1 files changed, 36 insertions, 0 deletions
diff --git a/bundle/src/ansi.js b/bundle/src/ansi.js
new file mode 100644
index 0000000..66173ea
--- /dev/null
+++ b/bundle/src/ansi.js
@@ -0,0 +1,36 @@
+// Splits terminal text into runs styled by SGR escape sequences, keeping the
+// style and any sequence cut off at a chunk boundary for the next chunk.
+// Handles reset, bold and the 16 foreground colors; drops other sequences.
+const names = ['Black', 'Red', 'Green', 'Yellow', 'Blue', 'Magenta', 'Cyan', 'White'];
+const sequence = /\x1b\[([0-?]*)[ -/]*([@-~])/g;
+const unfinished = /\x1b(\[[0-?]*[ -/]*)?$/;
+
+export function createAnsiParser() {
+	let bold = false;
+	let color = null;
+	let rest = '';
+	return text => {
+		text = rest + text;
+		const cut = text.match(unfinished);
+		rest = cut ? cut[0] : '';
+		if (cut) text = text.slice(0, cut.index);
+		const runs = [];
+		let start = 0;
+		for (const match of text.matchAll(sequence)) {
+			if (match.index > start) runs.push({ text: text.slice(start, match.index), bold, color });
+			start = match.index + match[0].length;
+			if (match[2] !== 'm') continue;
+			for (const parameter of match[1].split(';')) {
+				const code = Number(parameter || 0);
+				if (code === 0) { bold = false; color = null; }
+				else if (code === 1) bold = true;
+				else if (code === 22) bold = false;
+				else if (code === 39) color = null;
+				else if (code >= 30 && code <= 37) color = `terminal.ansi${names[code - 30]}`;
+				else if (code >= 90 && code <= 97) color = `terminal.ansiBright${names[code - 90]}`;
+			}
+		}
+		if (start < text.length) runs.push({ text: text.slice(start), bold, color });
+		return runs;
+	};
+}