std.splitLimit negative maxsplits differs from Jsonnet 0.22.0

[He-Pin]

Summary

During the stdlib 1:1 audit, std.splitLimit / std.splitLimitR were found to differ for negative maxsplits values other than -1.

Official C++ Jsonnet v0.22.0 treats negative integer maxsplits as unlimited splitting. sjsonnet currently rejects values below -1.

Evidence

Environment:

• official C++ Jsonnet: Jsonnet commandline interpreter v0.22.0
• go-jsonnet: Jsonnet commandline interpreter (Go implementation) v0.22.0
• jrsonnet: source-built jrsonnet 0.5.0-pre98, commit 80cd36abd868507312e2cc2c78cb0f55a684c620
• sjsonnet: PR fix: Align stdlib 1:1 edge semantics #800 worktree assembly

expression	official Jsonnet 0.22.0	go-jsonnet 0.22.0	source-built jrsonnet	sjsonnet PR #800
std.splitLimit("a,b,c", ",", -1)	["a","b","c"]	["a","b","c"]	["a","b","c"]	["a","b","c"]
std.splitLimit("a,b,c", ",", -2)	["a","b","c"]	error	error	error
std.splitLimit("a,b,c", ",", -0.5)	["a,b,c"]	error	error	["a,b,c"]
std.splitLimit("a,b,c", ",", 0.5)	["a,b,c"]	error	error	["a,b,c"]
std.splitLimit("a,b,c", ",", 1.5)	["a","b,c"]	error	error	["a","b,c"]
std.splitLimitR("a,b,c", ",", -2)	["a","b","c"]	error	error	error

Notes

This edge is subtle:

• official C++ Jsonnet's observed CLI behavior treats negative integer limits as unlimited;
• go-jsonnet and jrsonnet reject values below -1;
• sjsonnet currently matches go/jrsonnet for -2, but matches official for fractional values that truncate to 0 or 1.

Direction

For strict official CLI compatibility, sjsonnet should treat negative integer maxsplits values as unlimited, not only -1, while preserving the current fractional truncation behavior that already matches official for -0.5, 0.5, and 1.5.

Add direction tests for both splitLimit and splitLimitR.