rules.n3

@base <https://periodo.github.io/edtf-ontology/> .
@prefix edtfo: <edtfo.ttl#> .
@prefix iso8601: <http://www.opengis.net/def/uom/ISO-8601/0/> .
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix re: <rules/regexes/> .
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
@prefix time: <http://www.w3.org/2006/time#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

# non-standard eye extension
@prefix e: <http://eulersharp.sourceforge.net/2003/03swap/log-rules#> .

# These rules may result in xsd:gYear values that are larger than the
# maximum possible integer value for a platform. Such values are
# within the lexical space defined by W3C XML Schema Definition
# Language (XSD) 1.1 Part 2: Datatypes, but nevertheless they may not
# validate if they exceed the maximum possible integer value.

# exponential year

{
    re:YEAR_SIGNIFICAND = ?ys . re:YEAR_EXPONENT = ?ye

    . ?w edtfo:inEDTFDateTime ?e
    . ("^Y" ?ys "E" ?ye "$") string:concatenation ?re
    . ?e string:matches ?re
} => {
    ?w time:inDateTime [
      a time:DateTimeDescription ;
      time:unitType time:unitYear ;
    ]
} .

{
    re:YEAR_SIGNIFICAND = ?ys . re:YEAR_EXPONENT = ?ye

    . ?w edtfo:inEDTFDateTime ?e
    . ?w time:inDateTime ?dtd
    . ("^Y(" ?ys ")E" ?ye) string:concatenation ?ys_scraper
    . (?e ?ys_scraper) string:scrape ?significand
    . ("^Y" ?ys "E(" ?ye ")") string:concatenation ?ye_scraper
    . (?e ?ye_scraper) string:scrape ?exponent
    . (10 ?exponent) math:exponentiation ?power
    . (?significand ?power) math:product ?year_v
    . ("~|~`0t~d~4+" ?year_v) e:format ?year_string
    . (?year_string xsd:gYear) log:dtlit ?gyear
} => {
    ?dtd time:year ?gyear
} .

# year with significant digits

{
    re:YEAR = ?y . re:SIGNIFICANT_DIGITS = ?s

    . ?w edtfo:inEDTFDateTime ?e
    . ("^" ?y "S" ?s "$") string:concatenation ?re
    . ?e string:matches ?re

    . ("^(" ?y ")S" ?s "$") string:concatenation ?y_scraper
    . (?e ?y_scraper) string:scrape ?year
    . (?year xsd:gYear) log:dtlit ?gyear
} => {
    ?w time:inDateTime [
      a time:DateTimeDescription ;
      time:year ?gyear
    ]
} .

# letter-prefixed year with significant digits

{
    re:LETTER_PREFIXED_YEAR = ?y . re:SIGNIFICANT_DIGITS = ?s

    . ?w edtfo:inEDTFDateTime ?e
    . ("^Y" ?y "S" ?s "$") string:concatenation ?re
    . ?e string:matches ?re

    . ("^Y(" ?y ")S" ?s "$") string:concatenation ?y_scraper
    . (?e ?y_scraper) string:scrape ?year
    . (?year xsd:gYear) log:dtlit ?gyear
} => {
    ?w time:inDateTime [
      a time:DateTimeDescription ;
      time:year ?gyear
    ]
} .

# exponential year with significant digits

{
    re:YEAR_SIGNIFICAND = ?ys . re:YEAR_EXPONENT = ?ye . re:SIGNIFICANT_DIGITS = ?s

    . ?w edtfo:inEDTFDateTime ?e
    . ("^Y" ?ys "E" ?ye "S" ?s "$") string:concatenation ?re
    . ?e string:matches ?re
} => {
    ?w time:inDateTime [
      a time:DateTimeDescription ;
    ]
} .

# interpret significant digits

{
    re:SIGNIFICANT_DIGITS = ?s

    . ?w edtfo:inEDTFDateTime ?e
    . ?w time:inDateTime ?dtd
    . ?dtd time:year ?gyear
    . ?gyear e:numeral ?year
    . ("S(" ?s ")$") string:concatenation ?s_scraper
    . (?e ?s_scraper) string:scrape ?digits
    . ("max(0, (ceiling(log10(abs(_year))) - _digits))" ?year ?digits) e:calculate ?x
    . (10.0 ?x) math:exponentiation ?duration

    . ?SCOPE log:notIncludes { ?dtd time:unitType ?u }
} => {
    ?dtd time:unitType [
      a time:TemporalUnit ;
      time:years ?duration
    ]
} .

# normalize temporal units

{
    { ?x time:unitType [ a time:TemporalUnit ; time:years 1000.0 ] }
    e:becomes
    { ?x time:unitType time:unitMillenium }
} => {
    ?x time:unitType ?u
} .

{
    { ?x time:unitType [ a time:TemporalUnit ; time:years 100.0 ] }
    e:becomes
    { ?x time:unitType time:unitCentury }
} => {
    ?x time:unitType ?u
} .

{
    { ?x time:unitType [ a time:TemporalUnit ; time:years 10.0 ] }
    e:becomes
    { ?x time:unitType time:unitDecade }
} => {
    ?x time:unitType ?u
} .

{
    { ?x time:unitType [ a time:TemporalUnit ; time:years 1 ] }
    e:becomes
    { ?x time:unitType time:unitYear }
} => {
    ?x time:unitType ?u
} .