feat(yasqe): support SPARQL 1.2 syntax

.changeset/sparql-1-2-syntax.md

@@ -0,0 +1,16 @@
+---
+"@matdata/yasqe": minor
+---
+
+Support SPARQL 1.2 syntax in the query editor, following the grammar of the [SPARQL 1.2 Query Language](https://www.w3.org/TR/sparql12-query/#sparqlGrammar) Working Draft of 21 September 2026. SPARQL 1.2 queries are now highlighted and syntax checked, including:
+
+- the `VERSION` declaration
+- triple terms `<<( :s :p :o )>>` in triple patterns, `VALUES` and expressions
+- reified triples `<< :s :p :o ~ :reifier >>`, reifiers (`~`) and annotation blocks `{| ... |}`. Reifiers and annotations after a property path that is not a simple predicate are reported as errors.
+- language tags with a base direction, such as `"hello"@en--ltr`
+- the new functions `LANGDIR`, `STRLANGDIR`, `hasLANG`, `hasLANGDIR`, `isTRIPLE`, `TRIPLE`, `SUBJECT`, `PREDICATE` and `OBJECT`
+- `!` applied to any unary expression, and aggregates wherever a built-in call is allowed
+
+A blank node property list followed by a property path (`[ :p ?o ] :a/:b ?c`) is no longer reported as a syntax error.
+
+Known incompatibility: a `<` comparison written without a space before a full IRI, such as `FILTER(?o<<http://example.org/a>)`, is now reported as a syntax error. SPARQL 1.2 reads `<<` as a single token (the longest match wins), so a SPARQL 1.2 parser rejects this query as well. Add a space to fix it: `FILTER(?o < <http://example.org/a>)`.

packages/yasqe/grammar/README.md

@@ -1,12 +1,16 @@
 # Yet Another SPARQL Query Editor (YASQE) grammar
 
+The grammar covers SPARQL 1.1 and SPARQL 1.2 (queries and updates).
+
 ## Prerequisites
 
-- SWI Prolog
+- SWI Prolog (`swipl` on the `PATH`)
 
 ## How to make modifications to grammar:
 
 - Change the Extended Backus-Naur Form (EBNF) grammar in file
-  `sparql11-grammar.pl`.  Do not change file `_tokenizer-table.js`.
-- Run `./build.sh`.
+  `sparql-grammar.pl`.  Do not change file `_tokenizer-table.js`.
+- Run `./build.sh`. It regenerates `_tokenizer-table.js` and formats it with prettier.
+  Check its output for `LL(1) clash` messages: the grammar must stay LL(1).
 - Finally, rebuild YASQE from the YASQE home directory by running `npm run build` (or `npm run dev` to test it locally).
+- The grammar is tested by `test/unit/yasqe-sparql12-grammar-test.ts` (`npm run unit-test`).