init claude-code

ink/termio/esc.ts

@@ -0,0 +1,67 @@
+/**
+ * ESC Sequence Parser
+ *
+ * Handles simple escape sequences: ESC + one or two characters
+ */
+
+import type { Action } from './types.js'
+
+/**
+ * Parse a simple ESC sequence
+ *
+ * @param chars - Characters after ESC (not including ESC itself)
+ */
+export function parseEsc(chars: string): Action | null {
+  if (chars.length === 0) return null
+
+  const first = chars[0]!
+
+  // Full reset (RIS)
+  if (first === 'c') {
+    return { type: 'reset' }
+  }
+
+  // Cursor save (DECSC)
+  if (first === '7') {
+    return { type: 'cursor', action: { type: 'save' } }
+  }
+
+  // Cursor restore (DECRC)
+  if (first === '8') {
+    return { type: 'cursor', action: { type: 'restore' } }
+  }
+
+  // Index - move cursor down (IND)
+  if (first === 'D') {
+    return {
+      type: 'cursor',
+      action: { type: 'move', direction: 'down', count: 1 },
+    }
+  }
+
+  // Reverse index - move cursor up (RI)
+  if (first === 'M') {
+    return {
+      type: 'cursor',
+      action: { type: 'move', direction: 'up', count: 1 },
+    }
+  }
+
+  // Next line (NEL)
+  if (first === 'E') {
+    return { type: 'cursor', action: { type: 'nextLine', count: 1 } }
+  }
+
+  // Horizontal tab set (HTS)
+  if (first === 'H') {
+    return null // Tab stop, not commonly needed
+  }
+
+  // Charset selection (ESC ( X, ESC ) X, etc.) - silently ignore
+  if ('()'.includes(first) && chars.length >= 2) {
+    return null
+  }
+
+  // Unknown
+  return { type: 'unknown', sequence: `\x1b${chars}` }
+}