Method formatErrors

src/core/parser.js:41–88

(errors)

    }

    static formatErrors(errors) {
        if (!errors.length) return "";
        var source = errors[0].source;
        var lines = source.split("\n");

        var byLine = new Map();
        for (var e of errors) {
            var lineIdx = e.token?.line ? e.token.line - 1 : lines.length - 1;
            if (!byLine.has(lineIdx)) byLine.set(lineIdx, []);
            byLine.get(lineIdx).push(e);
        }

        var maxLine = Math.max(...byLine.keys()) + 1;
        var gutter = String(maxLine).length;
        var pad = " ".repeat(gutter + 5);
        var sortedLines = [...byLine.entries()].sort((a, b) => a[0] - b[0]);
        var prevLineIdx = -1;
        var out = "";

        for (var [lineIdx, lineErrors] of sortedLines) {
            if (prevLineIdx !== -1 && lineIdx > prevLineIdx + 1) {
                out += " ".repeat(gutter + 1) + "...\n";
            } else if (prevLineIdx === -1 && lineIdx > 0) {
                out += " ".repeat(gutter + 1) + "...\n";
            }
            prevLineIdx = lineIdx;

            var lineNum = String(lineIdx + 1).padStart(gutter);
            var contextLine = lines[lineIdx] || "";
            out += "  " + lineNum + " | " + contextLine + "\n";

            lineErrors.sort((a, b) => (a.column || 0) - (b.column || 0));

            var underlineChars = Array(contextLine.length + 10).fill(" ");
            for (var e of lineErrors) {
                var col = e.token?.line ? e.token.column : Math.max(0, contextLine.length - 1);
                var len = Math.max(1, e.token?.value?.length || 1);
                for (var i = 0; i < len; i++) underlineChars[col + i] = "^";
            }
            out += pad + underlineChars.join("").trimEnd() + "\n";

            for (var e of lineErrors) {
                var col = e.token?.line ? e.token.column : 0;
                out += pad + " ".repeat(col) + e.message + "\n";
            }
        }
        return out;
    }

    // ===========================
    // Token delegation methods