From b0cbdaf713c47680c55c908e25ee08ae33ab6566 Mon Sep 17 00:00:00 2001
From: giles <giles.bradshaw@rose-ash.com>
Date: Sat, 9 May 2026 09:24:41 +0000
Subject: [PATCH] ocaml: phase 5.1 pretty_table.ml baseline (Buffer + Printf
 widths, len = 64)

Builds a 4-row scoreboard via Buffer + Printf.sprintf:

  Buffer.add_string buf (Printf.sprintf '%-10s %4d\n' name score)

Each row is exactly 16 chars regardless of actual name/score length:
  10 name padding + 1 space + 4 score padding + 1 newline.
4 rows -> 64 chars total.

Combines:
  - Buffer.add_string + Printf.sprintf
  - %-Ns left-justified string and %Nd right-justified int width
  - List.iter on tuple-pattern args (iter 101 fun (a, b))

42 baseline programs total.
---
 lib/ocaml/baseline/expected.json   |  1 +
 lib/ocaml/baseline/pretty_table.ml | 10 ++++++++++
 plans/ocaml-on-sx.md               |  8 ++++++++
 3 files changed, 19 insertions(+)
 create mode 100644 lib/ocaml/baseline/pretty_table.ml

diff --git a/lib/ocaml/baseline/expected.json b/lib/ocaml/baseline/expected.json
index ee54648f..ae92cffc 100644
--- a/lib/ocaml/baseline/expected.json
+++ b/lib/ocaml/baseline/expected.json
@@ -29,6 +29,7 @@
   "mutable_record.ml": 10,
   "option_match.ml": 5,
   "pi_leibniz.ml": 314,
+  "pretty_table.ml": 64,
   "poly_stack.ml": 5,
   "queens.ml": 2,
   "quicksort.ml": 44,
diff --git a/lib/ocaml/baseline/pretty_table.ml b/lib/ocaml/baseline/pretty_table.ml
new file mode 100644
index 00000000..a3df8e3c
--- /dev/null
+++ b/lib/ocaml/baseline/pretty_table.ml
@@ -0,0 +1,10 @@
+let table rows =
+  let buf = Buffer.create 64 in
+  List.iter (fun (name, score) ->
+    Buffer.add_string buf (Printf.sprintf "%-10s %4d\n" name score)
+  ) rows;
+  Buffer.contents buf
+
+;;
+
+String.length (table [("alice", 95); ("bob", 67); ("carol", 100); ("dave", 8)])
diff --git a/plans/ocaml-on-sx.md b/plans/ocaml-on-sx.md
index b767af7c..f4747065 100644
--- a/plans/ocaml-on-sx.md
+++ b/plans/ocaml-on-sx.md
@@ -407,6 +407,14 @@ _Newest first._
   binary search tree (`type 'a tree = Leaf | Node of 'a * 'a tree *
   'a tree`) with insert + in-order traversal. Tests parametric ADT,
   recursive match, List.append, List.fold_left.
+- 2026-05-09 Phase 5.1 — pretty_table.ml baseline (Buffer + Printf
+  width specifiers, total length 64). Builds a 4-row scoreboard via
+  Buffer + `Printf.sprintf "%-10s %4d\n"`. Each row is exactly 16
+  chars (10 name + 1 space + 4 score + 1 newline) regardless of
+  actual content length thanks to width padding. 4 rows = 64 chars.
+  Combines Buffer.add_string + Printf.sprintf with `%-Ns` /
+  `%Nd` width specifiers + List.iter on tuple-pattern args. 42
+  baseline programs total.
 - 2026-05-09 Phase 4 — bitwise ops `land`/`lor`/`lxor`/`lsl`/`lsr`/
   `asr` + bits.ml baseline (popcount-sum = 21) (+5 tests, 607 total).
   The binop precedence table already had these but eval-op fell