Add support for \lparen and \rparen delimiters. (#1741)

* Add support for `\lparen` and `\rparen` delimiters.

* Add missing math delimiter. Fix alphabetic order.

* Add test.

* Add spaces between parenthesis and square brackets.

docs/support_table.md

@@ -587,6 +587,7 @@ table td {
 |\lor|$\lor$||
 |\lower|<span style="color:firebrick;">Not supported</span>||
 |\lozenge|$\lozenge$||
+|\lparen|$\lparen$||
 |\Lrarr|$\Lrarr$||
 |\lrArr|$\lrArr$||
 |\lrarr|$\lrarr$||
@@ -864,6 +865,7 @@ table td {
 |\rmoustache|$\rmoustache$||
 |\root|<span style="color:firebrick;">Not supported</span>||
 |\rotatebox|<span style="color:firebrick;">Not supported</span>|[Issue #681](https://github.com/Khan/KaTeX/issues/681)|
+|\rparen|$\rparen$||
 |\rq|$\rq$||
 |\Rrightarrow|$\Rrightarrow$||
 |\Rsh|$\Rsh$||

docs/supported.md

@@ -53,14 +53,14 @@ See also [letters](#letters)
 
 ||||||
 |:-----------------------------------|:---------------------------------------|:----------|:-------------------------------------------------------|:-----
-|$( )$ `( )` |$\lt~\gt$ `\lt \gt` |$⌈~⌉$ `⌈ ⌉`|$\lceil~\rceil$ `\lceil`<br>$~~~~~$`\rceil`  |$\uparrow$ `\uparrow`
-|$[ ]$ `[ ]` |$\lbrack~\rbrack$ `\lbrack`<br>$~~~~$`\rbrack`|$⌊~⌋$ `⌊ ⌋`|$\lfloor~\rfloor$ `\lfloor`<br>$~~~~~$`\rfloor` |$\downarrow$ `\downarrow`
+|$(~)$ `( )` |$\lparen~\rparen$ `\lparen`<br>$~~~~$`\rparen`|$⌈~⌉$ `⌈ ⌉`|$\lceil~\rceil$ `\lceil`<br>$~~~~~$`\rceil`  |$\uparrow$ `\uparrow`
+|$[~]$ `[ ]` |$\lbrack~\rbrack$ `\lbrack`<br>$~~~~$`\rbrack`|$⌊~⌋$ `⌊ ⌋`|$\lfloor~\rfloor$ `\lfloor`<br>$~~~~~$`\rfloor` |$\downarrow$ `\downarrow`
 |$\{ \}$ `\{ \}`|$\lbrace \rbrace$ `\lbrace`<br>$~~~~$`\rbrace`|$⎰⎱$ `⎰⎱`  |$\lmoustache \rmoustache$ `\lmoustache`<br>$~~~~$`\rmoustache`|$\updownarrow$ `\updownarrow`
 |$⟨~⟩$ `⟨ ⟩` |$\langle~\rangle$ `\langle`<br>$~~~~$`\rangle`|$⟮~⟯$ `⟮ ⟯`|$\lgroup~\rgroup$ `\lgroup`<br>$~~~~~$`\rgroup` |$\Uparrow$ `\Uparrow`
 |$\vert$ <code>&#124;</code> |$\vert$ `\vert` |$┌ ┐$ `┌ ┐`|$\ulcorner \urcorner$ `\ulcorner`<br>$~~~~$`\urcorner`  |$\Downarrow$ `\Downarrow`
 |$\Vert$ <code>&#92;&#124;</code> |$\Vert$ `\Vert` |$└ ┘$ `└ ┘`|$\llcorner \lrcorner$ `\llcorner`<br>$~~~~$`\lrcorner`  |$\Updownarrow$ `\Updownarrow`
 |$\lvert~\rvert$ `\lvert`<br>$~~~~$`\rvert`|$\lVert~\rVert$ `\lVert`<br>$~~~~~$`\rVert` |`\left.`|  `\right.` |$\backslash$ `\backslash`
-|$\lang~\rang$ `\lang`<br>$~~~~$`\rang`
+|$\lang~\rang$ `\lang`<br>$~~~~$`\rang`|$\lt~\gt$ `\lt \gt`|
 
 **Delimiter Sizing**
 

src/delimiter.js

@@ -245,12 +245,12 @@ const makeStackedDelim = function(
         top = "\u23a4";
         repeat = bottom = "\u23a5";
         font = "Size4-Regular";
-    } else if (delim === "(") {
+    } else if (delim === "(" || delim === "\\lparen") {
         top = "\u239b";
         repeat = "\u239c";
         bottom = "\u239d";
         font = "Size4-Regular";
-    } else if (delim === ")") {
+    } else if (delim === ")" || delim === "\\rparen") {
         top = "\u239e";
         repeat = "\u239f";
         bottom = "\u23a0";
@@ -489,7 +489,8 @@ const makeSqrtImage = function(
 // There are three kinds of delimiters, delimiters that stack when they become
 // too large
 const stackLargeDelimiters = [
-    "(", ")", "[", "\\lbrack", "]", "\\rbrack",
+    "(", "\\lparen", ")", "\\rparen",
+    "[", "\\lbrack", "]", "\\rbrack",
     "\\{", "\\lbrace", "\\}", "\\rbrace",
     "\\lfloor", "\\rfloor", "\u230a", "\u230b",
     "\\lceil", "\\rceil", "\u2308", "\u2309",

src/functions/delimsizing.js

@@ -35,7 +35,8 @@ const delimiterSizes = {
 };
 
 const delimiters = [
-    "(", ")", "[", "\\lbrack", "]", "\\rbrack",
+    "(", "\\lparen", ")", "\\rparen",
+    "[", "\\lbrack", "]", "\\rbrack",
     "\\{", "\\lbrace", "\\}", "\\rbrace",
     "\\lfloor", "\\rfloor", "\u230a", "\u230b",
     "\\lceil", "\\rceil", "\u2308", "\u2309",

src/symbols.js

@@ -625,6 +625,8 @@ defineSymbol(math, main, open, "[", "\\lbrack");
 defineSymbol(text, main, textord, "[", "\\lbrack");
 defineSymbol(math, main, close, "]", "\\rbrack");
 defineSymbol(text, main, textord, "]", "\\rbrack");
+defineSymbol(math, main, open, "(", "\\lparen");
+defineSymbol(math, main, close, ")", "\\rparen");
 defineSymbol(text, main, textord, "<", "\\textless"); // in T1 fontenc
 defineSymbol(text, main, textord, ">", "\\textgreater"); // in T1 fontenc
 defineSymbol(math, main, open, "\u230a", "\\lfloor", true);

test/katex-spec.js

@@ -1198,6 +1198,7 @@ describe("left/right builder", () => {
     const cases = [
         [r`\left\langle \right\rangle`, r`\left< \right>`],
         [r`\left\langle \right\rangle`, '\\left\u27e8 \\right\u27e9'],
+        [r`\left\lparen \right\rparen`, r`\left( \right)`],
     ];
 
     for (const [actual, expected] of cases) {