purescript-hylograph-selection

This is the core package of Hylograph, a PureScript library system for building interactive data visualizations. Hylograph provides declarative tree construction, force simulation, graph data structures, layout algorithms, and more — all in pure PureScript with zero JavaScript visualization dependencies. See hylograph.net for documentation, guides, and examples.

Declarative DOM tree construction and interpretation for PureScript. Zero runtime dependencies on D3 or any other JavaScript visualization library.

Interactive Demo: The Hylographic Fold — a seven-chapter guide explaining how HATS works, built entirely with HATS.

Installation

spago install hylograph-selection

Overview

Build visualizations as declarative trees using HATS (Hylomorphic Abstract Tree Syntax). A HATS tree describes what to build; interpreters decide how.

import Hylograph.HATS (elem, forEach, staticStr)
import Hylograph.HATS.Friendly as F
import Hylograph.HATS.InterpreterTick (rerender)
import Hylograph.Internal.Element.Types (ElementType(..))

barChart :: Array { label :: String, value :: Number } -> Tree
barChart data =
  elem SVG [ F.viewBox 0.0 0.0 400.0 300.0 ]
    [ forEach "bars" Group data _.label \d ->
        elem Rect
          [ F.x (d.idx * 50.0)
          , F.y (300.0 - d.value)
          , F.width 40.0
          , F.height d.value
          , F.fill "#C9A962"
          ] []
    ]

The same tree can be interpreted as SVG (rendered to the DOM), English (plain text description), Mermaid (diagram syntax), or MetaHATS (a visualization of the tree’s own structure).

Key Features

Pure PureScript scales — linear, log, pow, sqrt with D3-compatible tick/nice algorithms. 37 color interpolators (Viridis, Blues, RdYlGn, etc.). No D3 dependency.
Coordinated highlighting — hover an element and related elements across multiple views respond. Configurable identity/classify functions.
Multiple interpreters — SVG, English, Mermaid, MetaHATS, SemiQuine (code generation).
Composable trees — combine fragments with siblings, nest with forEach.

Modules

Core

Hylograph.HATS — Tree types, elem, forEach, withBehaviors
Hylograph.HATS.Friendly — Attribute helpers (F.width, F.cx, F.fill, etc.)
Hylograph.HATS.InterpreterTick — DOM rendering (rerender)

Scales (pure, no D3)

Hylograph.Scale — Facade re-exporting Pure + ColorSchemes + Interpolation
Hylograph.Scale.Pure — Linear, log, pow, sqrt scales with tick/nice
Hylograph.Scale.ColorSchemes — Categorical palettes (Category10, Tableau10, etc.)
Hylograph.Scale.Sequential — 37 sequential/diverging/cyclical color interpolators
Hylograph.Scale.Interpolation — RGB and HSL color interpolation
Hylograph.Scale.FP — Sampling, modifiers, quantize, threshold

Interpreters

Hylograph.Interpreter.English — Plain English description
Hylograph.Interpreter.Mermaid — Mermaid diagram generation
Hylograph.Interpreter.SemiQuine — PureScript code generation
Hylograph.Interpreter.MetaHATS — Tree structure visualization

Interactions

Hylograph.Interaction.Coordinated — Coordinated highlighting across views
Hylograph.Interaction.Zoom — Zoom and pan
Hylograph.Interaction.Brush — Brush selection
Hylograph.Interaction.Pointer — Pointer events

The Hylograph Library System

This package is the foundation. The full ecosystem:

Package	Description
hylograph-selection	Core: HATS tree construction, interpreters (SVG, English, Mermaid, MetaHATS), scales, color schemes, coordinated highlighting, zoom, brush, pointer events. This package.
hylograph-graph	Graph data structures — adjacency lists, traversals, connected components, topological sort.
hylograph-layout	Layout algorithms — tree layouts, edge bundling, Sankey diagrams, treemaps, beeswarm, force-directed placement.
hylograph-simulation	Force simulation — n-body, collision, link forces, centering. Halogen integration for animated simulations.
hylograph-simulation-halogen	Halogen component wrapper for force simulations with tick-driven rendering.
hylograph-canvas	Canvas rendering backend for high-performance visualizations.
hylograph-optics	Optics (lenses, prisms) for traversing and transforming HATS trees.
hylograph-music	Proof of concept: interpret data to sound just as readily as data to visuals. Same fold, different output.

All packages are published to the PureScript Registry and documented at hylograph.net.

License

MIT