From 4684c6ad15ba6eb74a54f76d816573d8dd6b475d Mon Sep 17 00:00:00 2001
From: DualFroz <me@dualfroz.com>
Date: Thu, 10 Sep 2026 13:09:16 +0200
Subject: [PATCH] feat: flesh out repl

---
 src/repl.zig | 148 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 148 insertions(+)

diff --git a/src/repl.zig b/src/repl.zig
index 0f047e7..0b3a635 100644
--- a/src/repl.zig
+++ b/src/repl.zig
@@ -2052,3 +2052,151 @@ test "table window honors --limit/--offset in partition-then-order display order
     );
 }
 
+test "table window rejects an invalid spec without crashing" {
+    const allocator = std.testing.allocator;
+    var tmp = std.testing.tmpDir(.{});
+    defer tmp.cleanup();
+    var db = try openTemp(&tmp, allocator);
+    defer db.close();
+
+    var repl = Repl.init(allocator, &db);
+    defer repl.deinit();
+
+    const out = try runScript(allocator, &repl, "table window orders bogus\n");
+    defer allocator.free(out);
+    try std.testing.expectEqualStrings("error: InvalidArgument\n", out);
+}
+
+test "table window lag/lead read the adjacent row's value within order, NULL at the partition edge" {
+    const allocator = std.testing.allocator;
+    var tmp = std.testing.tmpDir(.{});
+    defer tmp.cleanup();
+    var db = try openTemp(&tmp, allocator);
+    defer db.close();
+
+    var repl = Repl.init(allocator, &db);
+    defer repl.deinit();
+
+    const out = try runScript(allocator, &repl,
+        \\table put orders i:1 day=i:1 amount=i:10
+        \\table put orders i:2 day=i:2 amount=i:20
+        \\table put orders i:3 day=i:3 amount=i:30
+        \\table window orders lag:amount,lead:amount order day
+        \\
+    );
+    defer allocator.free(out);
+    try std.testing.expectEqualStrings(
+        "OK\nOK\nOK\n" ++
+            "__pk=1\tday=1\tamount=10\tlag_amount=(none)\tlead_amount=20\n" ++
+            "__pk=2\tday=2\tamount=20\tlag_amount=10\tlead_amount=30\n" ++
+            "__pk=3\tday=3\tamount=30\tlag_amount=20\tlead_amount=(none)\n",
+        out,
+    );
+}
+
+test "table window lag with an explicit offset and a caller-supplied default instead of NULL" {
+    const allocator = std.testing.allocator;
+    var tmp = std.testing.tmpDir(.{});
+    defer tmp.cleanup();
+    var db = try openTemp(&tmp, allocator);
+    defer db.close();
+
+    var repl = Repl.init(allocator, &db);
+    defer repl.deinit();
+
+    const out = try runScript(allocator, &repl,
+        \\table put orders i:1 day=i:1 amount=i:10
+        \\table put orders i:2 day=i:2 amount=i:20
+        \\table window orders lag:amount:1:i:-1 order day
+        \\
+    );
+    defer allocator.free(out);
+    try std.testing.expectEqualStrings(
+        "OK\nOK\n" ++
+            "__pk=1\tday=1\tamount=10\tlag_amount=-1\n" ++
+            "__pk=2\tday=2\tamount=20\tlag_amount=10\n",
+        out,
+    );
+}
+
+test "table window lag/lead --range is rejected outright, like row_number" {
+    const allocator = std.testing.allocator;
+    var tmp = std.testing.tmpDir(.{});
+    defer tmp.cleanup();
+    var db = try openTemp(&tmp, allocator);
+    defer db.close();
+
+    var repl = Repl.init(allocator, &db);
+    defer repl.deinit();
+
+    const out = try runScript(allocator, &repl,
+        \\table put orders i:1 amount=i:10
+        \\table window orders lag:amount order amount --range
+        \\
+    );
+    defer allocator.free(out);
+    try std.testing.expectEqualStrings("OK\nerror: RangeNotApplicable\n", out);
+}
+
+test "table window first_value/last_value --range: last_value shares the current tie group's last member" {
+    const allocator = std.testing.allocator;
+    var tmp = std.testing.tmpDir(.{});
+    defer tmp.cleanup();
+    var db = try openTemp(&tmp, allocator);
+    defer db.close();
+
+    var repl = Repl.init(allocator, &db);
+    defer repl.deinit();
+
+    const out = try runScript(allocator, &repl,
+        \\table put orders i:1 day=i:1 amount=i:10
+        \\table put orders i:2 day=i:1 amount=i:20
+        \\table put orders i:3 day=i:2 amount=i:5
+        \\table window orders first_value:amount,last_value:amount order day --range
+        \\
+    );
+    defer allocator.free(out);
+    try std.testing.expectEqualStrings(
+        "OK\nOK\nOK\n" ++
+            "__pk=1\tday=1\tamount=10\tfirst_value_amount=10\tlast_value_amount=20\n" ++
+            "__pk=2\tday=1\tamount=20\tfirst_value_amount=10\tlast_value_amount=20\n" ++
+            "__pk=3\tday=2\tamount=5\tfirst_value_amount=10\tlast_value_amount=5\n",
+        out,
+    );
+}
+
+test "table window last_value without --range degenerates to the row's own field (ROWS default)" {
+    const allocator = std.testing.allocator;
+    var tmp = std.testing.tmpDir(.{});
+    defer tmp.cleanup();
+    var db = try openTemp(&tmp, allocator);
+    defer db.close();
+
+    var repl = Repl.init(allocator, &db);
+    defer repl.deinit();
+
+    const out = try runScript(allocator, &repl,
+        \\table put orders i:1 day=i:1 amount=i:10
+        \\table put orders i:2 day=i:2 amount=i:20
+        \\table window orders last_value:amount order day
+        \\
+    );
+    defer allocator.free(out);
+    try std.testing.expectEqualStrings(
+        "OK\nOK\n" ++
+            "__pk=1\tday=1\tamount=10\tlast_value_amount=10\n" ++
+            "__pk=2\tday=2\tamount=20\tlast_value_amount=20\n",
+        out,
+    );
+}
+
+test "table window nth_value --range: position resolved against the CUMULATIVE frame, not just the current tie group" {
+    const allocator = std.testing.allocator;
+    var tmp = std.testing.tmpDir(.{});
+    defer tmp.cleanup();
+    var db = try openTemp(&tmp, allocator);
+    defer db.close();
+
+    var repl = Repl.init(allocator, &db);
+    defer repl.deinit();
+