Merge branch 'github:main' into open-graph

Author: shaedrich

collections/clean-code-linters/index.md

@@ -30,6 +30,7 @@ items:
  - ansible/ansible-lint
  - dotenv-linter/dotenv-linter
  - florianschanda/miss_hit
+ - pmd/pmd
 display_name: Clean code linters
 created_by: holman
 ---

collections/opensource-testing/index.md

@@ -61,6 +61,7 @@ items:
  - trytouca/trytouca
  - HuddleEng/PhantomCSS
  - keploy/keploy
+ - vividus-framework
 display_name: OpenSource Testing Frameworks & Tools
 created_by: msupernaut
 ---

topics/iso-8601/index.md

@@ -0,0 +1,12 @@
+---
+aliases: iso8601
+related: datetime, date-format, iso-standard, edtf, date-time, timestamp, gregorian-calendar, unix-timestamp, iso8601-duration, iso8601-period
+created_by: International Organization for Standardization
+display_name: ISO 8601
+released: June 1988
+short_description: ISO 8601 is an international standard covering the worldwide exchange and communication of date and time-related data.
+topic: iso-8601
+url: https://www.iso.org/iso-8601-date-and-time-format.html
+wikipedia_url: https://en.wikipedia.org/wiki/ISO_8601
+---
+**ISO 8601** is an ISO standard that specifies representations of dates of the Gregorian calendar and times based on the 24-hour clock, as well as composite elements of them, as character strings for use in information interchange. It is also applicable for representing times and time shifts based on Coordinated Universal Time (UTC).

topics/ll-parser/index.md

@@ -0,0 +1,8 @@
+---
+display_name: LL parser
+short_description: An LL parser is a top-down parser for a restricted context-free language.
+topic: ll-parser
+related: lr-parser
+wikipedia_url: https://en.wikipedia.org/wiki/LL_parser
+---
+In computer science, an LL parser (Left-to-right, leftmost derivation) is a top-down parser for a restricted context-free language. It parses the input from Left to right, performing Leftmost derivation of the sentence. 

topics/lr-parser/index.md

@@ -0,0 +1,9 @@
+---
+display_name: LR parser
+short_description: LR parsers are a type of bottom-up parser that analyse deterministic context-free languages in linear time.
+topic: lr-parser
+aliases: lr-parsing
+related: ll-parser
+wikipedia_url: https://en.wikipedia.org/wiki/LR_parser
+---
+In computer science, LR parsers are a type of bottom-up parser that analyse deterministic context-free languages in linear time.[1] There are several variants of LR parsers: SLR parsers, LALR parsers, Canonical LR(1) parsers, Minimal LR(1) parsers, and GLR parsers. LR parsers can be generated by a parser generator from a formal grammar defining the syntax of the language to be parsed. They are widely used for the processing of computer languages.