4KEY['days']
+ UNITS4KEY['h'] = UNITS4KEY['hours']
+ UNITS4KEY['hr'] = UNITS4KEY['hours']
+ UNITS4KEY['hrs'] = UNITS4KEY['hours']
+ UNITS4KEY['min'] = UNITS4KEY['minutes']
+ UNITS4KEY['mins'] = UNITS4KEY['minutes']
+ UNITS4KEY['s'] = UNITS4KEY['seconds']
+ UNITS4KEY['sec'] = UNITS4KEY['seconds']
+ UNITS4KEY['secs'] = UNITS4KEY['seconds']
+ UNITS4KEY['ms'] = UNITS4KEY['milliseconds']
+ UNITS4KEY['msec'] = UNITS4KEY['milliseconds']
+ UNITS4KEY['msecs'] = UNITS4KEY['milliseconds']
+ UNITS4KEY['milli'] = UNITS4KEY['milliseconds']
+ UNITS4KEY['us'] = UNITS4KEY['microseconds']
+ UNITS4KEY['usec'] = UNITS4KEY['microseconds']
+ UNITS4KEY['usecs'] = UNITS4KEY['microseconds']
+ UNITS4KEY['micro'] = UNITS4KEY['microseconds']
+ UNITS4KEY['ns'] = UNITS4KEY['nanoseconds']
+ UNITS4KEY['nsec'] = UNITS4KEY['nanoseconds']
+ UNITS4KEY['nsecs'] = UNITS4KEY['nanoseconds']
+ UNITS4KEY['nano'] = UNITS4KEY['nanoseconds']
+
+ def self.delta_to_dhms(delta)
+ fr = delta.imag.abs
+ y, fr = fr.divmod(12)
+ m, fr = fr.divmod(1)
+
+ if delta.imag < 0
+ y = -y
+ m = -m
+ end
+
+ fr = delta.real.abs
+ ss, fr = fr.divmod(SECONDS_IN_DAY) # 4p
+ d, ss = ss.divmod(86400)
+ h, ss = ss.divmod(3600)
+ min, s = ss.divmod(60)
+
+ if delta.real < 0
+ d = -d
+ h = -h
+ min = -min
+ s = -s
+ end
+
+ return y, m, d, h, min, s, fr
+ end
+
+ def self.dhms_to_delta(y, m, d, h, min, s, fr)
+ fr = 0 if fr == 0
+ Complex(0, y.to_i * 12 + m.to_i) +
+ Rational(d * 86400 + h * 3600 + min * 60 + (s + fr), 86400) # 4p
+ end
+
+ def initialize(delta)
+ @delta = delta
+ @__ca__ = {}
+ end
+
+ class << self; alias_method :new!, :new end
+
+ def self.new(arg=0, h=0, min=0, s=0)
+ if Hash === arg
+ d = Complex(0)
+ arg.each do |k, v|
+ k = k.to_s.downcase
+ unless UNITS4KEY[k]
+ raise ArgumentError, "unknown keyword #{k}"
+ end
+ d += v * UNITS4KEY[k]
+ end
+ else
+ d = dhms_to_delta(0, 0, arg, h, min, s, 0)
+ end
+ new!(d)
+ end
+
+ UNITS.each_key do |k|
+ module_eval <<-"end;"
+ def self.#{k}s(n=1)
+ new(:d=>n * UNITS['#{k}'])
+ end
+ end;
+ end
+
+ class << self; alias_method :mins, :minutes end
+ class << self; alias_method :secs, :seconds end
+
+ def self.parse(str)
+ d = begin (@@pa ||= Parser.new).parse(str)
+ rescue Racc::ParseError
+ raise ArgumentError, 'syntax error'
+ end
+ new!(d)
+ end
+
+ def self.diff(d1, d2) new(d1.ajd - d2.ajd) end
+
+ class << self
+
+ def once(*ids) # :nodoc: -- restricted
+ for id in ids
+ module_eval <<-"end;"
+ alias_method :__#{id.object_id}__, :#{id.to_s}
+ private :__#{id.object_id}__
+ def #{id.to_s}(*args)
+ @__ca__[#{id.object_id}] ||= __#{id.object_id}__(*args)
+ end
+ end;
+ end
+ end
+
+ private :once
+
+ end
+
+ def dhms() self.class.delta_to_dhms(@delta) end
+
+ once :dhms
+
+ def delta() @delta end
+
+ protected :delta
+
+ def years() dhms[0] end
+ def months() dhms[1] end
+ def days() dhms[2] end
+ def hours() dhms[3] end
+ def minutes() dhms[4] end
+ def seconds() dhms[5] end
+ def second_fractions() dhms[6] end
+
+ alias_method :mins, :minutes
+ alias_method :secs, :seconds
+ alias_method :sec_fractions, :second_fractions
+
+ RUNITS.each_key do |k|
+ module_eval <<-"end;"
+ def in_#{k}s(u=1)
+ if @delta.imag != 0
+ raise ArgumentError, "#{k}: #{self} has month"
+ end
+ @delta.real / (u * RUNITS['#{k}'])
+ end
+ end;
+ end
+
+ alias_method :in_mins, :in_minutes
+ alias_method :in_secs, :in_seconds
+
+ def zero?() @delta.zero? end
+ def nonzero?() unless zero? then self end end
+
+ def integer? () @delta.imag == 0 && @delta.real.integer? end
+
+ def -@ () self.class.new!(-@delta) end
+ def +@ () self.class.new!(+@delta) end
+
+ def dx_addsub(m, n)
+ case n
+ when Numeric; return self.class.new!(@delta.__send__(m, n))
+ when Delta; return self.class.new!(@delta.__send__(m, n.delta))
+ else
+ l, r = n.coerce(self)
+ return l.__send__(m, r)
+ end
+ end
+
+ private :dx_addsub
+
+ def + (n) dx_addsub(:+, n) end
+ def - (n) dx_addsub(:-, n) end
+
+ def dx_muldiv(m, n)
+ case n
+ when Numeric
+ return self.class.new!(@delta.__send__(m, n))
+ else
+ l, r = n.coerce(self)
+ return l.__send__(m, r)
+ end
+ end
+
+ private :dx_muldiv
+
+ def * (n) dx_muldiv(:*, n) end
+ def / (n) dx_muldiv(:/, n) end
+
+ def dx_conv1(m, n)
+ if @delta.imag != 0
+ raise ArgumentError, "#{m}: #{self} has month"
+ end
+ case n
+ when Numeric
+ return self.class.new!(Complex(@delta.real.__send__(m, n), 0))
+ else
+ l, r = n.coerce(self)
+ return l.__send__(m, r)
+ end
+ end
+
+ private :dx_conv1
+
+ def % (n) dx_conv1(:%, n) end
+
+ def div(n) dx_conv1(:div, n) end
+ def modulo(n) dx_conv1(:modulo, n) end
+ def divmod(n) [div(n), modulo(n)] end
+
+ def quotient(n)
+ if @delta.imag != 0
+ raise ArgumentError, "quotient: #{self} has month"
+ end
+ case n
+ when Numeric
+ return self.class.new!(Complex((@delta.real / n).truncate))
+ else
+ l, r = n.coerce(self)
+ return l.__send__(m, r)
+ end
+ end
+
+ def remainder(n) dx_conv1(:remainder, n) end
+ def quotrem(n) [quotient(n), remainder(n)] end
+
+ def ** (n) dx_conv1(:**, n) end
+ def quo(n) dx_muldiv(:quo, n) end
+
+ def <=> (other)
+ if @delta.imag != 0
+ raise ArgumentError, "<=>: #{self} has month"
+ end
+ case other
+ when Numeric; return @delta.real <=> other
+ when Delta; return @delta.real <=> other.delta.real
+ else
+ begin
+ l, r = other.coerce(self)
+ return l <=> r
+ rescue NoMethodError
+ end
+ end
+ nil
+ end
+
+ def == (other)
+ case other
+ when Numeric; return @delta == other
+ when Delta; return @delta == other
+ else
+ begin
+ l, r = other.coerce(self)
+ return l == r
+ rescue NoMethodError
+ end
+ end
+ nil
+ end
+
+ def coerce(other)
+ case other
+ when Numeric; return other, @delta
+ else
+ super
+ end
+ end
+
+ def eql? (other) Delta === other && self == other end
+ def hash() @delta.hash end
+
+ def dx_conv0(m)
+ if @delta.imag != 0
+ raise ArgumentError, "#{m}: #{self} has month"
+ end
+ @delta.real.__send__(m)
+ end
+
+ private :dx_conv0
+
+ def abs() dx_conv0(:abs) end
+
+ def ceil() dx_conv0(:ceil) end
+ def floor() dx_conv0(:floor) end
+ def round() dx_conv0(:round) end
+ def truncate() dx_conv0(:truncate) end
+
+ def to_i() dx_conv0(:to_i) end
+ def to_f() dx_conv0(:to_f) end
+ def to_r() dx_conv0(:to_r) end
+
+ alias_method :to_int, :to_i
+
+ def inspect() format('#<%s: %s (%s)>', self.class, to_s, @delta) end
+
+ def to_s
+ format(%(%s(%dd %.02d:%02d'%02d"%03d)%s(%dy %dm)), # '
+ if @delta.real < 0 then '-' else '+' end,
+ days.abs, hours.abs, mins.abs, secs.abs, sec_fractions.abs * 1000,
+ if @delta.imag < 0 then '-' else '+' end,
+ years.abs, months.abs)
+ end
+
+ def marshal_dump() @delta end
+
+ def marshal_load(a)
+ @delta = a
+ @__ca__ = {}
+ end
+
+ end
+
+end
diff --git a/lib/date/delta/parser.rb b/lib/date/delta/parser.rb
new file mode 100644
index 0000000..7efe29f
--- /dev/null
+++ b/lib/date/delta/parser.rb
@@ -0,0 +1,301 @@
+#
+# DO NOT MODIFY!!!!
+# This file is automatically generated by racc 1.4.5
+# from racc grammer file "parser.ry".
+#
+
+require 'racc/parser'
+
+
+class Date
+
+ class Delta
+
+ class Parser < Racc::Parser
+
+module_eval <<'..end parser.ry modeval..id43bff5dec9', 'parser.ry', 42
+
+ def lookup(str)
+ t = str.downcase
+ k = UNITS4KEY[t]
+ return [:UNIT, k] if k
+ return [:AND, nil] if t == 'and'
+ return [:UNKNOWNWORD, nil]
+ end
+
+ def parse(str)
+ @q = []
+ until str.empty?
+ case str
+ when /\A\s+/
+ when /\AP(\d+y)?(\d+m)?(\d+d)?t?(\d+h)?(\d+m)?(\d+s)?(\d+w)?/i
+ y, m, d, h, min, s, w =
+ [$1, $2, $3, $4, $5, $6, $7].collect{|x| x.to_i}
+ y *= UNITS4KEY['years']
+ m *= UNITS4KEY['months']
+ d *= UNITS4KEY['days']
+ h *= UNITS4KEY['hours']
+ min *= UNITS4KEY['minutes']
+ s *= UNITS4KEY['seconds']
+ w *= UNITS4KEY['weeks']
+ @q.push [:DURATION, y + m + d + h + min + s + w]
+ when /\A\d+/
+ @q.push [:DIGITS, $&.to_i]
+ when /\A[a-z]+/i
+ @q.push lookup($&)
+ when /\A.|\n/
+ @q.push [$&, $&]
+ end
+ str = $'
+ end
+ @q.push [false, false]
+ do_parse
+ end
+
+ def next_token
+ @q.shift
+ end
+
+..end parser.ry modeval..id43bff5dec9
+
+##### racc 1.4.5 generates ###
+
+racc_reduce_table = [
+ 0, 0, :racc_error,
+ 1, 16, :_reduce_none,
+ 1, 17, :_reduce_none,
+ 1, 17, :_reduce_none,
+ 3, 17, :_reduce_4,
+ 3, 17, :_reduce_5,
+ 3, 17, :_reduce_6,
+ 3, 17, :_reduce_7,
+ 3, 17, :_reduce_8,
+ 3, 17, :_reduce_9,
+ 3, 17, :_reduce_10,
+ 2, 17, :_reduce_11,
+ 2, 17, :_reduce_12,
+ 3, 17, :_reduce_13,
+ 2, 18, :_reduce_14,
+ 0, 20, :_reduce_15,
+ 1, 20, :_reduce_none,
+ 1, 19, :_reduce_none ]
+
+racc_reduce_n = 18
+
+racc_shift_n = 32
+
+racc_action_table = [
+ 13, 14, 15, 16, 17, 18, 19, 4, 27, 23,
+ 8, 9, 1, 4, 25, 2, 8, 9, 1, 4,
+ 24, 2, 8, 9, 1, 4, 21, 2, 8, 9,
+ 1, 4, 11, 2, 8, 9, 1, 4, 26, 2,
+ 8, 9, 1, 4, nil, 2, 8, 9, 1, 4,
+ nil, 2, 8, 9, 1, nil, nil, 2, 13, 14,
+ 15, 16, 17, 18, 19, 13, 14, 15, 13, 14,
+ 15, 13, 14, 15, 13, 14, 15 ]
+
+racc_action_check = [
+ 10, 10, 10, 10, 10, 10, 10, 17, 15, 10,
+ 17, 17, 17, 18, 13, 17, 18, 18, 18, 4,
+ 11, 18, 4, 4, 4, 1, 9, 4, 1, 1,
+ 1, 8, 3, 1, 8, 8, 8, 19, 14, 8,
+ 19, 19, 19, 0, nil, 19, 0, 0, 0, 16,
+ nil, 0, 16, 16, 16, nil, nil, 16, 5, 5,
+ 5, 5, 5, 5, 5, 30, 30, 30, 28, 28,
+ 28, 29, 29, 29, 31, 31, 31 ]
+
+racc_action_pointer = [
+ 37, 19, nil, 32, 13, 55, nil, nil, 25, 13,
+ -3, 20, nil, 4, 28, -2, 43, 1, 7, 31,
+ nil, nil, nil, nil, nil, nil, nil, nil, 65, 68,
+ 62, 71 ]
+
+racc_action_default = [
+ -18, -18, -17, -18, -18, -1, -2, -3, -18, -15,
+ -18, -18, -12, -18, -18, -18, -18, -18, -18, -18,
+ -11, -16, -14, -13, 32, -10, -8, -9, -4, -5,
+ -6, -7 ]
+
+racc_goto_table = [
+ 5, 10, 3, 22, 12, nil, nil, nil, 20, nil,
+ nil, nil, nil, nil, nil, nil, 28, 29, 30, 31 ]
+
+racc_goto_check = [
+ 2, 2, 1, 5, 2, nil, nil, nil, 2, nil,
+ nil, nil, nil, nil, nil, nil, 2, 2, 2, 2 ]
+
+racc_goto_pointer = [
+ nil, 2, 0, nil, nil, -6 ]
+
+racc_goto_default = [
+ nil, nil, nil, 6, 7, nil ]
+
+racc_token_table = {
+ false => 0,
+ Object.new => 1,
+ :UNARY => 2,
+ "^" => 3,
+ "*" => 4,
+ "/" => 5,
+ "+" => 6,
+ "," => 7,
+ :AND => 8,
+ "-" => 9,
+ :DIGITS => 10,
+ "(" => 11,
+ ")" => 12,
+ :UNIT => 13,
+ :DURATION => 14 }
+
+racc_use_result_var = true
+
+racc_nt_base = 15
+
+Racc_arg = [
+ racc_action_table,
+ racc_action_check,
+ racc_action_default,
+ racc_action_pointer,
+ racc_goto_table,
+ racc_goto_check,
+ racc_goto_default,
+ racc_goto_pointer,
+ racc_nt_base,
+ racc_reduce_table,
+ racc_token_table,
+ racc_shift_n,
+ racc_reduce_n,
+ racc_use_result_var ]
+
+Racc_token_to_s_table = [
+'$end',
+'error',
+'UNARY',
+'"^"',
+'"*"',
+'"/"',
+'"+"',
+'","',
+'AND',
+'"-"',
+'DIGITS',
+'"("',
+'")"',
+'UNIT',
+'DURATION',
+'$start',
+'stmt',
+'expr',
+'time',
+'iso',
+'unit']
+
+Racc_debug_parser = false
+
+##### racc system variables end #####
+
+ # reduce 0 omitted
+
+ # reduce 1 omitted
+
+ # reduce 2 omitted
+
+ # reduce 3 omitted
+
+module_eval <<'.,.,', 'parser.ry', 18
+ def _reduce_4( val, _values, result )
+result += val[2]
+ result
+ end
+.,.,
+
+module_eval <<'.,.,', 'parser.ry', 19
+ def _reduce_5( val, _values, result )
+result += val[2]
+ result
+ end
+.,.,
+
+module_eval <<'.,.,', 'parser.ry', 20
+ def _reduce_6( val, _values, result )
+result += val[2]
+ result
+ end
+.,.,
+
+module_eval <<'.,.,', 'parser.ry', 21
+ def _reduce_7( val, _values, result )
+result -= val[2]
+ result
+ end
+.,.,
+
+module_eval <<'.,.,', 'parser.ry', 22
+ def _reduce_8( val, _values, result )
+result *= val[2]
+ result
+ end
+.,.,
+
+module_eval <<'.,.,', 'parser.ry', 23
+ def _reduce_9( val, _values, result )
+result /= val[2]
+ result
+ end
+.,.,
+
+module_eval <<'.,.,', 'parser.ry', 24
+ def _reduce_10( val, _values, result )
+result **= val[2]
+ result
+ end
+.,.,
+
+module_eval <<'.,.,', 'parser.ry', 25
+ def _reduce_11( val, _values, result )
+result = -val[1]
+ result
+ end
+.,.,
+
+module_eval <<'.,.,', 'parser.ry', 26
+ def _reduce_12( val, _values, result )
+result = +val[1]
+ result
+ end
+.,.,
+
+module_eval <<'.,.,', 'parser.ry', 27
+ def _reduce_13( val, _values, result )
+result = val[1]
+ result
+ end
+.,.,
+
+module_eval <<'.,.,', 'parser.ry', 30
+ def _reduce_14( val, _values, result )
+result = val[0] * val[1]
+ result
+ end
+.,.,
+
+module_eval <<'.,.,', 'parser.ry', 33
+ def _reduce_15( val, _values, result )
+result = 1
+ result
+ end
+.,.,
+
+ # reduce 16 omitted
+
+ # reduce 17 omitted
+
+ def _reduce_none( val, _values, result )
+ result
+ end
+
+ end # class Parser
+
+ end # class Delta
+
+end # class Date
diff --git a/lib/date/delta/parser.ry b/lib/date/delta/parser.ry
new file mode 100644
index 0000000..84d4c22
--- /dev/null
+++ b/lib/date/delta/parser.ry
@@ -0,0 +1,84 @@
+# parser.ry: Written by Tadayoshi Funaba 2006,2008,2009 -*- ruby -*-
+
+class Date::Delta::Parser
+
+ prechigh
+ nonassoc UNARY
+ left '^'
+ left '*' '/'
+ left '+' ',' AND '-'
+ preclow
+
+ rule
+
+ stmt : expr
+ ;
+
+ expr : time
+ | iso
+ | expr '+' expr {result += val[2]}
+ | expr ',' expr {result += val[2]}
+ | expr AND expr {result += val[2]}
+ | expr '-' expr {result -= val[2]}
+ | expr '*' DIGITS {result *= val[2]}
+ | expr '/' DIGITS {result /= val[2]}
+ | expr '^' DIGITS {result **= val[2]}
+ | '-' expr =UNARY {result = -val[1]}
+ | '+' expr =UNARY {result = +val[1]}
+ | '(' expr ')' {result = val[1]}
+ ;
+
+ time : DIGITS unit {result = val[0] * val[1]}
+ ;
+
+ unit : {result = 1} | UNIT
+ ;
+
+ iso : DURATION
+ ;
+
+---- header ----
+---- inner ----
+
+ def lookup(str)
+ t = str.downcase
+ k = UNITS4KEY[t]
+ return [:UNIT, k] if k
+ return [:AND, nil] if t == 'and'
+ return [:UNKNOWNWORD, nil]
+ end
+
+ def parse(str)
+ @q = []
+ until str.empty?
+ case str
+ when /\A\s+/
+ when /\AP(\d+y)?(\d+m)?(\d+d)?t?(\d+h)?(\d+m)?(\d+s)?(\d+w)?/i
+ y, m, d, h, min, s, w =
+ [$1, $2, $3, $4, $5, $6, $7].collect{|x| x.to_i}
+ y *= UNITS4KEY['years']
+ m *= UNITS4KEY['months']
+ d *= UNITS4KEY['days']
+ h *= UNITS4KEY['hours']
+ min *= UNITS4KEY['minutes']
+ s *= UNITS4KEY['seconds']
+ w *= UNITS4KEY['weeks']
+ @q.push [:DURATION, y + m + d + h + min + s + w]
+ when /\A\d+/
+ @q.push [:DIGITS, $&.to_i]
+ when /\A[a-z]+/i
+ @q.push lookup($&)
+ when /\A.|\n/
+ @q.push [$&, $&]
+ end
+ str = $'
+ end
+ @q.push [false, false]
+ do_parse
+ end
+
+ def next_token
+ @q.shift
+ end
+
+---- footer ----