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|
#! env ruby
# something to help examine the possible variations of a sub-pattern
# run without arguments to see usage
# mind the expontential complexity!
raw = <<-END.gsub %r{//.*$}, ''
TOP -> r(r"\A") <time_expression> r(r"\z")
// non-terminal patterns
// these are roughly ordered by dependency
time_expression => <universal> | <particular>
particular => <one_time> | <two_times>
one_time => <moment_or_period>
two_times -> ("from")? <moment_or_period> <to> <moment_or_period>
to => <up_to> | <through>
moment_or_period => <moment> | <period>
period => <named_period> | <specific_period>
specific_period => <modified_period> | <month_and_year> | <year> | <relative_period>
modified_period -> <modifier>? <modifiable_period>
// replacing [["week", "month", "year", "pay period", "payperiod", "pp", "weekend"]] with <some_period>
// because this script doesn't have handling for the [...] pattern
modifiable_period => <some_period> | <a_month> | <a_day>
month_and_year -> <a_month> <year>
year => <short_year> | ("-")? <n_year>
year -> <suffix_year> <year_suffix>
year_suffix => <ce> | <bce>
relative_period -> <count> <displacement> <from_now_or_ago>
count => r(r"[1-9][0-9]*") | <a_count>
named_period => <a_day> | <a_month>
moment -> <adjustment>? <point_in_time>
adjustment -> <amount> <direction> // two minutes before
amount -> <count> <unit>
point_in_time -> <at_time_on>? <some_day> <at_time>? | <specific_time> | <time>
at_time_on -> ("at")? <time> ("on")?
some_day => <specific_day> | <relative_day>
specific_day => <adverb> | <date_with_year>
date_with_year => <n_date> | <a_date>
n_date -> <year> r("[./-]") <n_month> r("[./-]") <n_day>
n_date -> <year> r("[./-]") <n_day> r("[./-]") <n_month>
n_date -> <n_month> r("[./-]") <n_day> r("[./-]") <year>
n_date -> <n_day> r("[./-]") <n_month> r("[./-]") <year>
a_date -> <day_prefix>? <a_month> <o_n_day> (",") <year>
a_date -> <day_prefix>? <n_day> <a_month> <year>
a_date -> <day_prefix>? ("the") <o_day> ("of") <a_month> <year>
day_prefix => <a_day> (",")?
relative_day => <a_day> | <a_day_in_month>
at_time -> ("at") <time>
specific_time => <first_time> | <last_time> | <precise_time>
precise_time -> <n_date> <hour_24>
time -> <hour_12> <am_pm>? | <hour_24> | <named_time>
hour_12 => <h12>
hour_12 => <h12> (":") <minute>
hour_12 => <h12> (":") <minute> (":") <second>
hour_24 => <h24>
hour_24 => <h24> (":") <minute>
hour_24 => <h24> (":") <minute> (":") <second>
a_day_in_month => <ordinal_day> | <day_and_month>
ordinal_day -> <day_prefix>? ("the") <o_day> // the first
o_day => <n_ordinal> | <a_ordinal> | <roman>
day_and_month -> <n_month> r("[./-]") <n_day> // 5-6
day_and_month -> <a_month> ("the")? <o_n_day> // June 5, June 5th, June fifth, June the fifth
day_and_month -> ("the") <o_day> ("of") <a_month> // the 5th of June, the fifth of June
o_n_day => <n_day> | <o_day>
END
# convert this into some partially parsed raw data for further examination
RAW = {}.tap do |h|
raw.lines.each do |l|
l.strip!
next unless l.length > 0
key, value = l.split /\s*[=-]>\s*/
list = h[key] ||= []
value.split('|').each do |piece|
list << piece.strip
end
end
end
#####
## monkey patching for convenience
#####
class String
def deep_dup
self
end
def show(depth=0)
puts " " * depth + self
end
end
class Array
def deep_dup
map{ |o| o.deep_dup }
end
def show(depth=0)
each do |o|
o.show(depth)
end
end
end
class Hash
def deep_dup
Hash[
to_a.map do |k,v|
[ k.deep_dup, v.deep_dup ]
end
]
end
def show(depth=0)
each do |k,v|
k.show(depth)
v.show(depth + 1)
end
end
end
#####
## functions for extracting variants out of the grammar
#####
def augment(list, element)
if list.length == 0
[element.deep_dup]
else
list.map do |item|
if Array === item
item.deep_dup + [element.deep_dup]
else
[ item.deep_dup, element.deep_dup ]
end
end
end
end
def variants(key)
( @variants ||= {} )[key] ||= begin
all_vs = []
( RAW[key] || [] ).each do |line|
vs = []
line .scan(/(?:<\w+>|r?\([^)]+\))\??/).each do |element|
optional = element[-1] == '?'
if optional
element = element[0..-2]
without = vs.dup
end
case element[0]
when 'r', '('
vs = augment(vs, element)
when '<'
subkey = element[1..-2]
if RAW.include? subkey
new_vs = []
variants(subkey).each do |v|
new_vs += augment(vs, { subkey => v })
end
vs = new_vs
else
vs = augment(vs, subkey)
end
end
if optional
vs = without + vs
end
end
all_vs += vs
end
all_vs
end
end
# convert a variant tree into its leaves
def leaves(obj)
case obj
when Array
obj.map{ |o| leaves o }.flatten
when Hash
obj.values.map{ |o| leaves o }.flatten
else
[obj]
end
end
#####
## the main function
#####
key = ARGV.shift
if key
variants(key).each do |v|
puts leaves(v).join(' ')
puts "-----"
v.show
puts
end
else
puts "USAGE: provide one of the following keys to see all the variants in the grammar for that key\n\n"
RAW.keys.sort.each{ |k| puts k }
end
|
