Support Unicode middle dot (#1015)

* Support Unicode middle dot

This PR adds support for Unicode characters U+00B7 MIDDLE DOT and U+22C5 DOT OPERATOR.

* Use escapes for tests. Edit macro comment.

src/macros.js

@@ -86,6 +86,11 @@ defineMacro("\u211A", "\\mathbb{Q}");
 defineMacro("\u211D", "\\mathbb{R}");
 defineMacro("\u2124", "\\mathbb{Z}");
 
+// Unicode middle dot
+// The KaTeX fonts do not contain U+00B7. Instead, \cdotp displays
+// the dot at U+22C5 and gives it punct spacing.
+defineMacro("\u00b7", "\\cdotp");
+
 // \llap and \rlap render their contents in text mode
 defineMacro("\\llap", "\\mathllap{\\textrm{#1}}");
 defineMacro("\\rlap", "\\mathrlap{\\textrm{#1}}");

src/symbols.js

@@ -496,7 +496,7 @@ defineSymbol(math, main, mathord, "\u03c6", "\\varphi", true);
 defineSymbol(math, main, bin, "\u2217", "*");
 defineSymbol(math, main, bin, "+", "+");
 defineSymbol(math, main, bin, "\u2212", "-");
-defineSymbol(math, main, bin, "\u22c5", "\\cdot");
+defineSymbol(math, main, bin, "\u22c5", "\\cdot", true);
 defineSymbol(math, main, bin, "\u2218", "\\circ");
 defineSymbol(math, main, bin, "\u00f7", "\\div", true);
 defineSymbol(math, main, bin, "\u00b1", "\\pm", true);

test/katex-spec.js

@@ -2706,7 +2706,7 @@ describe("Unicode", function() {
     });
 
     it("should parse symbols", function() {
-        expect("£¥ðℂℍℑℓℕ℘ℙℚℜℝℤℲℵℶℷℸ⅁∀∁∂∃∇∞∠∡∢♠♡♢♣♭♮♯✓").toParse();
+        expect("£¥ðℂℍℑℓℕ℘ℙℚℜℝℤℲℵℶℷℸ⅁∀∁∂∃∇∞∠∡∢♠♡♢♣♭♮♯✓\u00b7").toParse();
     });
 
     it("should parse arrows", function() {
@@ -2718,7 +2718,7 @@ describe("Unicode", function() {
     });
 
     it("should parse binary operators", function() {
-        expect("±×÷∓∔∧∨∩∪≀⊎⊓⊔⊕⊖⊗⊘⊙⊚⊛⊝⊞⊟⊠⊡⊺⊻⊼⋇⋉⋊⋋⋌⋎⋏⋒⋓⩞").toParse();
+        expect("±×÷∓∔∧∨∩∪≀⊎⊓⊔⊕⊖⊗⊘⊙⊚⊛⊝⊞⊟⊠⊡⊺⊻⊼⋇⋉⋊⋋⋌⋎⋏⋒⋓⩞\u22C5").toParse();
     });
 });