feat: Add a macro translator.

main.ts

@@ -8,9 +8,12 @@ import {
 	PseudocodeBlockInit,
 	BLOCK_NAME,
 } from "src/setting";
+import {
+	translateUnsupportedMacrosPerf,
+	checkTranslatedMacros,
+} from "src/latex_translator";
 
 import * as pseudocode from "pseudocode";
-import * as katex from "katex";
 
 export default class PseudocodePlugin extends Plugin {
 	settings: PseudocodeSettings;
@@ -93,8 +96,12 @@ export default class PseudocodePlugin extends Plugin {
 		}
 
 		try {
-			katex.renderToString(this.preamble);
-			console.log("Preamble file loaded.");
+			this.preamble = translateUnsupportedMacrosPerf(this.preamble);
+			this.preamble = checkTranslatedMacros(this.preamble);
+			console.log("Loaded preamble:\n" + this.preamble);
+			console.log(
+				"Preamble file loaded. You can check the detail in console."
+			);
 			if (this.settings.preambleLoadedNotice) {
 				new Notice("Pseudocode Plugin: Preamble file loaded.");
 			}

src/latex_translator.ts

@@ -0,0 +1,69 @@
+import * as katex from "katex";
+
+export function translateUnsupportedMacros(input: string): string {
+	// handle \DeclarePairedDelimiter
+	let output = input.replace(
+		/\\DeclarePairedDelimiter\{(.*?)\}\{(.*?)\}\{(.*?)\}/g,
+		"\\newcommand{$1}[1]{\\left$2 #1 \\right$3}"
+	);
+
+	// handle \DeclareMathOperator
+	output = output.replace(
+		/\\DeclareMathOperator\*\{(.*?)\}\{(.*?)\}/g,
+		"\\newcommand{$1}{\\mathop{\\mathrm{$2}}}"
+	);
+	output = output.replace(
+		/\\DeclareMathOperator\{(.*?)\}\{(.*?)\}/g,
+		"\\newcommand{$1}{\\mathop{\\mathrm{$2}}}"
+	);
+	return output;
+}
+
+// This is a performance improvement for translateUnsupportedMacros
+export function translateUnsupportedMacrosPerf(input: string): string {
+	const stripped = input
+		.replace(/(?<!\\)%.*/gm, "")
+		.split("\n")
+		.filter((line) => line.trim() !== "")
+		.join("\n");
+
+	return stripped.replace(
+		/(\\DeclarePairedDelimiter\{(.*?)\}\{(.*?)\}\{(.*?)\})|(\\DeclareMathOperator\*\{(.*?)\}\{(.*?)\})|(\\DeclareMathOperator\{(.*?)\}\{(.*?)\})/g,
+		(match, p1, p2, p3, p4, p5, p6, p7, p8, p9, p10) => {
+			if (p1) {
+				// It's a \DeclarePairedDelimiter
+				return `\\newcommand{${p2}}[1]{\\left${p3} #1 \\right${p4}}`;
+			} else if (p5) {
+				// It's a \DeclareMathOperator*
+				return `\\newcommand{${p6}}{\\mathop{\\mathrm{${p7}}}}`;
+			} else if (p8) {
+				// It's a \DeclareMathOperator
+				return `\\newcommand{${p9}}{\\mathop{\\mathrm{${p10}}}}`;
+			} else {
+				// This should never happen if the regex is correct
+				console.error(`Unexpected match: ${match}`);
+				return match;
+			}
+		}
+	);
+}
+
+export function checkTranslatedMacros(input: string): string {
+	const lines = input.split("\n");
+	for (let i = 0; i < lines.length; i++) {
+		try {
+			katex.renderToString(lines[i]);
+		} catch (error) {
+			if (
+				error instanceof katex.ParseError &&
+				/redefine/.test(error.message)
+			) {
+				lines[i] = lines[i].replace("\\newcommand", "\\renewcommand");
+				console.log(`Redefining ${lines[i]}`);
+			} else {
+				throw error;
+			}
+		}
+	}
+	return lines.join("\n");
+}