flycheck validation (Turtle)

[VladimirAlexiev]

Turtle mode setup:

(autoload 'n3-mode "n3-mode")
(define-derived-mode Turtle-mode n3-mode "Turtle")
(add-hook 'Turtle-mode-hook 'turn-on-font-lock)

(add-to-list 'auto-mode-alist '("\\.ttl$"    . Turtle-mode))
(add-to-list 'auto-mode-alist '("\\.ttls$"   . Turtle-mode)) ; TODO: Extend for Turtle*. http://graphdb.ontotext.com/documentation/9.2/free/devhub/rdf-sparql-star.html#mime-types-and-file-extensions-for-rdf-in-rdf4j
(add-to-list 'auto-mode-alist '("\\.trig$"   . Turtle-mode))
(add-to-list 'auto-mode-alist '("\\.r2rml$"  . Turtle-mode))
(add-to-list 'auto-mode-alist '("\\.shacl$"  . Turtle-mode))
(add-to-list 'auto-mode-alist '("\\.n3$"     . Turtle-mode))
(add-to-list 'auto-mode-alist '("\\.nt$"     . Turtle-mode))
(add-to-list 'auto-mode-alist '("\\.owl$"    . Turtle-mode))

Turtle validation with jena riot.

(flycheck-define-checker rdf-riot
  "RDF syntax checker using riot and script riotval.pl to prepend prefixes.ttl."
  :command ("perl" "-S" "riotval.pl" source)
  :error-patterns
  ((error "ERROR riot " (* " ") ":: [line: " line ", col: " column (* " ") "] " (message)))
  :modes (n3-mode ttl-mode Turtle-mode))
(add-to-list 'flycheck-checkers 'rdf-riot)

This uses an extra script riotval.pl to prepend prefixes.ttl (as used by rdfpuml), then subtract its length from error messages:

#!perl -w
# Validate a turtle file with riot --validate; optionally prepending prefixes.ttl

my $file = shift or die "usage: riotval file.(ttl|trig)\n";
my $syntax = $file =~ m{\\.ttl$} ? "turtle" : "trig";
if (-e "prefixes.ttl") {
  my ($lines) = `wc -l prefixes.ttl` =~ m{(\d+)};
  my $out = `cat prefixes.ttl $file | riot --validate --syntax $syntax - 2>&1`;
  $out =~ s{(?<=:: \[line: )(\d+)}{$1 - $lines}ge;
  print $out
} else {
  print `riot --validate --syntax $syntax $file`
}

If you don't use prefixes.ttl then things get simpler:

  :command ("riot" "--validate" source)