Fix a typo into the lables regex for PromQL lexer

pabluk · alecthomas · commit 9866a7516115 · 2021-04-25T08:01:36.000+10:00
The correct label matching operator is `!~` instead of `~!`.
diff --git a/lexers/p/promql.go b/lexers/p/promql.go
@@ -44,7 +44,7 @@ func promqlRules() Rules {
 			{`\n`, TextWhitespace, nil},
 			{`\s+`, TextWhitespace, nil},
 			{`,`, Punctuation, nil},
-			{`([_a-zA-Z][a-zA-Z0-9_]*?)(\s*?)(=~|!=|=|~!)(\s*?)("|')(.*?)("|')`, ByGroups(NameLabel, TextWhitespace, Operator, TextWhitespace, Punctuation, LiteralString, Punctuation), nil},
+			{`([_a-zA-Z][a-zA-Z0-9_]*?)(\s*?)(=~|!=|=|!~)(\s*?)("|')(.*?)("|')`, ByGroups(NameLabel, TextWhitespace, Operator, TextWhitespace, Punctuation, LiteralString, Punctuation), nil},
 		},
 		"range": {
 			{`\]`, Punctuation, Pop(1)},
diff --git a/lexers/testdata/promql.actual b/lexers/testdata/promql.actual
@@ -31,3 +31,6 @@ label_replace(
 
 # Values for labels enclosed within single quotes
 metric_test_app{app='turtle',proc='web'}
+
+# Use label matching operator `!~`
+metric_test_app{status!~'(4|5)..'}
diff --git a/lexers/testdata/promql.expected b/lexers/testdata/promql.expected
@@ -180,5 +180,15 @@
   {"type":"Punctuation","value":"'"},
   {"type":"LiteralString","value":"web"},
   {"type":"Punctuation","value":"'}"},
+  {"type":"TextWhitespace","value":"\n\n"},
+  {"type":"CommentSingle","value":"# Use label matching operator `!~`"},
+  {"type":"TextWhitespace","value":"\n"},
+  {"type":"NameVariable","value":"metric_test_app"},
+  {"type":"Punctuation","value":"{"},
+  {"type":"NameLabel","value":"status"},
+  {"type":"Operator","value":"!~"},
+  {"type":"Punctuation","value":"'"},
+  {"type":"LiteralString","value":"(4|5).."},
+  {"type":"Punctuation","value":"'}"},
   {"type":"TextWhitespace","value":"\n"}
 ]
