From 5ab8da099f84b3af47466abdd99d5dc86322b2cc Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 19:47:45 +0100
Subject: [PATCH 01/20] baseline: PR #20834 + firstNonAsciiPos (threshold 9)

---
 versions/experiment.mjs | 46 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 versions/experiment.mjs

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
new file mode 100644
index 0000000..6b70c54
--- /dev/null
+++ b/versions/experiment.mjs
@@ -0,0 +1,46 @@
+/**
+ * PR #20834 + `firstNonAsciiPos`: extends `substr` fast path into non-ASCII sources.
+ */
+
+// oxlint-disable prefer-const
+
+const textDecoder = new TextDecoder("utf-8", { ignoreBOM: true }),
+  decodeStr = textDecoder.decode.bind(textDecoder);
+
+const { fromCodePoint } = String;
+
+let firstNonAsciiPos;
+
+export function setup() {
+  // Find first non-ASCII byte in source region
+  firstNonAsciiPos = sourceEndPos;
+  for (let i = 0; i < sourceEndPos; i++) {
+    if (uint8[i] >= 128) {
+      firstNonAsciiPos = i;
+      break;
+    }
+  }
+}
+
+export function deserializeStr(pos) {
+  let pos32 = pos >> 2,
+    len = uint32[pos32 + 2];
+  if (len === 0) return "";
+  pos = uint32[pos32];
+  if (pos < sourceEndPos && (sourceIsAscii || pos + len <= firstNonAsciiPos)) {
+    return sourceText.substr(pos, len);
+  }
+  let end = pos + len;
+  if (len > 9) return decodeStr(uint8.subarray(pos, end));
+  let out = "",
+    c;
+  do {
+    c = uint8[pos++];
+    if (c < 128) out += fromCodePoint(c);
+    else {
+      out += decodeStr(uint8.subarray(pos - 1, end));
+      break;
+    }
+  } while (pos < end);
+  return out;
+}

From e1360e2134de860a49ddafa3c354bd67886d3709 Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 19:48:14 +0100
Subject: [PATCH 02/20] exp1: fromCharCode + inline textDecoder.decode

---
 versions/experiment.mjs | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index 6b70c54..f3fce86 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,18 +1,17 @@
 /**
- * PR #20834 + `firstNonAsciiPos`: extends `substr` fast path into non-ASCII sources.
+ * Experiment 1: Use String.fromCharCode instead of fromCodePoint for ASCII,
+ * and inline TextDecoder.decode to avoid bound function overhead.
  */
 
 // oxlint-disable prefer-const
 
-const textDecoder = new TextDecoder("utf-8", { ignoreBOM: true }),
-  decodeStr = textDecoder.decode.bind(textDecoder);
+const textDecoder = new TextDecoder("utf-8", { ignoreBOM: true });
 
-const { fromCodePoint } = String;
+const { fromCharCode } = String;
 
 let firstNonAsciiPos;
 
 export function setup() {
-  // Find first non-ASCII byte in source region
   firstNonAsciiPos = sourceEndPos;
   for (let i = 0; i < sourceEndPos; i++) {
     if (uint8[i] >= 128) {
@@ -31,14 +30,14 @@ export function deserializeStr(pos) {
     return sourceText.substr(pos, len);
   }
   let end = pos + len;
-  if (len > 9) return decodeStr(uint8.subarray(pos, end));
+  if (len > 9) return textDecoder.decode(uint8.subarray(pos, end));
   let out = "",
     c;
   do {
     c = uint8[pos++];
-    if (c < 128) out += fromCodePoint(c);
+    if (c < 128) out += fromCharCode(c);
     else {
-      out += decodeStr(uint8.subarray(pos - 1, end));
+      out += textDecoder.decode(uint8.subarray(pos - 1, end));
       break;
     }
   } while (pos < end);

From cfedd0b9ae29304afb5e713f17d5d493802b0377 Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 19:49:48 +0100
Subject: [PATCH 03/20] exp4: batch fromCharCode with switch on len

---
 versions/experiment.mjs | 33 +++++++++++++++++++++------------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index f3fce86..76e604f 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,6 +1,6 @@
 /**
- * Experiment 1: Use String.fromCharCode instead of fromCodePoint for ASCII,
- * and inline TextDecoder.decode to avoid bound function overhead.
+ * Experiment 4: For short ASCII strings (<=9 bytes), collect char codes
+ * and use a single fromCharCode call. Falls back to TextDecoder on non-ASCII.
  */
 
 // oxlint-disable prefer-const
@@ -31,15 +31,24 @@ export function deserializeStr(pos) {
   }
   let end = pos + len;
   if (len > 9) return textDecoder.decode(uint8.subarray(pos, end));
-  let out = "",
-    c;
-  do {
-    c = uint8[pos++];
-    if (c < 128) out += fromCharCode(c);
-    else {
-      out += textDecoder.decode(uint8.subarray(pos - 1, end));
-      break;
+  // Check if all bytes are ASCII first
+  let allAscii = true;
+  for (let i = pos; i < end; i++) {
+    if (uint8[i] >= 128) { allAscii = false; break; }
+  }
+  if (allAscii) {
+    // Single fromCharCode call with all codes
+    switch (len) {
+      case 1: return fromCharCode(uint8[pos]);
+      case 2: return fromCharCode(uint8[pos], uint8[pos+1]);
+      case 3: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2]);
+      case 4: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3]);
+      case 5: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4]);
+      case 6: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5]);
+      case 7: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6]);
+      case 8: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7]);
+      case 9: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8]);
     }
-  } while (pos < end);
-  return out;
+  }
+  return textDecoder.decode(uint8.subarray(pos, end));
 }

From 695f26936f37d1fbb0b319544bc2580ba0256cd8 Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 19:50:47 +0100
Subject: [PATCH 04/20] exp6: extend batch fromCharCode to threshold 12

---
 versions/experiment.mjs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index 76e604f..25f1208 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,6 +1,5 @@
 /**
- * Experiment 4: For short ASCII strings (<=9 bytes), collect char codes
- * and use a single fromCharCode call. Falls back to TextDecoder on non-ASCII.
+ * Experiment 6: Extend batch fromCharCode switch to threshold 12.
  */
 
 // oxlint-disable prefer-const
@@ -30,14 +29,13 @@ export function deserializeStr(pos) {
     return sourceText.substr(pos, len);
   }
   let end = pos + len;
-  if (len > 9) return textDecoder.decode(uint8.subarray(pos, end));
+  if (len > 12) return textDecoder.decode(uint8.subarray(pos, end));
   // Check if all bytes are ASCII first
   let allAscii = true;
   for (let i = pos; i < end; i++) {
     if (uint8[i] >= 128) { allAscii = false; break; }
   }
   if (allAscii) {
-    // Single fromCharCode call with all codes
     switch (len) {
       case 1: return fromCharCode(uint8[pos]);
       case 2: return fromCharCode(uint8[pos], uint8[pos+1]);
@@ -48,6 +46,9 @@ export function deserializeStr(pos) {
       case 7: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6]);
       case 8: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7]);
       case 9: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8]);
+      case 10: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9]);
+      case 11: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10]);
+      case 12: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11]);
     }
   }
   return textDecoder.decode(uint8.subarray(pos, end));

From e4b31fbd8b4689f4da98e4acb6156609b9e53fb3 Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 19:51:19 +0100
Subject: [PATCH 05/20] exp7: extend batch fromCharCode to threshold 16

---
 versions/experiment.mjs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index 25f1208..fb2f82d 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,5 +1,5 @@
 /**
- * Experiment 6: Extend batch fromCharCode switch to threshold 12.
+ * Experiment 7: Extend batch fromCharCode to threshold 16.
  */
 
 // oxlint-disable prefer-const
@@ -29,7 +29,7 @@ export function deserializeStr(pos) {
     return sourceText.substr(pos, len);
   }
   let end = pos + len;
-  if (len > 12) return textDecoder.decode(uint8.subarray(pos, end));
+  if (len > 16) return textDecoder.decode(uint8.subarray(pos, end));
   // Check if all bytes are ASCII first
   let allAscii = true;
   for (let i = pos; i < end; i++) {
@@ -49,6 +49,10 @@ export function deserializeStr(pos) {
       case 10: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9]);
       case 11: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10]);
       case 12: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11]);
+      case 13: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12]);
+      case 14: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13]);
+      case 15: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14]);
+      case 16: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15]);
     }
   }
   return textDecoder.decode(uint8.subarray(pos, end));

From 842dce4cb5145a3742477d8f7be3ee06300d2f0a Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 19:52:01 +0100
Subject: [PATCH 06/20] exp8: extend batch fromCharCode to threshold 24

---
 versions/experiment.mjs | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index fb2f82d..a4002f5 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,5 +1,5 @@
 /**
- * Experiment 7: Extend batch fromCharCode to threshold 16.
+ * Experiment 8: Extend batch fromCharCode to threshold 24.
  */
 
 // oxlint-disable prefer-const
@@ -29,7 +29,7 @@ export function deserializeStr(pos) {
     return sourceText.substr(pos, len);
   }
   let end = pos + len;
-  if (len > 16) return textDecoder.decode(uint8.subarray(pos, end));
+  if (len > 24) return textDecoder.decode(uint8.subarray(pos, end));
   // Check if all bytes are ASCII first
   let allAscii = true;
   for (let i = pos; i < end; i++) {
@@ -53,6 +53,14 @@ export function deserializeStr(pos) {
       case 14: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13]);
       case 15: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14]);
       case 16: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15]);
+      case 17: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16]);
+      case 18: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17]);
+      case 19: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18]);
+      case 20: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19]);
+      case 21: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20]);
+      case 22: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21]);
+      case 23: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22]);
+      case 24: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23]);
     }
   }
   return textDecoder.decode(uint8.subarray(pos, end));

From 3ef3cd0cebfbf927560fcb3a7d4fcca52f3510c6 Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 19:53:35 +0100
Subject: [PATCH 07/20] exp10: extend batch fromCharCode to threshold 32

---
 versions/experiment.mjs | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index a4002f5..7e16f5b 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,5 +1,5 @@
 /**
- * Experiment 8: Extend batch fromCharCode to threshold 24.
+ * Experiment 10: Extend batch fromCharCode to threshold 32.
  */
 
 // oxlint-disable prefer-const
@@ -29,7 +29,7 @@ export function deserializeStr(pos) {
     return sourceText.substr(pos, len);
   }
   let end = pos + len;
-  if (len > 24) return textDecoder.decode(uint8.subarray(pos, end));
+  if (len > 32) return textDecoder.decode(uint8.subarray(pos, end));
   // Check if all bytes are ASCII first
   let allAscii = true;
   for (let i = pos; i < end; i++) {
@@ -61,6 +61,14 @@ export function deserializeStr(pos) {
       case 22: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21]);
       case 23: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22]);
       case 24: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23]);
+      case 25: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24]);
+      case 26: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25]);
+      case 27: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26]);
+      case 28: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27]);
+      case 29: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28]);
+      case 30: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29]);
+      case 31: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30]);
+      case 32: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31]);
     }
   }
   return textDecoder.decode(uint8.subarray(pos, end));

From e08bc8dbea87a99d9752cdfd0dfe75545d6937ee Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 19:57:24 +0100
Subject: [PATCH 08/20] exp13: extend batch fromCharCode to threshold 48

---
 versions/experiment.mjs | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index 7e16f5b..58aefb7 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,5 +1,5 @@
 /**
- * Experiment 10: Extend batch fromCharCode to threshold 32.
+ * Experiment 13: Extend batch fromCharCode to threshold 48.
  */
 
 // oxlint-disable prefer-const
@@ -29,7 +29,7 @@ export function deserializeStr(pos) {
     return sourceText.substr(pos, len);
   }
   let end = pos + len;
-  if (len > 32) return textDecoder.decode(uint8.subarray(pos, end));
+  if (len > 48) return textDecoder.decode(uint8.subarray(pos, end));
   // Check if all bytes are ASCII first
   let allAscii = true;
   for (let i = pos; i < end; i++) {
@@ -69,6 +69,22 @@ export function deserializeStr(pos) {
       case 30: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29]);
       case 31: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30]);
       case 32: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31]);
+      case 33: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32]);
+      case 34: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33]);
+      case 35: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34]);
+      case 36: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35]);
+      case 37: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36]);
+      case 38: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37]);
+      case 39: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38]);
+      case 40: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39]);
+      case 41: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39], uint8[pos+40]);
+      case 42: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39], uint8[pos+40], uint8[pos+41]);
+      case 43: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39], uint8[pos+40], uint8[pos+41], uint8[pos+42]);
+      case 44: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39], uint8[pos+40], uint8[pos+41], uint8[pos+42], uint8[pos+43]);
+      case 45: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39], uint8[pos+40], uint8[pos+41], uint8[pos+42], uint8[pos+43], uint8[pos+44]);
+      case 46: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39], uint8[pos+40], uint8[pos+41], uint8[pos+42], uint8[pos+43], uint8[pos+44], uint8[pos+45]);
+      case 47: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39], uint8[pos+40], uint8[pos+41], uint8[pos+42], uint8[pos+43], uint8[pos+44], uint8[pos+45], uint8[pos+46]);
+      case 48: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39], uint8[pos+40], uint8[pos+41], uint8[pos+42], uint8[pos+43], uint8[pos+44], uint8[pos+45], uint8[pos+46], uint8[pos+47]);
     }
   }
   return textDecoder.decode(uint8.subarray(pos, end));

From 04fdac888620f30563f884837a9663ba72302974 Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 19:59:06 +0100
Subject: [PATCH 09/20] exp15: pre-decode buffer as latin1, substr for ASCII
 strings

---
 versions/experiment.mjs | 66 +++++++----------------------------------
 1 file changed, 11 insertions(+), 55 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index 58aefb7..d431aff 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,5 +1,7 @@
 /**
- * Experiment 13: Extend batch fromCharCode to threshold 48.
+ * Experiment 15: Pre-decode the entire buffer as ASCII in setup().
+ * For any ASCII string, use substr from the pre-decoded string.
+ * Only fall back to TextDecoder for non-ASCII.
  */
 
 // oxlint-disable prefer-const
@@ -9,6 +11,7 @@ const textDecoder = new TextDecoder("utf-8", { ignoreBOM: true });
 const { fromCharCode } = String;
 
 let firstNonAsciiPos;
+let bufferAsAscii;
 
 export function setup() {
   firstNonAsciiPos = sourceEndPos;
@@ -18,6 +21,11 @@ export function setup() {
       break;
     }
   }
+  // Pre-decode entire buffer as latin1 (bytes as char codes).
+  // For ASCII bytes this gives the correct string.
+  // Build using TextDecoder('latin1') which is extremely fast.
+  const latin1Decoder = new TextDecoder("latin1");
+  bufferAsAscii = latin1Decoder.decode(uint8);
 }
 
 export function deserializeStr(pos) {
@@ -29,63 +37,11 @@ export function deserializeStr(pos) {
     return sourceText.substr(pos, len);
   }
   let end = pos + len;
-  if (len > 48) return textDecoder.decode(uint8.subarray(pos, end));
-  // Check if all bytes are ASCII first
+  // Check if all bytes are ASCII
   let allAscii = true;
   for (let i = pos; i < end; i++) {
     if (uint8[i] >= 128) { allAscii = false; break; }
   }
-  if (allAscii) {
-    switch (len) {
-      case 1: return fromCharCode(uint8[pos]);
-      case 2: return fromCharCode(uint8[pos], uint8[pos+1]);
-      case 3: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2]);
-      case 4: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3]);
-      case 5: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4]);
-      case 6: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5]);
-      case 7: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6]);
-      case 8: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7]);
-      case 9: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8]);
-      case 10: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9]);
-      case 11: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10]);
-      case 12: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11]);
-      case 13: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12]);
-      case 14: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13]);
-      case 15: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14]);
-      case 16: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15]);
-      case 17: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16]);
-      case 18: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17]);
-      case 19: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18]);
-      case 20: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19]);
-      case 21: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20]);
-      case 22: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21]);
-      case 23: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22]);
-      case 24: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23]);
-      case 25: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24]);
-      case 26: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25]);
-      case 27: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26]);
-      case 28: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27]);
-      case 29: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28]);
-      case 30: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29]);
-      case 31: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30]);
-      case 32: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31]);
-      case 33: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32]);
-      case 34: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33]);
-      case 35: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34]);
-      case 36: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35]);
-      case 37: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36]);
-      case 38: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37]);
-      case 39: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38]);
-      case 40: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39]);
-      case 41: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39], uint8[pos+40]);
-      case 42: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39], uint8[pos+40], uint8[pos+41]);
-      case 43: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39], uint8[pos+40], uint8[pos+41], uint8[pos+42]);
-      case 44: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39], uint8[pos+40], uint8[pos+41], uint8[pos+42], uint8[pos+43]);
-      case 45: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39], uint8[pos+40], uint8[pos+41], uint8[pos+42], uint8[pos+43], uint8[pos+44]);
-      case 46: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39], uint8[pos+40], uint8[pos+41], uint8[pos+42], uint8[pos+43], uint8[pos+44], uint8[pos+45]);
-      case 47: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39], uint8[pos+40], uint8[pos+41], uint8[pos+42], uint8[pos+43], uint8[pos+44], uint8[pos+45], uint8[pos+46]);
-      case 48: return fromCharCode(uint8[pos], uint8[pos+1], uint8[pos+2], uint8[pos+3], uint8[pos+4], uint8[pos+5], uint8[pos+6], uint8[pos+7], uint8[pos+8], uint8[pos+9], uint8[pos+10], uint8[pos+11], uint8[pos+12], uint8[pos+13], uint8[pos+14], uint8[pos+15], uint8[pos+16], uint8[pos+17], uint8[pos+18], uint8[pos+19], uint8[pos+20], uint8[pos+21], uint8[pos+22], uint8[pos+23], uint8[pos+24], uint8[pos+25], uint8[pos+26], uint8[pos+27], uint8[pos+28], uint8[pos+29], uint8[pos+30], uint8[pos+31], uint8[pos+32], uint8[pos+33], uint8[pos+34], uint8[pos+35], uint8[pos+36], uint8[pos+37], uint8[pos+38], uint8[pos+39], uint8[pos+40], uint8[pos+41], uint8[pos+42], uint8[pos+43], uint8[pos+44], uint8[pos+45], uint8[pos+46], uint8[pos+47]);
-    }
-  }
+  if (allAscii) return bufferAsAscii.substr(pos, len);
   return textDecoder.decode(uint8.subarray(pos, end));
 }

From 5628183769058ebdcb3cbbc4c17558a58f6c1136 Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 20:01:41 +0100
Subject: [PATCH 10/20] exp19: strDataIsAscii flag + streamlined branching

---
 versions/experiment.mjs | 38 +++++++++++++++++++++++---------------
 1 file changed, 23 insertions(+), 15 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index d431aff..9017aec 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,17 +1,18 @@
 /**
- * Experiment 15: Pre-decode the entire buffer as ASCII in setup().
- * For any ASCII string, use substr from the pre-decoded string.
- * Only fall back to TextDecoder for non-ASCII.
+ * Experiment 19: Combine latin1 buffer with extended sourceText fast path.
+ * Use sourceText.substr for source strings where sourceIsAscii.
+ * Use bufferAsAscii for non-source ASCII strings (no per-byte check needed
+ * for files where all non-source content is ASCII).
+ * Fall back to per-byte check + bufferAsAscii for mixed.
  */
 
 // oxlint-disable prefer-const
 
 const textDecoder = new TextDecoder("utf-8", { ignoreBOM: true });
 
-const { fromCharCode } = String;
-
 let firstNonAsciiPos;
 let bufferAsAscii;
+let strDataIsAscii;
 
 export function setup() {
   firstNonAsciiPos = sourceEndPos;
@@ -21,11 +22,16 @@ export function setup() {
       break;
     }
   }
-  // Pre-decode entire buffer as latin1 (bytes as char codes).
-  // For ASCII bytes this gives the correct string.
-  // Build using TextDecoder('latin1') which is extremely fast.
   const latin1Decoder = new TextDecoder("latin1");
   bufferAsAscii = latin1Decoder.decode(uint8);
+  // Check if all strData bytes (after source) are ASCII
+  strDataIsAscii = true;
+  for (let i = sourceEndPos; i < uint8.length; i++) {
+    if (uint8[i] >= 128) {
+      strDataIsAscii = false;
+      break;
+    }
+  }
 }
 
 export function deserializeStr(pos) {
@@ -33,15 +39,17 @@ export function deserializeStr(pos) {
     len = uint32[pos32 + 2];
   if (len === 0) return "";
   pos = uint32[pos32];
-  if (pos < sourceEndPos && (sourceIsAscii || pos + len <= firstNonAsciiPos)) {
-    return sourceText.substr(pos, len);
+  if (pos < sourceEndPos) {
+    if (sourceIsAscii || pos + len <= firstNonAsciiPos) {
+      return sourceText.substr(pos, len);
+    }
+  } else if (strDataIsAscii) {
+    return bufferAsAscii.substr(pos, len);
   }
   let end = pos + len;
-  // Check if all bytes are ASCII
-  let allAscii = true;
+  // Per-byte ASCII check
   for (let i = pos; i < end; i++) {
-    if (uint8[i] >= 128) { allAscii = false; break; }
+    if (uint8[i] >= 128) return textDecoder.decode(uint8.subarray(pos, end));
   }
-  if (allAscii) return bufferAsAscii.substr(pos, len);
-  return textDecoder.decode(uint8.subarray(pos, end));
+  return bufferAsAscii.substr(pos, len);
 }

From ebfbf991596ed640bb8a53e35fbc601a03771c8d Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 20:06:30 +0100
Subject: [PATCH 11/20] exp24: minimize branching with firstNonAsciiBufPos

---
 versions/experiment.mjs | 49 +++++++++++++++++++----------------------
 1 file changed, 23 insertions(+), 26 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index 9017aec..55d328d 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,9 +1,7 @@
 /**
- * Experiment 19: Combine latin1 buffer with extended sourceText fast path.
- * Use sourceText.substr for source strings where sourceIsAscii.
- * Use bufferAsAscii for non-source ASCII strings (no per-byte check needed
- * for files where all non-source content is ASCII).
- * Fall back to per-byte check + bufferAsAscii for mixed.
+ * Experiment 24: Minimize branching. Use bufferAsAscii as default,
+ * only check for non-ASCII when the string might contain it.
+ * Pre-compute firstNonAsciiBufPos to cover entire buffer.
  */
 
 // oxlint-disable prefer-const
@@ -11,27 +9,25 @@
 const textDecoder = new TextDecoder("utf-8", { ignoreBOM: true });
 
 let firstNonAsciiPos;
+let firstNonAsciiBufPos; // first non-ASCII byte in entire buffer
 let bufferAsAscii;
-let strDataIsAscii;
 
 export function setup() {
   firstNonAsciiPos = sourceEndPos;
-  for (let i = 0; i < sourceEndPos; i++) {
+  firstNonAsciiBufPos = uint8.length;
+  for (let i = 0; i < uint8.length; i++) {
     if (uint8[i] >= 128) {
-      firstNonAsciiPos = i;
-      break;
+      if (i < sourceEndPos && firstNonAsciiPos === sourceEndPos) {
+        firstNonAsciiPos = i;
+      }
+      if (firstNonAsciiBufPos === uint8.length) {
+        firstNonAsciiBufPos = i;
+      }
+      if (firstNonAsciiPos < sourceEndPos) break;
     }
   }
   const latin1Decoder = new TextDecoder("latin1");
   bufferAsAscii = latin1Decoder.decode(uint8);
-  // Check if all strData bytes (after source) are ASCII
-  strDataIsAscii = true;
-  for (let i = sourceEndPos; i < uint8.length; i++) {
-    if (uint8[i] >= 128) {
-      strDataIsAscii = false;
-      break;
-    }
-  }
 }
 
 export function deserializeStr(pos) {
@@ -39,17 +35,18 @@ export function deserializeStr(pos) {
     len = uint32[pos32 + 2];
   if (len === 0) return "";
   pos = uint32[pos32];
-  if (pos < sourceEndPos) {
-    if (sourceIsAscii || pos + len <= firstNonAsciiPos) {
-      return sourceText.substr(pos, len);
-    }
-  } else if (strDataIsAscii) {
-    return bufferAsAscii.substr(pos, len);
-  }
+  // Source string in ASCII prefix: use sourceText (handles byte=char offset)
+  if (pos + len <= firstNonAsciiPos) return sourceText.substr(pos, len);
+  // String ends before any non-ASCII in buffer: use bufferAsAscii
+  if (pos + len <= firstNonAsciiBufPos) return bufferAsAscii.substr(pos, len);
+  // Need to check: might be ASCII (after non-ASCII region) or non-ASCII
   let end = pos + len;
-  // Per-byte ASCII check
   for (let i = pos; i < end; i++) {
-    if (uint8[i] >= 128) return textDecoder.decode(uint8.subarray(pos, end));
+    if (uint8[i] >= 128) {
+      // Non-ASCII: source strings use sourceText via TextDecoder, others use TextDecoder
+      return textDecoder.decode(uint8.subarray(pos, end));
+    }
   }
+  // All ASCII: use bufferAsAscii
   return bufferAsAscii.substr(pos, len);
 }

From a07cdd49ac87796e8df69c530ea81aac300cb94d Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 20:06:58 +0100
Subject: [PATCH 12/20] exp24b: fix source boundary + separate
 source/non-source paths

---
 versions/experiment.mjs | 51 ++++++++++++++++++++++-------------------
 1 file changed, 28 insertions(+), 23 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index 55d328d..95d71ac 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,7 +1,6 @@
 /**
- * Experiment 24: Minimize branching. Use bufferAsAscii as default,
- * only check for non-ASCII when the string might contain it.
- * Pre-compute firstNonAsciiBufPos to cover entire buffer.
+ * Experiment 24b: Fix source boundary handling. Source strings always
+ * go through sourceText path. Non-source strings use bufferAsAscii.
  */
 
 // oxlint-disable prefer-const
@@ -9,25 +8,26 @@
 const textDecoder = new TextDecoder("utf-8", { ignoreBOM: true });
 
 let firstNonAsciiPos;
-let firstNonAsciiBufPos; // first non-ASCII byte in entire buffer
 let bufferAsAscii;
+let strDataIsAscii;
 
 export function setup() {
   firstNonAsciiPos = sourceEndPos;
-  firstNonAsciiBufPos = uint8.length;
-  for (let i = 0; i < uint8.length; i++) {
+  for (let i = 0; i < sourceEndPos; i++) {
     if (uint8[i] >= 128) {
-      if (i < sourceEndPos && firstNonAsciiPos === sourceEndPos) {
-        firstNonAsciiPos = i;
-      }
-      if (firstNonAsciiBufPos === uint8.length) {
-        firstNonAsciiBufPos = i;
-      }
-      if (firstNonAsciiPos < sourceEndPos) break;
+      firstNonAsciiPos = i;
+      break;
     }
   }
   const latin1Decoder = new TextDecoder("latin1");
   bufferAsAscii = latin1Decoder.decode(uint8);
+  strDataIsAscii = true;
+  for (let i = sourceEndPos; i < uint8.length; i++) {
+    if (uint8[i] >= 128) {
+      strDataIsAscii = false;
+      break;
+    }
+  }
 }
 
 export function deserializeStr(pos) {
@@ -35,18 +35,23 @@ export function deserializeStr(pos) {
     len = uint32[pos32 + 2];
   if (len === 0) return "";
   pos = uint32[pos32];
-  // Source string in ASCII prefix: use sourceText (handles byte=char offset)
-  if (pos + len <= firstNonAsciiPos) return sourceText.substr(pos, len);
-  // String ends before any non-ASCII in buffer: use bufferAsAscii
-  if (pos + len <= firstNonAsciiBufPos) return bufferAsAscii.substr(pos, len);
-  // Need to check: might be ASCII (after non-ASCII region) or non-ASCII
+  // Source strings
+  if (pos < sourceEndPos) {
+    if (sourceIsAscii || pos + len <= firstNonAsciiPos) {
+      return sourceText.substr(pos, len);
+    }
+    // Source string past firstNonAsciiPos - check bytes
+    let end = pos + len;
+    for (let i = pos; i < end; i++) {
+      if (uint8[i] >= 128) return textDecoder.decode(uint8.subarray(pos, end));
+    }
+    return bufferAsAscii.substr(pos, len);
+  }
+  // Non-source strings
+  if (strDataIsAscii) return bufferAsAscii.substr(pos, len);
   let end = pos + len;
   for (let i = pos; i < end; i++) {
-    if (uint8[i] >= 128) {
-      // Non-ASCII: source strings use sourceText via TextDecoder, others use TextDecoder
-      return textDecoder.decode(uint8.subarray(pos, end));
-    }
+    if (uint8[i] >= 128) return textDecoder.decode(uint8.subarray(pos, end));
   }
-  // All ASCII: use bufferAsAscii
   return bufferAsAscii.substr(pos, len);
 }

From 69d3b2d35478b28db6551462714e8019d78ed742 Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 20:08:13 +0100
Subject: [PATCH 13/20] exp26: add lastNonAsciiSrcEnd for tail-ASCII fast path

---
 versions/experiment.mjs | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index 95d71ac..e1a66b6 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,6 +1,8 @@
 /**
- * Experiment 24b: Fix source boundary handling. Source strings always
- * go through sourceText path. Non-source strings use bufferAsAscii.
+ * Experiment 26: Add lastNonAsciiSrcEnd to extend fast path.
+ * Source strings before firstNonAsciiPos: sourceText.substr
+ * Source strings after lastNonAsciiSrcEnd: bufferAsAscii.substr (no scan)
+ * Source strings between: per-byte scan
  */
 
 // oxlint-disable prefer-const
@@ -8,15 +10,17 @@
 const textDecoder = new TextDecoder("utf-8", { ignoreBOM: true });
 
 let firstNonAsciiPos;
+let lastNonAsciiSrcEnd; // byte pos after last non-ASCII byte in source
 let bufferAsAscii;
 let strDataIsAscii;
 
 export function setup() {
   firstNonAsciiPos = sourceEndPos;
+  lastNonAsciiSrcEnd = 0;
   for (let i = 0; i < sourceEndPos; i++) {
     if (uint8[i] >= 128) {
-      firstNonAsciiPos = i;
-      break;
+      if (firstNonAsciiPos === sourceEndPos) firstNonAsciiPos = i;
+      lastNonAsciiSrcEnd = i + 1;
     }
   }
   const latin1Decoder = new TextDecoder("latin1");
@@ -40,7 +44,11 @@ export function deserializeStr(pos) {
     if (sourceIsAscii || pos + len <= firstNonAsciiPos) {
       return sourceText.substr(pos, len);
     }
-    // Source string past firstNonAsciiPos - check bytes
+    // After all non-ASCII source bytes: guaranteed ASCII
+    if (pos >= lastNonAsciiSrcEnd) {
+      return bufferAsAscii.substr(pos, len);
+    }
+    // In the non-ASCII zone: per-byte scan
     let end = pos + len;
     for (let i = pos; i < end; i++) {
       if (uint8[i] >= 128) return textDecoder.decode(uint8.subarray(pos, end));

From 86720dc6369975c036e3ef6138ed05845291dfef Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 20:09:55 +0100
Subject: [PATCH 14/20] exp29: cumulative non-ASCII count for O(1) ASCII range
 check

---
 versions/experiment.mjs | 34 +++++++++++++++++++---------------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index e1a66b6..847f7eb 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,8 +1,6 @@
 /**
- * Experiment 26: Add lastNonAsciiSrcEnd to extend fast path.
- * Source strings before firstNonAsciiPos: sourceText.substr
- * Source strings after lastNonAsciiSrcEnd: bufferAsAscii.substr (no scan)
- * Source strings between: per-byte scan
+ * Experiment 29: Pre-compute cumulative non-ASCII byte count.
+ * O(1) ASCII check for any range: nonAsciiCum[end] - nonAsciiCum[pos] === 0.
  */
 
 // oxlint-disable prefer-const
@@ -10,9 +8,10 @@
 const textDecoder = new TextDecoder("utf-8", { ignoreBOM: true });
 
 let firstNonAsciiPos;
-let lastNonAsciiSrcEnd; // byte pos after last non-ASCII byte in source
+let lastNonAsciiSrcEnd;
 let bufferAsAscii;
 let strDataIsAscii;
+let nonAsciiCum; // cumulative non-ASCII count
 
 export function setup() {
   firstNonAsciiPos = sourceEndPos;
@@ -32,6 +31,14 @@ export function setup() {
       break;
     }
   }
+  // Build cumulative non-ASCII count for entire buffer
+  nonAsciiCum = new Uint32Array(uint8.length + 1);
+  let count = 0;
+  for (let i = 0; i < uint8.length; i++) {
+    nonAsciiCum[i] = count;
+    if (uint8[i] >= 128) count++;
+  }
+  nonAsciiCum[uint8.length] = count;
 }
 
 export function deserializeStr(pos) {
@@ -39,27 +46,24 @@ export function deserializeStr(pos) {
     len = uint32[pos32 + 2];
   if (len === 0) return "";
   pos = uint32[pos32];
-  // Source strings
   if (pos < sourceEndPos) {
     if (sourceIsAscii || pos + len <= firstNonAsciiPos) {
       return sourceText.substr(pos, len);
     }
-    // After all non-ASCII source bytes: guaranteed ASCII
     if (pos >= lastNonAsciiSrcEnd) {
       return bufferAsAscii.substr(pos, len);
     }
-    // In the non-ASCII zone: per-byte scan
+    // O(1) ASCII check using cumulative count
     let end = pos + len;
-    for (let i = pos; i < end; i++) {
-      if (uint8[i] >= 128) return textDecoder.decode(uint8.subarray(pos, end));
+    if (nonAsciiCum[end] === nonAsciiCum[pos]) {
+      return bufferAsAscii.substr(pos, len);
     }
-    return bufferAsAscii.substr(pos, len);
+    return textDecoder.decode(uint8.subarray(pos, end));
   }
-  // Non-source strings
   if (strDataIsAscii) return bufferAsAscii.substr(pos, len);
   let end = pos + len;
-  for (let i = pos; i < end; i++) {
-    if (uint8[i] >= 128) return textDecoder.decode(uint8.subarray(pos, end));
+  if (nonAsciiCum[end] === nonAsciiCum[pos]) {
+    return bufferAsAscii.substr(pos, len);
   }
-  return bufferAsAscii.substr(pos, len);
+  return textDecoder.decode(uint8.subarray(pos, end));
 }

From e274000ae4e3d27bf3933d71fc4d53bbb1ec4ae7 Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 20:10:31 +0100
Subject: [PATCH 15/20] exp30: simplified - only cumulative count, no
 first/lastNonAscii

---
 versions/experiment.mjs | 47 +++++++++++------------------------------
 1 file changed, 12 insertions(+), 35 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index 847f7eb..c9514e6 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,36 +1,18 @@
 /**
- * Experiment 29: Pre-compute cumulative non-ASCII byte count.
- * O(1) ASCII check for any range: nonAsciiCum[end] - nonAsciiCum[pos] === 0.
+ * Experiment 30: Simplified - remove firstNonAsciiPos/lastNonAsciiSrcEnd.
+ * Use only cumulative count for all non-sourceIsAscii cases.
  */
 
 // oxlint-disable prefer-const
 
 const textDecoder = new TextDecoder("utf-8", { ignoreBOM: true });
 
-let firstNonAsciiPos;
-let lastNonAsciiSrcEnd;
 let bufferAsAscii;
-let strDataIsAscii;
-let nonAsciiCum; // cumulative non-ASCII count
+let nonAsciiCum;
 
 export function setup() {
-  firstNonAsciiPos = sourceEndPos;
-  lastNonAsciiSrcEnd = 0;
-  for (let i = 0; i < sourceEndPos; i++) {
-    if (uint8[i] >= 128) {
-      if (firstNonAsciiPos === sourceEndPos) firstNonAsciiPos = i;
-      lastNonAsciiSrcEnd = i + 1;
-    }
-  }
   const latin1Decoder = new TextDecoder("latin1");
   bufferAsAscii = latin1Decoder.decode(uint8);
-  strDataIsAscii = true;
-  for (let i = sourceEndPos; i < uint8.length; i++) {
-    if (uint8[i] >= 128) {
-      strDataIsAscii = false;
-      break;
-    }
-  }
   // Build cumulative non-ASCII count for entire buffer
   nonAsciiCum = new Uint32Array(uint8.length + 1);
   let count = 0;
@@ -46,24 +28,19 @@ export function deserializeStr(pos) {
     len = uint32[pos32 + 2];
   if (len === 0) return "";
   pos = uint32[pos32];
-  if (pos < sourceEndPos) {
-    if (sourceIsAscii || pos + len <= firstNonAsciiPos) {
-      return sourceText.substr(pos, len);
-    }
-    if (pos >= lastNonAsciiSrcEnd) {
-      return bufferAsAscii.substr(pos, len);
-    }
-    // O(1) ASCII check using cumulative count
-    let end = pos + len;
-    if (nonAsciiCum[end] === nonAsciiCum[pos]) {
-      return bufferAsAscii.substr(pos, len);
-    }
-    return textDecoder.decode(uint8.subarray(pos, end));
+  // Source strings with ASCII source
+  if (pos < sourceEndPos && sourceIsAscii) {
+    return sourceText.substr(pos, len);
   }
-  if (strDataIsAscii) return bufferAsAscii.substr(pos, len);
+  // O(1) ASCII check using cumulative count
   let end = pos + len;
   if (nonAsciiCum[end] === nonAsciiCum[pos]) {
     return bufferAsAscii.substr(pos, len);
   }
+  // Non-ASCII: need to check if it's a source string
+  if (pos < sourceEndPos) {
+    // Use TextDecoder for source strings (sourceText.substr won't work without byteToChar mapping)
+    return textDecoder.decode(uint8.subarray(pos, end));
+  }
   return textDecoder.decode(uint8.subarray(pos, end));
 }

From bc3c7bfebfb0fde265fc9b1d37866a2b85794da0 Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 20:11:10 +0100
Subject: [PATCH 16/20] exp31: maximum simplification - no sourceText, pure
 cumulative + bufferAsAscii

---
 versions/experiment.mjs | 16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index c9514e6..58c26e7 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,6 +1,7 @@
 /**
- * Experiment 30: Simplified - remove firstNonAsciiPos/lastNonAsciiSrcEnd.
- * Use only cumulative count for all non-sourceIsAscii cases.
+ * Experiment 31: Maximum simplification. No sourceText path at all.
+ * All ASCII strings use bufferAsAscii. All non-ASCII use TextDecoder.
+ * Only the cumulative count decides.
  */
 
 // oxlint-disable prefer-const
@@ -13,7 +14,6 @@ let nonAsciiCum;
 export function setup() {
   const latin1Decoder = new TextDecoder("latin1");
   bufferAsAscii = latin1Decoder.decode(uint8);
-  // Build cumulative non-ASCII count for entire buffer
   nonAsciiCum = new Uint32Array(uint8.length + 1);
   let count = 0;
   for (let i = 0; i < uint8.length; i++) {
@@ -28,19 +28,9 @@ export function deserializeStr(pos) {
     len = uint32[pos32 + 2];
   if (len === 0) return "";
   pos = uint32[pos32];
-  // Source strings with ASCII source
-  if (pos < sourceEndPos && sourceIsAscii) {
-    return sourceText.substr(pos, len);
-  }
-  // O(1) ASCII check using cumulative count
   let end = pos + len;
   if (nonAsciiCum[end] === nonAsciiCum[pos]) {
     return bufferAsAscii.substr(pos, len);
   }
-  // Non-ASCII: need to check if it's a source string
-  if (pos < sourceEndPos) {
-    // Use TextDecoder for source strings (sourceText.substr won't work without byteToChar mapping)
-    return textDecoder.decode(uint8.subarray(pos, end));
-  }
   return textDecoder.decode(uint8.subarray(pos, end));
 }

From b94307c65a9df9d40952783059342efdce020df0 Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 20:11:30 +0100
Subject: [PATCH 17/20] exp31b: restore sourceText path for ASCII source
 boundary strings

---
 versions/experiment.mjs | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index 58c26e7..dafe9ee 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,7 +1,6 @@
 /**
- * Experiment 31: Maximum simplification. No sourceText path at all.
- * All ASCII strings use bufferAsAscii. All non-ASCII use TextDecoder.
- * Only the cumulative count decides.
+ * Experiment 31b: Fix boundary case. Use sourceText.substr for source
+ * strings in ASCII sources. Use cumulative + bufferAsAscii for the rest.
  */
 
 // oxlint-disable prefer-const
@@ -28,9 +27,8 @@ export function deserializeStr(pos) {
     len = uint32[pos32 + 2];
   if (len === 0) return "";
   pos = uint32[pos32];
+  if (pos < sourceEndPos && sourceIsAscii) return sourceText.substr(pos, len);
   let end = pos + len;
-  if (nonAsciiCum[end] === nonAsciiCum[pos]) {
-    return bufferAsAscii.substr(pos, len);
-  }
+  if (nonAsciiCum[end] === nonAsciiCum[pos]) return bufferAsAscii.substr(pos, len);
   return textDecoder.decode(uint8.subarray(pos, end));
 }

From c668176116de3f37021cf9a9672050384809b4e8 Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Mon, 30 Mar 2026 20:12:02 +0100
Subject: [PATCH 18/20] exp32: micro-opts - remove len===0 check, inline pos
 read

---
 versions/experiment.mjs | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/versions/experiment.mjs b/versions/experiment.mjs
index dafe9ee..90fc850 100644
--- a/versions/experiment.mjs
+++ b/versions/experiment.mjs
@@ -1,6 +1,6 @@
 /**
- * Experiment 31b: Fix boundary case. Use sourceText.substr for source
- * strings in ASCII sources. Use cumulative + bufferAsAscii for the rest.
+ * Experiment 32: Micro-optimizations - remove len===0 check,
+ * use local references for hot variables.
  */
 
 // oxlint-disable prefer-const
@@ -24,11 +24,10 @@ export function setup() {
 
 export function deserializeStr(pos) {
   let pos32 = pos >> 2,
-    len = uint32[pos32 + 2];
-  if (len === 0) return "";
-  pos = uint32[pos32];
-  if (pos < sourceEndPos && sourceIsAscii) return sourceText.substr(pos, len);
-  let end = pos + len;
-  if (nonAsciiCum[end] === nonAsciiCum[pos]) return bufferAsAscii.substr(pos, len);
-  return textDecoder.decode(uint8.subarray(pos, end));
+    len = uint32[pos32 + 2],
+    p = uint32[pos32];
+  if (p < sourceEndPos && sourceIsAscii) return sourceText.substr(p, len);
+  let end = p + len;
+  if (nonAsciiCum[end] === nonAsciiCum[p]) return bufferAsAscii.substr(p, len);
+  return textDecoder.decode(uint8.subarray(p, end));
 }

From 2a109a17ca1753ca646e9a18123b2402f6e0e45e Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Wed, 1 Apr 2026 10:20:10 +0100
Subject: [PATCH 19/20] add sparse-table version: O(log k) binary search over
 non-ASCII drift table
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Scans the source region once in setup() to build a sparse translation
table mapping multi-byte UTF-8 character positions to cumulative
byte-vs-codeunit drift. deserializeStr() binary searches this table to
convert byte offsets to UTF-16 offsets, extending sourceText.substr()
to all source strings — not just those in the ASCII prefix.

Benchmarks show 25-65% improvement over current on non-ASCII files,
though the dense cumulative array approach (experiment.mjs) remains
faster due to O(1) lookups vs O(log k) binary search.
---
 versions/sparse-table.mjs | 127 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 127 insertions(+)
 create mode 100644 versions/sparse-table.mjs

diff --git a/versions/sparse-table.mjs b/versions/sparse-table.mjs
new file mode 100644
index 0000000..4e4bb11
--- /dev/null
+++ b/versions/sparse-table.mjs
@@ -0,0 +1,127 @@
+/**
+ * Sparse UTF-8/UTF-16 translation table: extends sourceText.substr() to ALL
+ * source strings, not just those in the ASCII prefix.
+ *
+ * Builds on pr20834-fnap.mjs. Instead of finding the first non-ASCII byte and
+ * giving up after it, we scan the source region once in setup() and record the
+ * cumulative byte-vs-codeunit drift at each multi-byte character. A binary
+ * search at read time converts byte offsets to UTF-16 offsets in O(log k),
+ * where k is the number of non-ASCII characters (typically tiny for source).
+ */
+
+// oxlint-disable prefer-const
+
+const textDecoder = new TextDecoder("utf-8", { ignoreBOM: true }),
+  decodeStr = textDecoder.decode.bind(textDecoder);
+
+const { fromCodePoint } = String;
+
+// Sparse table: parallel arrays for cache-friendly binary search.
+// tableOffsets[i] = byte offset just past the i-th multi-byte character.
+// tableDrifts[i]  = cumulative drift (utf8 bytes - utf16 code units) at that point.
+let tableOffsets;
+let tableDrifts;
+let tableLen;
+
+export function setup() {
+  // First pass: count multi-byte characters to size the arrays.
+  let count = 0;
+  for (let i = 0; i < sourceEndPos; ) {
+    let b = uint8[i];
+    if (b >= 0xf0) { count++; i += 4; }
+    else if (b >= 0xe0) { count++; i += 3; }
+    else if (b >= 0xc0) { count++; i += 2; }
+    else { i++; }
+  }
+
+  tableOffsets = new Uint32Array(count);
+  tableDrifts = new Uint32Array(count);
+  tableLen = count;
+
+  // Second pass: populate the table.
+  let drift = 0;
+  let idx = 0;
+  for (let i = 0; i < sourceEndPos; ) {
+    let b = uint8[i];
+    if (b >= 0xf0) {
+      // 4-byte sequence -> 2 UTF-16 code units (surrogate pair), drift += 2
+      drift += 2;
+      i += 4;
+      tableOffsets[idx] = i;
+      tableDrifts[idx] = drift;
+      idx++;
+    } else if (b >= 0xe0) {
+      // 3-byte sequence -> 1 UTF-16 code unit, drift += 2
+      drift += 2;
+      i += 3;
+      tableOffsets[idx] = i;
+      tableDrifts[idx] = drift;
+      idx++;
+    } else if (b >= 0xc0) {
+      // 2-byte sequence -> 1 UTF-16 code unit, drift += 1
+      drift += 1;
+      i += 2;
+      tableOffsets[idx] = i;
+      tableDrifts[idx] = drift;
+      idx++;
+    } else {
+      i++;
+    }
+  }
+}
+
+// Binary search: find the largest index where tableOffsets[index] <= target.
+// Returns -1 if target is before all entries (i.e. drift is 0).
+function findDrift(target) {
+  let lo = 0, hi = tableLen - 1, result = -1;
+  while (lo <= hi) {
+    let mid = (lo + hi) >>> 1;
+    if (tableOffsets[mid] <= target) {
+      result = mid;
+      lo = mid + 1;
+    } else {
+      hi = mid - 1;
+    }
+  }
+  return result;
+}
+
+// Get the cumulative drift at a byte offset.
+function driftAt(bytePos) {
+  if (tableLen === 0) return 0;
+  let idx = findDrift(bytePos);
+  return idx < 0 ? 0 : tableDrifts[idx];
+}
+
+export function deserializeStr(pos) {
+  let pos32 = pos >> 2,
+    len = uint32[pos32 + 2];
+  if (len === 0) return "";
+  pos = uint32[pos32];
+
+  if (pos < sourceEndPos) {
+    if (sourceIsAscii) return sourceText.substr(pos, len);
+
+    // Use the sparse table to convert byte offsets to UTF-16 offsets.
+    let startDrift = driftAt(pos);
+    let endDrift = driftAt(pos + len);
+    let utf16Start = pos - startDrift;
+    let utf16Len = len - (endDrift - startDrift);
+    return sourceText.substr(utf16Start, utf16Len);
+  }
+
+  // Outside source region: fall back to concat/TextDecoder (from pr20834-fnap).
+  let end = pos + len;
+  if (len > 9) return decodeStr(uint8.subarray(pos, end));
+  let out = "",
+    c;
+  do {
+    c = uint8[pos++];
+    if (c < 128) out += fromCodePoint(c);
+    else {
+      out += decodeStr(uint8.subarray(pos - 1, end));
+      break;
+    }
+  } while (pos < end);
+  return out;
+}

From 1e03e5a928368af223400085242c4a2c61097cf0 Mon Sep 17 00:00:00 2001
From: Josh Tuddenham <josh.tuddenham@letsdothis.com>
Date: Wed, 1 Apr 2026 10:49:01 +0100
Subject: [PATCH 20/20] fix: check entire string is within source region before
 using substr

A string starting in the source region but extending past sourceEndPos
would get truncated by sourceText.substr(). Changed the guard from
pos < sourceEndPos to pos + len <= sourceEndPos so boundary-spanning
strings correctly fall through to the TextDecoder path.
---
 versions/sparse-table.mjs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/versions/sparse-table.mjs b/versions/sparse-table.mjs
index 4e4bb11..ef68fdc 100644
--- a/versions/sparse-table.mjs
+++ b/versions/sparse-table.mjs
@@ -99,7 +99,7 @@ export function deserializeStr(pos) {
   if (len === 0) return "";
   pos = uint32[pos32];
 
-  if (pos < sourceEndPos) {
+  if (pos + len <= sourceEndPos) {
     if (sourceIsAscii) return sourceText.substr(pos, len);
 
     // Use the sparse table to convert byte offsets to UTF-16 offsets.