Merge pull request #2328 from alixander/latex-backslash

d2latex: fix latex backslashes doubling

ci/release/changelogs/next.md

@@ -30,3 +30,4 @@
 - Sequence diagrams: fixes alignment of notes when self messages are above it [#2264](https://github.com/terrastruct/d2/pull/2264)
 - Null: fixes `null`ing a connection with absolute syntax [#2318](https://github.com/terrastruct/d2/issues/2318)
 - Gradients: works with connection fills [#2326](https://github.com/terrastruct/d2/pull/2326)
+- Latex: fixes backslashes doubling on successive parses [#2328](https://github.com/terrastruct/d2/pull/2328)

d2parser/parse.go

@@ -1480,12 +1480,6 @@ func (p *parser) parseBlockString() *d2ast.BlockString {
 		}
 
 		if r != endHint {
-			if (bs.Tag == "latex" || bs.Tag == "tex") && r == '\\' {
-				// For LaTeX, where single backslash is common, we escape it so that users don't have to write double the backslashes
-				sb.WriteRune('\\')
-				sb.WriteRune('\\')
-				continue
-			}
 			sb.WriteRune(r)
 			continue
 		}

d2renderers/d2latex/latex.go

@@ -6,6 +6,7 @@ import (
 	"math"
 	"regexp"
 	"strconv"
+	"strings"
 
 	"oss.terrastruct.com/d2/lib/jsrunner"
 	"oss.terrastruct.com/util-go/xdefer"
@@ -28,6 +29,7 @@ var svgRe = regexp.MustCompile(`<svg[^>]+width="([0-9\.]+)ex" height="([0-9\.]+)
 
 func Render(s string) (_ string, err error) {
 	defer xdefer.Errorf(&err, "latex failed to parse")
+	s = doubleBackslashes(s)
 	runner := jsrunner.NewJSRunner()
 
 	if _, err := runner.RunString(polyfillsJS); err != nil {
@@ -82,3 +84,15 @@ func Measure(s string) (width, height int, err error) {
 
 	return int(math.Ceil(wf * float64(pxPerEx))), int(math.Ceil(hf * float64(pxPerEx))), nil
 }
+
+func doubleBackslashes(s string) string {
+	var result strings.Builder
+	for i := 0; i < len(s); i++ {
+		if s[i] == '\\' {
+			result.WriteString("\\\\")
+		} else {
+			result.WriteByte(s[i])
+		}
+	}
+	return result.String()
+}

d2renderers/d2latex/latex_test.go

@@ -8,7 +8,7 @@ import (
 func TestRender(t *testing.T) {
 	txts := []string{
 		`a + b = c`,
-		`\\frac{1}{2}`,
+		`\frac{1}{2}`,
 		`a + b
 = c
 `,
@@ -24,10 +24,3 @@ func TestRender(t *testing.T) {
 		}
 	}
 }
-
-func TestRenderError(t *testing.T) {
-	_, err := Render(`\frac{1}{2}`)
-	if err == nil {
-		t.Fatal("expected to error on invalid latex syntax")
-	}
-}

e2etests/testdata/regression/grid_with_latex/dagre/board.exp.json

@@ -333,7 +333,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\lim_{h \\\\rightarrow 0 } \\\\frac{f(x+h)-f(x)}{h}",
+      "label": "\\lim_{h \\rightarrow 0 } \\frac{f(x+h)-f(x)}{h}",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",

e2etests/testdata/regression/grid_with_latex/elk/board.exp.json

@@ -333,7 +333,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\lim_{h \\\\rightarrow 0 } \\\\frac{f(x+h)-f(x)}{h}",
+      "label": "\\lim_{h \\rightarrow 0 } \\frac{f(x+h)-f(x)}{h}",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",

e2etests/testdata/stable/grid_outside_labels/dagre/board.exp.json

@@ -123,7 +123,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\begin{CD} B @>{\\\\text{very long label}}>> C S^{{\\\\mathcal{W}}_\\\\Lambda}\\\\otimes T @>j>> T\\\\\\\\ @VVV V \\\\end{CD}",
+      "label": "\\begin{CD} B @>{\\text{very long label}}>> C S^{{\\mathcal{W}}_\\Lambda}\\otimes T @>j>> T\\\\ @VVV V \\end{CD}",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -206,7 +206,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\bra{a}\\\\ket{b}",
+      "label": "\\bra{a}\\ket{b}",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -289,7 +289,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\cancel{Culture + 5}",
+      "label": "\\cancel{Culture + 5}",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -384,7 +384,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\textcolor{red}{y} = \\\\textcolor{green}{\\\\sin} x",
+      "label": "\\textcolor{red}{y} = \\textcolor{green}{\\sin} x",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -467,7 +467,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\lambda = 10.6\\\\,\\\\micro\\\\mathrm{m}",
+      "label": "\\lambda = 10.6\\,\\micro\\mathrm{m}",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -550,7 +550,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\ce{SO4^2- + Ba^2+ -> BaSO4 v}",
+      "label": "\\ce{SO4^2- + Ba^2+ -> BaSO4 v}",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -633,7 +633,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\var{F[g(x)]}\n\\\\dd(\\\\cos\\\\theta)",
+      "label": "\\var{F[g(x)]}\n\\dd(\\cos\\theta)",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -716,7 +716,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\displaylines{x = a + b \\\\\\\\ y = b + c}\n\\\\sum_{k=1}^{n} h_{k} \\\\int_{0}^{1} \\\\bigl(\\\\partial_{k} f(x_{k-1}+t h_{k} e_{k}) -\\\\partial_{k} f(a)\\\\bigr) \\\\,dt",
+      "label": "\\displaylines{x = a + b \\\\ y = b + c}\n\\sum_{k=1}^{n} h_{k} \\int_{0}^{1} \\bigl(\\partial_{k} f(x_{k-1}+t h_{k} e_{k}) -\\partial_{k} f(a)\\bigr) \\,dt",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -799,7 +799,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\min_{ \\\\mathclap{\\\\substack{ x \\\\in \\\\mathbb{R}^n \\\\ x \\\\geq 0 \\\\ Ax \\\\leq b }}} c^T x",
+      "label": "\\min_{ \\mathclap{\\substack{ x \\in \\mathbb{R}^n \\ x \\geq 0 \\ Ax \\leq b }}} c^T x",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",

e2etests/testdata/stable/grid_outside_labels/elk/board.exp.json

@@ -123,7 +123,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\begin{CD} B @>{\\\\text{very long label}}>> C S^{{\\\\mathcal{W}}_\\\\Lambda}\\\\otimes T @>j>> T\\\\\\\\ @VVV V \\\\end{CD}",
+      "label": "\\begin{CD} B @>{\\text{very long label}}>> C S^{{\\mathcal{W}}_\\Lambda}\\otimes T @>j>> T\\\\ @VVV V \\end{CD}",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -206,7 +206,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\bra{a}\\\\ket{b}",
+      "label": "\\bra{a}\\ket{b}",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -289,7 +289,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\cancel{Culture + 5}",
+      "label": "\\cancel{Culture + 5}",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -384,7 +384,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\textcolor{red}{y} = \\\\textcolor{green}{\\\\sin} x",
+      "label": "\\textcolor{red}{y} = \\textcolor{green}{\\sin} x",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -467,7 +467,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\lambda = 10.6\\\\,\\\\micro\\\\mathrm{m}",
+      "label": "\\lambda = 10.6\\,\\micro\\mathrm{m}",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -550,7 +550,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\ce{SO4^2- + Ba^2+ -> BaSO4 v}",
+      "label": "\\ce{SO4^2- + Ba^2+ -> BaSO4 v}",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -633,7 +633,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\var{F[g(x)]}\n\\\\dd(\\\\cos\\\\theta)",
+      "label": "\\var{F[g(x)]}\n\\dd(\\cos\\theta)",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -716,7 +716,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\displaylines{x = a + b \\\\\\\\ y = b + c}\n\\\\sum_{k=1}^{n} h_{k} \\\\int_{0}^{1} \\\\bigl(\\\\partial_{k} f(x_{k-1}+t h_{k} e_{k}) -\\\\partial_{k} f(a)\\\\bigr) \\\\,dt",
+      "label": "\\displaylines{x = a + b \\\\ y = b + c}\n\\sum_{k=1}^{n} h_{k} \\int_{0}^{1} \\bigl(\\partial_{k} f(x_{k-1}+t h_{k} e_{k}) -\\partial_{k} f(a)\\bigr) \\,dt",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -799,7 +799,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\min_{ \\\\mathclap{\\\\substack{ x \\\\in \\\\mathbb{R}^n \\\\ x \\\\geq 0 \\\\ Ax \\\\leq b }}} c^T x",
+      "label": "\\min_{ \\mathclap{\\substack{ x \\in \\mathbb{R}^n \\ x \\geq 0 \\ Ax \\leq b }}} c^T x",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",

e2etests/testdata/stable/latex/dagre/board.exp.json

@@ -39,7 +39,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\Huge{\\\\frac{\\\\alpha g^2}{\\\\omega^5} e^{[ -0.74\\\\bigl\\\\{\\\\frac{\\\\omega U_\\\\omega 19.5}{g}\\\\bigr\\\\}^{\\\\!-4}\\\\,]}}",
+      "label": "\\Huge{\\frac{\\alpha g^2}{\\omega^5} e^{[ -0.74\\bigl\\{\\frac{\\omega U_\\omega 19.5}{g}\\bigr\\}^{\\!-4}\\,]}}",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -121,7 +121,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "gibberish\\\\; math:\\\\sum_{i=0}^\\\\infty i^2",
+      "label": "gibberish\\; math:\\sum_{i=0}^\\infty i^2",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -330,7 +330,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\min_{ \\\\mathclap{\\\\substack{ x \\\\in \\\\mathbb{R}^n \\\\ x \\\\geq 0 \\\\ Ax \\\\leq b }}} c^T x",
+      "label": "\\min_{ \\mathclap{\\substack{ x \\in \\mathbb{R}^n \\ x \\geq 0 \\ Ax \\leq b }}} c^T x",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",

e2etests/testdata/stable/latex/elk/board.exp.json

@@ -39,7 +39,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\Huge{\\\\frac{\\\\alpha g^2}{\\\\omega^5} e^{[ -0.74\\\\bigl\\\\{\\\\frac{\\\\omega U_\\\\omega 19.5}{g}\\\\bigr\\\\}^{\\\\!-4}\\\\,]}}",
+      "label": "\\Huge{\\frac{\\alpha g^2}{\\omega^5} e^{[ -0.74\\bigl\\{\\frac{\\omega U_\\omega 19.5}{g}\\bigr\\}^{\\!-4}\\,]}}",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -121,7 +121,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "gibberish\\\\; math:\\\\sum_{i=0}^\\\\infty i^2",
+      "label": "gibberish\\; math:\\sum_{i=0}^\\infty i^2",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",
@@ -330,7 +330,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\min_{ \\\\mathclap{\\\\substack{ x \\\\in \\\\mathbb{R}^n \\\\ x \\\\geq 0 \\\\ Ax \\\\leq b }}} c^T x",
+      "label": "\\min_{ \\mathclap{\\substack{ x \\in \\mathbb{R}^n \\ x \\geq 0 \\ Ax \\leq b }}} c^T x",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",

e2etests/testdata/themes/dark_terrastruct_flagship/dagre/board.exp.json

@@ -833,7 +833,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\displaylines{x = a + b \\\\\\\\ y = b + c}\n\\\\sum_{k=1}^{n} h_{k} \\\\int_{0}^{1} \\\\bigl(\\\\partial_{k} f(x_{k-1}+t h_{k} e_{k}) -\\\\partial_{k} f(a)\\\\bigr) \\\\,dt",
+      "label": "\\displaylines{x = a + b \\\\ y = b + c}\n\\sum_{k=1}^{n} h_{k} \\int_{0}^{1} \\bigl(\\partial_{k} f(x_{k-1}+t h_{k} e_{k}) -\\partial_{k} f(a)\\bigr) \\,dt",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",

e2etests/testdata/themes/dark_terrastruct_flagship/elk/board.exp.json

@@ -833,7 +833,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\displaylines{x = a + b \\\\\\\\ y = b + c}\n\\\\sum_{k=1}^{n} h_{k} \\\\int_{0}^{1} \\\\bigl(\\\\partial_{k} f(x_{k-1}+t h_{k} e_{k}) -\\\\partial_{k} f(a)\\\\bigr) \\\\,dt",
+      "label": "\\displaylines{x = a + b \\\\ y = b + c}\n\\sum_{k=1}^{n} h_{k} \\int_{0}^{1} \\bigl(\\partial_{k} f(x_{k-1}+t h_{k} e_{k}) -\\partial_{k} f(a)\\bigr) \\,dt",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",

e2etests/testdata/themes/terminal/dagre/board.exp.json

@@ -837,7 +837,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\displaylines{x = a + b \\\\\\\\ y = b + c}\n\\\\sum_{k=1}^{n} h_{k} \\\\int_{0}^{1} \\\\bigl(\\\\partial_{k} f(x_{k-1}+t h_{k} e_{k}) -\\\\partial_{k} f(a)\\\\bigr) \\\\,dt",
+      "label": "\\displaylines{x = a + b \\\\ y = b + c}\n\\sum_{k=1}^{n} h_{k} \\int_{0}^{1} \\bigl(\\partial_{k} f(x_{k-1}+t h_{k} e_{k}) -\\partial_{k} f(a)\\bigr) \\,dt",
       "fontSize": 16,
       "fontFamily": "mono",
       "language": "latex",

e2etests/testdata/themes/terminal/elk/board.exp.json

@@ -837,7 +837,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\displaylines{x = a + b \\\\\\\\ y = b + c}\n\\\\sum_{k=1}^{n} h_{k} \\\\int_{0}^{1} \\\\bigl(\\\\partial_{k} f(x_{k-1}+t h_{k} e_{k}) -\\\\partial_{k} f(a)\\\\bigr) \\\\,dt",
+      "label": "\\displaylines{x = a + b \\\\ y = b + c}\n\\sum_{k=1}^{n} h_{k} \\int_{0}^{1} \\bigl(\\partial_{k} f(x_{k-1}+t h_{k} e_{k}) -\\partial_{k} f(a)\\bigr) \\,dt",
       "fontSize": 16,
       "fontFamily": "mono",
       "language": "latex",

e2etests/testdata/txtar/single-backslash-latex/dagre/board.exp.json

@@ -81,7 +81,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\begin{equation} \\\\label{eq1}\n\\\\begin{split}\nA & = \\\\frac{\\\\\\\\pi r^2}{2} \\\\\\\\\n & = \\\\frac{1}{2} \\\\pi r^2\n\\\\end{split}\n\\\\end{equation}",
+      "label": "\\begin{equation} \\label{eq1}\n\\begin{split}\nA & = \\frac{\\\\pi r^2}{2} \\\\\n & = \\frac{1}{2} \\pi r^2\n\\end{split}\n\\end{equation}",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",

e2etests/testdata/txtar/single-backslash-latex/elk/board.exp.json

@@ -81,7 +81,7 @@
       "fields": null,
       "methods": null,
       "columns": null,
-      "label": "\\\\begin{equation} \\\\label{eq1}\n\\\\begin{split}\nA & = \\\\frac{\\\\\\\\pi r^2}{2} \\\\\\\\\n & = \\\\frac{1}{2} \\\\pi r^2\n\\\\end{split}\n\\\\end{equation}",
+      "label": "\\begin{equation} \\label{eq1}\n\\begin{split}\nA & = \\frac{\\\\pi r^2}{2} \\\\\n & = \\frac{1}{2} \\pi r^2\n\\end{split}\n\\end{equation}",
       "fontSize": 16,
       "fontFamily": "DEFAULT",
       "language": "latex",