Support stretchy wide elements. (#670)

test/katex-spec.js

@@ -1797,8 +1797,12 @@ describe("An accent parser", function() {
         expect(parse.type).toEqual("supsub");
     });
 
-    it("should not parse expanding accents", function() {
-        expect("\\widehat{x}").toNotParse();
+    it("should parse stretchy, shifty accents", function() {
+        expect("\\widehat{x}").toParse();
+    });
+
+    it("should parse stretchy, non-shifty accents", function() {
+        expect("\\overrightarrow{x}").toParse();
     });
 });
 
@@ -1819,6 +1823,234 @@ describe("An accent builder", function() {
     });
 });
 
+describe("A stretchy and shifty accent builder", function() {
+    it("should not fail", function() {
+        expect("\\widehat{AB}").toBuild();
+        expect("\\widehat{AB}^2").toBuild();
+        expect("\\widehat{AB}_2").toBuild();
+        expect("\\widehat{AB}_2^2").toBuild();
+    });
+
+    it("should produce mords", function() {
+        expect(getBuilt("\\widehat{AB}")[0].classes).toContain("mord");
+        expect(getBuilt("\\widehat +")[0].classes).toContain("mord");
+        expect(getBuilt("\\widehat +")[0].classes).not.toContain("mbin");
+        expect(getBuilt("\\widehat )^2")[0].classes).toContain("mord");
+        expect(getBuilt("\\widehat )^2")[0].classes).not.toContain("mclose");
+    });
+});
+
+describe("A stretchy and non-shifty accent builder", function() {
+    it("should not fail", function() {
+        expect("\\overrightarrow{AB}").toBuild();
+        expect("\\overrightarrow{AB}^2").toBuild();
+        expect("\\overrightarrow{AB}_2").toBuild();
+        expect("\\overrightarrow{AB}_2^2").toBuild();
+    });
+
+    it("should produce mords", function() {
+        expect(getBuilt("\\overrightarrow{AB}")[0].classes).toContain("mord");
+        expect(getBuilt("\\overrightarrow +")[0].classes).toContain("mord");
+        expect(getBuilt("\\overrightarrow +")[0].classes).not.toContain("mbin");
+        expect(getBuilt("\\overrightarrow )^2")[0].classes).toContain("mord");
+        expect(getBuilt("\\overrightarrow )^2")[0].classes).not.toContain("mclose");
+    });
+});
+
+describe("An under-accent parser", function() {
+    it("should not fail", function() {
+        expect("\\underrightarrow{x}").toParse();
+        expect("\\underrightarrow{x^2}").toParse();
+        expect("\\underrightarrow{x}^2").toParse();
+        expect("\\underrightarrow x").toParse();
+    });
+
+    it("should produce accentUnder", function() {
+        const parse = getParsed("\\underrightarrow x")[0];
+
+        expect(parse.type).toEqual("accentUnder");
+    });
+
+    it("should be grouped more tightly than supsubs", function() {
+        const parse = getParsed("\\underrightarrow x^2")[0];
+
+        expect(parse.type).toEqual("supsub");
+    });
+});
+
+describe("An under-accent builder", function() {
+    it("should not fail", function() {
+        expect("\\underrightarrow{x}").toBuild();
+        expect("\\underrightarrow{x}^2").toBuild();
+        expect("\\underrightarrow{x}_2").toBuild();
+        expect("\\underrightarrow{x}_2^2").toBuild();
+    });
+
+    it("should produce mords", function() {
+        expect(getBuilt("\\underrightarrow x")[0].classes).toContain("mord");
+        expect(getBuilt("\\underrightarrow +")[0].classes).toContain("mord");
+        expect(getBuilt("\\underrightarrow +")[0].classes).not.toContain("mbin");
+        expect(getBuilt("\\underrightarrow )^2")[0].classes).toContain("mord");
+        expect(getBuilt("\\underrightarrow )^2")[0].classes).not.toContain("mclose");
+    });
+});
+
+describe("An extensible arrow parser", function() {
+    it("should not fail", function() {
+        expect("\\xrightarrow{x}").toParse();
+        expect("\\xrightarrow{x^2}").toParse();
+        expect("\\xrightarrow{x}^2").toParse();
+        expect("\\xrightarrow x").toParse();
+        expect("\\xrightarrow[under]{over}").toParse();
+    });
+
+    it("should produce xArrow", function() {
+        const parse = getParsed("\\xrightarrow x")[0];
+
+        expect(parse.type).toEqual("xArrow");
+    });
+
+    it("should be grouped more tightly than supsubs", function() {
+        const parse = getParsed("\\xrightarrow x^2")[0];
+
+        expect(parse.type).toEqual("supsub");
+    });
+});
+
+describe("An extensible arrow builder", function() {
+    it("should not fail", function() {
+        expect("\\xrightarrow{x}").toBuild();
+        expect("\\xrightarrow{x}^2").toBuild();
+        expect("\\xrightarrow{x}_2").toBuild();
+        expect("\\xrightarrow{x}_2^2").toBuild();
+        expect("\\xrightarrow[under]{over}").toBuild();
+    });
+
+    it("should produce mrell", function() {
+        expect(getBuilt("\\xrightarrow x")[0].classes).toContain("mrel");
+        expect(getBuilt("\\xrightarrow [under]{over}")[0].classes).toContain("mrel");
+        expect(getBuilt("\\xrightarrow +")[0].classes).toContain("mrel");
+        expect(getBuilt("\\xrightarrow +")[0].classes).not.toContain("mbin");
+        expect(getBuilt("\\xrightarrow )^2")[0].classes).toContain("mrel");
+        expect(getBuilt("\\xrightarrow )^2")[0].classes).not.toContain("mclose");
+    });
+});
+
+describe("A horizontal brace parser", function() {
+    it("should not fail", function() {
+        expect("\\overbrace{x}").toParse();
+        expect("\\overbrace{x^2}").toParse();
+        expect("\\overbrace{x}^2").toParse();
+        expect("\\overbrace x").toParse();
+        expect("\\underbrace{x}_2").toParse();
+        expect("\\underbrace{x}_2^2").toParse();
+    });
+
+    it("should produce horizBrace", function() {
+        const parse = getParsed("\\overbrace x")[0];
+
+        expect(parse.type).toEqual("horizBrace");
+    });
+
+    it("should be grouped more tightly than supsubs", function() {
+        const parse = getParsed("\\overbrace x^2")[0];
+
+        expect(parse.type).toEqual("supsub");
+    });
+});
+
+describe("A horizontal brace builder", function() {
+    it("should not fail", function() {
+        expect("\\overbrace{x}").toBuild();
+        expect("\\overbrace{x}^2").toBuild();
+        expect("\\underbrace{x}_2").toBuild();
+        expect("\\underbrace{x}_2^2").toBuild();
+    });
+
+    it("should produce mords", function() {
+        expect(getBuilt("\\overbrace x")[0].classes).toContain("mord");
+        expect(getBuilt("\\overbrace{x}^2")[0].classes).toContain("mord");
+        expect(getBuilt("\\overbrace +")[0].classes).toContain("mord");
+        expect(getBuilt("\\overbrace +")[0].classes).not.toContain("mbin");
+        expect(getBuilt("\\overbrace )^2")[0].classes).toContain("mord");
+        expect(getBuilt("\\overbrace )^2")[0].classes).not.toContain("mclose");
+    });
+});
+
+describe("A boxed parser", function() {
+    it("should not fail", function() {
+        expect("\\boxed{x}").toParse();
+        expect("\\boxed{x^2}").toParse();
+        expect("\\boxed{x}^2").toParse();
+        expect("\\boxed x").toParse();
+    });
+
+    it("should produce enclose", function() {
+        const parse = getParsed("\\boxed x")[0];
+
+        expect(parse.type).toEqual("enclose");
+    });
+});
+
+describe("A boxed builder", function() {
+    it("should not fail", function() {
+        expect("\\boxed{x}").toBuild();
+        expect("\\boxed{x}^2").toBuild();
+        expect("\\boxed{x}_2").toBuild();
+        expect("\\boxed{x}_2^2").toBuild();
+    });
+
+    it("should produce mords", function() {
+        expect(getBuilt("\\boxed x")[0].classes).toContain("mord");
+        expect(getBuilt("\\boxed +")[0].classes).toContain("mord");
+        expect(getBuilt("\\boxed +")[0].classes).not.toContain("mbin");
+        expect(getBuilt("\\boxed )^2")[0].classes).toContain("mord");
+        expect(getBuilt("\\boxed )^2")[0].classes).not.toContain("mclose");
+    });
+});
+
+describe("A strike-through parser", function() {
+    it("should not fail", function() {
+        expect("\\cancel{x}").toParse();
+        expect("\\cancel{x^2}").toParse();
+        expect("\\cancel{x}^2").toParse();
+        expect("\\cancel x").toParse();
+    });
+
+    it("should produce enclose", function() {
+        const parse = getParsed("\\cancel x")[0];
+
+        expect(parse.type).toEqual("enclose");
+    });
+
+    it("should be grouped more tightly than supsubs", function() {
+        const parse = getParsed("\\cancel x^2")[0];
+
+        expect(parse.type).toEqual("supsub");
+    });
+});
+
+describe("A strike-through builder", function() {
+    it("should not fail", function() {
+        expect("\\cancel{x}").toBuild();
+        expect("\\cancel{x}^2").toBuild();
+        expect("\\cancel{x}_2").toBuild();
+        expect("\\cancel{x}_2^2").toBuild();
+        expect("\\sout{x}").toBuild();
+        expect("\\sout{x}^2").toBuild();
+        expect("\\sout{x}_2").toBuild();
+        expect("\\sout{x}_2^2").toBuild();
+    });
+
+    it("should produce mords", function() {
+        expect(getBuilt("\\cancel x")[0].classes).toContain("mord");
+        expect(getBuilt("\\cancel +")[0].classes).toContain("mord");
+        expect(getBuilt("\\cancel +")[0].classes).not.toContain("mbin");
+        expect(getBuilt("\\cancel )^2")[0].classes).toContain("mord");
+        expect(getBuilt("\\cancel )^2")[0].classes).not.toContain("mclose");
+    });
+});
+
 describe("A phantom parser", function() {
     it("should not fail", function() {
         expect("\\phantom{x}").toParse();

test/screenshotter/ss_data.yaml

@@ -42,6 +42,7 @@ BinCancellation: |
     \end{array}
 BinomTest: \dbinom{a}{b}\tbinom{a}{b}^{\binom{a}{b}+17}
 BoldSpacing: \mathbf{A}^2+\mathbf{B}_3*\mathscr{C}'
+Boxed: \boxed{F=ma} \quad \boxed{ac}\color{magenta}{\boxed{F}}\boxed{F=mg}
 Cases: |
     f(a,b)=\begin{cases}
         a+1&\text{if }b\text{ is odd} \\
@@ -72,6 +73,12 @@ DisplayStyle: |
     {\displaystyle\sqrt{x}}{\sqrt{x}}
     {\displaystyle \frac12}{\frac12}{\displaystyle x^1_2}{x^1_2}
 Exponents: a^{a^a_a}_{a^a_a}
+ExtensibleArrows: |
+    \begin{array}{l}
+        \xrightarrow[ab]{ABC} + \xRightarrow{ABC} \\
+        \xrightleftharpoons[ab]{ABC} + \xhookrightarrow[ab]{ABC} \\
+        \xtwoheadrightarrow{ABC} + \frac{\xrightarrow[ab]{ABC}}{\xrightarrow[ab]{ABC}} + \left\lvert\xrightarrow[ab]{ABC}\right\rvert
+    \end{array}
 FractionTest: \dfrac{a}{b}\frac{a}{b}\tfrac{a}{b}\;-\dfrac12\;1\tfrac12\;{1 \atop 2}
 Functions: \sin\cos\tan\ln\log
 Gathered: |
@@ -89,6 +96,7 @@ GroupMacros:
         \startExp: e^\bgroup
         \endExp: \egroup
     tex: \startExp a+b\endExp
+HorizontalBraces: \overbrace{\displaystyle{\oint_S{\vec E\cdot\hat n\,\mathrm d a}}}^\text{emf} = \underbrace{\frac{q_{\text{enc}}}{\varepsilon_0}}_{\text{charge}}
 KaTeX: \KaTeX
 Kern:
     tex: \frac{a\kern{1em}b}{c}a\kern{1em}b\kern{1ex}c\kern{-0.25em}d
@@ -104,6 +112,13 @@ LeftRightStyleSizing: |
 LimitControls: |
     \displaystyle\int\limits_2^3 3x^2\,dx + \sum\nolimits^n_{i=1}i +
     \textstyle\int\limits_x^y z
+LowerAccent: |
+    \begin{matrix}
+        \underleftarrow{AB} \quad \underrightarrow{AB} \quad \underleftrightarrow{AB} \quad \undergroup{AB} \\
+        \underlinesegment{AB} \quad \undertilde{AB}  \quad \color{green}{\underrightarrow{AB}} \\
+        \underrightarrow{F} + \underrightarrow{AB} + \underrightarrow{AB}^2 + \underrightarrow{AB}_2 \\
+        \frac{\underrightarrow{AB}}{\underrightarrow{AB}} + \sqrt{\underrightarrow{AB}} + \left\lvert\underrightarrow{AB}\right\rvert
+    \end{matrix}
 MathAtom: a\mathrel{\mathop{=}\limits^{\blue ?}}b
 MathAtom2: \mathop{\overline{\mathrm{lim}}}\limits_{x\to\infty}f(x)
 MathDefaultFonts: Ax2k\breve{a}\omega\Omega\imath+\KaTeX
@@ -168,6 +183,21 @@ Sqrt: |
 SqrtRoot: |
     1+\sqrt[3]{2}+\sqrt[1923^234]{2^{2^{2^{2^{2^{2^{2^{2^{2^{2^{2^2}}}}}}}}}}}
 StackRel: a \stackrel{?}{=} b \stackrel{\text{def}}{=} c
+StretchyAccent: |
+    \begin{array}{l}
+        \overrightarrow{AB} \quad \overleftarrow{AB} \quad \Overrightarrow{AB} \quad \overleftrightarrow{AB} \quad \overgroup{AB} \\
+        \overlinesegment{AB} \quad \overleftharpoon{AB} \quad \overrightharpoon{AB} \quad \color{red}{\overrightarrow{AB}} \quad \widehat{\theta} \widetilde{A} \\
+        \widehat{AB} \quad \widehat{ABC} \quad \widetilde{AB} \quad \widetilde{ABC} \\
+        \overrightarrow{F} + \overrightarrow{AB} + \overrightarrow{F}^2 + \overrightarrow{F}_2 + \overrightarrow{F}_1^2 \\
+        \overrightarrow{AB}^2+\frac{\overrightarrow{AB}}{\overrightarrow{AB}} + \sqrt{\overrightarrow{AB}} + \left\lvert\overrightarrow{AB}\right\rvert
+    \end{array}
+StrikeThrough: |
+    \begin{array}{l}
+        \cancel x \quad \cancel{2B} + \bcancel 5 +\bcancel{5ay} \\
+        \sout{5ab} + \sout{5ABC} + \xcancel{\oint_S{\vec E\cdot\hat n\,\mathrm d a}} \\
+        \frac{x+\cancel B}{x+\cancel x} + \frac{x+\cancel y}{x} + \cancel{B}_1^2 + \cancel{B^2} \\
+        \left\lvert\cancel{ac}\right\rvert
+    \end{array}
 StyleSpacing: \scriptstyle ab\;cd
 StyleSwitching: a\cdot b\scriptstyle a\cdot ba\textstyle\cdot ba\scriptstyle\cdot b
 SupSubCharacterBox: a_2f_2{f}_2{aa}_2{af}_2\mathbf{y}_Ay_A