Add pattern-matching for Emacs Muse underlines

References: #7

Author: Alhadis

grammars/muse.cson

@@ -254,6 +254,7 @@ repository:
 			{include: "#link"}
 			{include: "#footnoteReference"}
 			{include: "#nbsp"}
+			{include: "#underline"}
 		]
 
 
@@ -794,6 +795,16 @@ repository:
 			2: name: "keyword.operator.key-value.separator.muse"
 
 
+	# Underlined text (not supported in AmuseWiki)
+	underline:
+		name:  "constant.other.reference.link.muse"
+		begin: "(?<=\\W|^)_(?=[^\\s_])"
+		end:   "(?<=[^\\s_])_(?=\\W|$)|(?=^[ \\t]*$)"
+		beginCaptures: 0: name: "punctuation.definition.emphasis.begin.muse"
+		endCaptures:   0: name: "punctuation.definition.emphasis.end.muse"
+		patterns: [include: "#inline"]
+		
+
 	# Poetic stanza
 	verse:
 		name:  "markup.quote.verse.muse"

spec/fixtures/input/inline-underline.muse

@@ -0,0 +1,47 @@
+Foo _underline_ baz
+
+Foo _under line_ baz
+
+Foo _underline _ baz
+
+Foo _ underline_ baz
+
+Foo _ under line _ baz
+
+Foo _ under _ line _ baz
+
+Foo _under_line_ baz
+
+Foo __underline__ baz
+
+Foo __under line__ baz
+
+Foo __under__line__ baz
+
+Foo _under_line under_line_ baz
+
+Foo _underline *italic* underline_ baz
+
+Foo _underline **bold** underline_ baz
+
+Foo _underline ***bold italic*** underline_ baz
+
+Foo _underline
+underline_ bar
+
+_underline
+underline_ bar
+
+Foo _under line
+under line_ bar
+
+_underline
+underline_ bar
+
+Foo_ underline_ baz
+
+Foo _underline_unclosed italic
+
+Foo _underline_underline_ baz
+
+_underline

spec/muse-spec.js

@@ -81,8 +81,17 @@ describe("Muse grammar", () => {
 		});
 
 		for(const filename of files){
-			const inputFile  = fs.readFileSync(join(inputDir, filename), "utf8");
-			const outputFile = fs.readFileSync(join(outputDir, filename + ".json"), "utf8");
+			const inputPath  = join(inputDir, filename);
+			const outputPath = join(outputDir, filename + ".json");
+			
+			// Ignore pending fixtures
+			if(!fs.existsSync(outputPath)){
+				it.skip(`tokenises ${filename}`);
+				continue;
+			}
+			
+			const inputFile  = fs.readFileSync(inputPath, "utf8");
+			const outputFile = fs.readFileSync(outputPath, "utf8");
 
 			it(`tokenises ${filename}`, () => {
 				const input  = muse.tokenizeLines(inputFile);