MAJOR: negative rates not expressible on several paths (human per-loan bids, bid-loan/bid-loans builtins) #126

New issue

Closed

opened 2026-10-01 15:31:08 +00:00 by Winnie · 0 comments

Winnie commented

2026-10-01 15:31:08 +00:00

Owner

Found by the v0.6.0 review (issue #118). The v0.5.0 negative-rates feature is half-wired:

The human's per-loan bid path clamps to [0, cap] (main.go:908) while the "all r" path (main.go:878) and the hook-return path (main.go:320) clamp to ±cap. A human cannot bid a negative rate on an individual loan — the documented "negative rates undercut zero-bidders" move is only reachable via the bulk command.
The (bid-loan id rate) and (bid-loans rate) builtins (ai.go:202, 214) clamp to [0, cap]. Brains using the action API can never submit a negative bid, while brains returning hook lists can. Two AI code paths with different clamp contracts.

Verified: two brains bidding via (bid-loans -0.05) and (bid-loans -0.01) → every loan booked at 0 (both clamped); the same bids returned from the hook → -0.05 wins the auction. The neg_rates tests pin the ±cap behavior at the award level, so the engine is right; only these entry points are wrong.

Found by the v0.6.0 review (issue #118). The v0.5.0 negative-rates feature is half-wired: - The human's per-loan bid path clamps to [0, cap] (main.go:908) while the "all r" path (main.go:878) and the hook-return path (main.go:320) clamp to ±cap. A human cannot bid a negative rate on an individual loan — the documented "negative rates undercut zero-bidders" move is only reachable via the bulk command. - The (bid-loan id rate) and (bid-loans rate) builtins (ai.go:202, 214) clamp to [0, cap]. Brains using the action API can never submit a negative bid, while brains returning hook lists can. Two AI code paths with different clamp contracts. Verified: two brains bidding via (bid-loans -0.05) and (bid-loans -0.01) → every loan booked at 0 (both clamped); the same bids returned from the hook → -0.05 wins the auction. The neg_rates tests pin the ±cap behavior at the award level, so the engine is right; only these entry points are wrong.

Winnie referenced this issue

2026-10-01 15:31:23 +00:00

Massive code review before v0.6.0 #118

Winnie was assigned by robertismo

2026-10-01 15:39:10 +00:00

Winnie referenced this issue from a commit

2026-10-01 15:41:33 +00:00

human input paths reject NaN/Inf; deposit rate clamped; per-loan bids +-cap (Closes #120, #126 human half)

Winnie referenced this issue

2026-10-01 15:41:46 +00:00

Human input paths reject NaN/Inf; deposit rate clamped; per-loan bids ±cap (Closes #120) #129

Winnie referenced this issue from a commit