Extract date from texts in corpus R - r

Question

I have a corpus object from which I want to extract data so I can add them as docvar.
The object looks like this
v1 <- c("(SE22-y -7 A go q ,, Document of The World Bank FOR OFFICIAL USE ONLY il I ( >I8.( )]i 1 t'f-l±E C 4'( | Report No. 9529-LSO l il .rt N ,- / . t ,!I . 1. 'i 1( T v f) (: AR.) STAFF APPRAISAL REPORT KINGDOM OF LESOTHO EDUCATION SECTOR DEVELOPMENT PROJECT JUNE 19, 1991 Population and Human Resources Division Southern Africa Department This document has a restricted distribution and may be used by reipients only in the performance of their official duties. Its contents may not otherwise be disclosed without World Bank authorization.",
"Document of The World Bank Report No. 13611-PAK STAFF APPRAISAL REPORT PAKISTAN POPULATION WELFARE PROGRAM PROJECT FREBRUARY 10, 1995 Population and Human Resources Division Country Department I South Asia Region",
"I Toward an Environmental Strategy for Asia A Summary of a World Bank Discussion Paper Carter Brandon Ramesh Ramankutty The World Bank Washliington, D.C. (C 1993 The International Bank for Reconstruction and Development / THiE WORLD BANK 1818 H Street, N.W. Washington, D.C. 20433 All rights reserved Manufactured in the United States of America First printing November 1993",
"Report No. PID9188 Project Name East Timor-TP-Emergency School (#) Readiness Project Region East Asia and Pacific Region Sector Other Education Project ID TPPE70268 Borrower(s) EAST TIMOR Implementing Agency Address UNTAET (UN TRANSITIONAL ADMINISTRATION FOR EAST TIMOR) Contact Person: Cecilio Adorna, UNTAET, Dili, East Timor Fax: [phone] Environment Category C Date PID Prepared June 16, 2000 Projected Appraisal Date May 27, 2000 Projected Board Date June 20, 2000",
"Page 1 CONFORMED COPY CREDIT NUMBER 2447-CHA (Reform, Institutional Support and Preinvestment Project) between PEOPLE'S REPUBLIC OF CHINA and INTERNATIONAL DEVELOPMENT ASSOCIATION Dated December 30, 1992")
c1 <- corpus(v1)
The first thing I want to do is extract the first occurring date, mostly it occurs as "Month Year" (December 1990) or "Month Day, Year" (JUNE 19, 1991) or with a typo FREBRUARY 10, 1995 in which case the month could be discarded.
My code is a combination of
Extract date text from string
&
Extract Dates in any format from Text in R:
lapply(c1$documents$texts, function(x) anydate(str_extract_all(c1$documents$texts, "[[:alnum:]]+[ /]*\\d{2}[ /]*\\d{4}")))
and get the error:
Error in anytime_cpp(x = x, tz = tz, asUTC = asUTC, asDate = TRUE, useR = useR, : Unsupported Type
However, I do not know how to supply the date format. Furthermore, I don't really get how to write the correct regular expressions.
https://www.regular-expressions.info/dates.html & https://www.regular-expressions.info/rlanguage.html
other questions on this subject are:
Extract date from text
Need to extract date from a text file of strings in R
http://r.789695.n4.nabble.com/Regexp-extract-first-occurrence-of-date-in-string-td997254.html
Extract date from given string in r

Answer 1

str_extract_all(texts(c1)
, "(\\b(?:Jan(?:uary)?|Feb(?:ruary)?|Mar(?:ch)?|Apr(?:il)?|May|Jun(?:e)?|Jul(?:y)?|Aug(?:ust)?|Sep(?:tember)?|Nov(?:ember)?|Oct(?:ober)?|Dec(?:ember)?) (?:19[7-9]\\d|2\\d{3})(?=\\D|$))|(\\b(?:JAN(?:UARY)?|FEB(?:RUARY)?|MAR(?:CH)?|APR(?:IL)?|MAY|JUN(?:E)?|JUL(?:Y)?|AUG(?:UST)?|SEP(?:TEMBER)?|NOV(?:EMBER)?|OCT(?:OBER)?|DEC(?:EMBER)?) (?:19[7-9]\\d|2\\d{3})(?=\\D|$))|((Jan(uary)?|Feb(ruary)?|Mar(ch)?|Apr(il)?|May|Jun(e)?|Jul(y)?|Aug(ust)?|Sep(tember)?|Oct(ober)?|Nov(ember)?|Dec(ember)?)\\s+\\d{1,2},\\s+\\d{4})|(\\b(JAN(UARY)?|FEB(RUARY)?|MAR(CH)?|APR(IL)?|MAY|JUN(E)?|JUL(Y)?|AUG(UST)?|SEP(TEMBER)?|OCT(OBER)?|NOV(EMBER)?|DEC(EMBER)?)\\s+\\d{1,2},\\s+\\d{4})"
, simplify = TRUE)[,1]
This gives the first occurrence of format JUNE 19, 1991 or December 1990