sx: step 13 — buffer primitives + buffer-based inspect

Added short aliases make-buffer / buffer? / buffer-append! / buffer->string /
buffer-length on both OCaml and JS hosts, sharing the existing StringBuffer
value type. buffer-append! auto-coerces non-strings via inspect.

Rewrote the OCaml host inspect function to walk a single shared Buffer.t
instead of allocating O(n) intermediate strings via String.concat at every
recursion level. inspect underlies sx-serialize and error-path formatting,
so this benefits the tightest serialization paths.

Median improvements (bin/bench_inspect.exe, best-of-3 of 9-run min):
  tree-d8 (75KB):    5.31ms -> 1.30ms  (-76%)
  tree-d10 (679KB): 81.89ms -> 16.02ms (-80%)
  dict-1000:         0.80ms -> 0.31ms  (-61%)
  list-2000:         0.74ms -> 0.33ms  (-55%)

Tests: OCaml 4545 -> 4550. JS 2591 -> 2596. Zero regressions.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
2026-05-07 02:16:59 +00:00
parent c48911e591
commit 0e022ab670
9 changed files with 303 additions and 67 deletions

View File

@@ -41,7 +41,7 @@
// =========================================================================
var NIL = Object.freeze({ _nil: true, toString: function() { return "nil"; } });
var SX_VERSION = "2026-05-07T00:02:13Z";
var SX_VERSION = "2026-05-07T02:05:49Z";
function isNil(x) { return x === NIL || x === null || x === undefined; }
function isSxTruthy(x) { return x !== false && !isNil(x); }
@@ -911,6 +911,22 @@
PRIMITIVES["string-buffer->string"] = function(buf) { return buf.parts.join(""); };
PRIMITIVES["string-buffer-length"] = function(buf) { return buf.len; };
// Short aliases — terser names; append accepts any value
PRIMITIVES["make-buffer"] = function() { return new SxStringBuffer(); };
PRIMITIVES["buffer?"] = function(x) { return x instanceof SxStringBuffer; };
PRIMITIVES["buffer-append!"] = function(buf, v) {
var s;
if (v === null || v === undefined || v === NIL) s = "";
else if (typeof v === "string") s = v;
else if (typeof v === "boolean") s = v ? "true" : "false";
else if (typeof v === "number") s = String(v);
else if (v && typeof v === "object" && typeof v.name === "string" && v.constructor && v.constructor.name === "Symbol") s = v.name;
else s = (typeof inspect === "function") ? inspect(v) : String(v);
buf.parts.push(s); buf.len += s.length; return NIL;
};
PRIMITIVES["buffer->string"] = function(buf) { return buf.parts.join(""); };
PRIMITIVES["buffer-length"] = function(buf) { return buf.len; };
// stdlib.format
PRIMITIVES["format-decimal"] = function(v, p) { return Number(v).toFixed(p || 2); };