feat: \dddot and \ddddot support (#3834)

edemaine · web-flow · commit bda35cdb0a6b · 2024-12-08T17:05:00.000-05:00
* feat: \dddot and \ddddot support Fixes #2744 (though italic correction is off) * Document \dddot and \ddddot
diff --git a/docs/support_table.md b/docs/support_table.md
@@ -314,8 +314,8 @@ use `\ce` instead|
 |{dcases}|$\begin{dcases}a&\text{if }b\\c&\text{if }d\end{dcases}$|`\begin{dcases}`<br>&nbsp;&nbsp;&nbsp;`a &\text{if } b  \\`<br>&nbsp;&nbsp;&nbsp;`c &\text{if } d`<br>`\end{dcases}`|
 |\ddag|$\ddag$||
 |\ddagger|$\ddagger$||
-|\ddddot|<span style="color:firebrick;">Not supported</span>||
-|\dddot|<span style="color:firebrick;">Not supported</span>||
+|\ddddot|$\ddddot x$|`\ddddot x`|
+|\dddot|$\dddot x$|`\dddot x`|
 |\ddot|$\ddot x$|`\ddot x`|
 |\ddots|$\ddots$||
 |\DeclareMathOperator|<span style="color:firebrick;">Not supported</span>||
diff --git a/docs/supported.md b/docs/supported.md
@@ -31,9 +31,10 @@ table td {
 |$\check{a}$ `\check{a}`|$\overleftharpoon{ac}$ `\overleftharpoon{ac}`  |$\overrightharpoon{ac}$ `\overrightharpoon{ac}`
 |$\dot{a}$ `\dot{a}` |$\overleftrightarrow{AB}$ `\overleftrightarrow{AB}`  |$\overbrace{AB}$ `\overbrace{AB}`
 |$\ddot{a}$ `\ddot{a}`  |$\underleftrightarrow{AB}$ `\underleftrightarrow{AB}`|$\underbrace{AB}$ `\underbrace{AB}`
-|$\grave{a}$ `\grave{a}`|$\overline{AB}$ `\overline{AB}` |$\overlinesegment{AB}$ `\overlinesegment{AB}`
-|$\hat{\theta}$ `\hat{\theta}`|$\underline{AB}$ `\underline{AB}`  |$\underlinesegment{AB}$ `\underlinesegment{AB}`
-|$\widehat{ac}$ `\widehat{ac}`|$\widecheck{ac}$ `\widecheck{ac}`  |$\underbar{X}$ `\underbar{X}`
+|$\dddot{a}$ `\dddot{a}`|$\overline{AB}$ `\overline{AB}` |$\overlinesegment{AB}$ `\overlinesegment{AB}`
+|$\ddddot{a}$ `\ddddot{a}`|$\underline{AB}$ `\underline{AB}`  |$\underlinesegment{AB}$ `\underlinesegment{AB}`
+|$\grave{a}$ `\grave{a}`|$\widecheck{ac}$ `\widecheck{ac}`  |$\underbar{X}$ `\underbar{X}`
+|$\hat{\theta}$ `\hat{\theta}`|$\widehat{ac}$ `\widehat{ac}`||
 
 ***Accent functions inside \\text{…}***
 
diff --git a/src/macros.js b/src/macros.js
@@ -380,6 +380,12 @@ defineMacro("\\iff", "\\DOTSB\\;\\Longleftrightarrow\\;");
 defineMacro("\\implies", "\\DOTSB\\;\\Longrightarrow\\;");
 defineMacro("\\impliedby", "\\DOTSB\\;\\Longleftarrow\\;");
 
+// \def\dddot#1{{\mathop{#1}\limits^{\vbox to-1.4\ex@{\kern-\tw@\ex@
+//  \hbox{\normalfont ...}\vss}}}}
+// We use \overset which avoids the vertical shift of \mathop.
+defineMacro("\\dddot", "{\\overset{\\raisebox{-0.1ex}{\\normalsize ...}}{#1}}");
+defineMacro("\\ddddot", "{\\overset{\\raisebox{-0.1ex}{\\normalsize ....}}{#1}}");
+
 // AMSMath's automatic \dots, based on \mdots@@ macro.
 const dotsByToken = {
     ',': '\\dotsc',
