gno.land/p/moul/x/daily/sparkline/v0

Sparklines: a numeric series as one line of block characters — Ints, Scaled, Level, Bounds, Levels, Steps.

1import "gno.land/p/moul/x/daily/sparkline/v0"
2
3sparkline.Ints([]int{3, 5, 9, 14, 12, 18, 25, 21, 16, 11, 7, 4})
4// ▁▁▂▄▃▅█▆▅▃▂▁   scaled between the series' own min and max
5
6sparkline.Scaled(pct, 0, 100)   // fixed window; outliers clamp to the ends

A realm's Render returns markdown, so a trend normally means an image, a chart library, or client-side code — none of which a realm has. Eight block runes and one line of text do the job, and gnoweb needs nothing to display them.

Everything is integer math, deliberately. Render output has to be byte-identical on every validating node, and floating point is the usual way that quietly stops being true. Scaling is integer division with floor rounding.

Three behaviours worth knowing before you use it:

• A flat series renders mid-ramp (▅▅▅▅), not along the floor. A series sitting unchanged at 1000 has no shape, but drawing it at the bottom would claim it was zero — a different thing, and a wrong one.
• Scaled clamps instead of failing. A window is chosen for readability (0..100 for a percentage), and one outlier should not be able to flatten the rest of the picture or break the Render that drew it.
• Rounding is floor, so only a value at the maximum itself reaches █. The peak of a series is always visually distinct.

Level is total: every input maps into [0, Steps), including the extremes where the scaling arithmetic would otherwise wrap. That matters because Scaled indexes the ramp with it — an out-of-range result would panic the calling realm, so it is tested against minInt/maxInt windows directly.

Rendering is O(len(values)). A realm should slice its series to a window rather than sparking an unbounded, user-grown slice.

Live demo: r/moul/x/daily/sparklinedemo · render it at /r/moul/x/daily/sparklinedemo/v0.

Part of moul/gno-contracts — moul's versioned gno.land contracts. See the repository for the full catalog, build/test tooling, and usage.

🧪 Highly experimental — potentially vibe-coded. Not audited; may break, change, or be removed at any time. Do not use with anything of value. Full disclaimer: DISCLAIMER.