Hylograph.Data.Node

type NodeID = Int

Types for working with D3 simulations and graphs.

Simulation nodes now use PARAMETERIZED TYPE pattern (matching hierarchy layouts) instead of extended row pattern. This enables:

• Typeclass instances (HasDatum)
• Typed lambdas without DatumFn wrappers
• Consistent API with TreeNode, PackNode, etc.

Hierarchy layouts use pure PureScript (Hylograph.Layout.Hierarchy.*) with their own node types. Links

type Link :: Type -> Row Type -> Typetype Link id r = { source :: id, target :: id | r }

Row-polymorphic link type parameterized by ID type (source of truth in PureScript)

Links have required source/target fields with a configurable ID type. User adds extra fields via row parameter. This replaces the opaque D3Link_Unswizzled for type-safe link handling.

Example:

-- Spago uses Int IDs
type SpagoLinkRow = (linktype :: LinkType, inSim :: Boolean)
type SpagoLink = Link Int SpagoLinkRow
-- Expands to: { source :: Int, target :: Int, linktype :: LinkType, inSim :: Boolean }

-- LesMis uses String IDs
type LesMisLink = Link String (value :: Number)
-- Expands to: { source :: String, target :: String, value :: Number }

type SwizzledLink :: Row Type -> Row Type -> Typetype SwizzledLink nodeData r = { source :: SimulationNode nodeData, target :: SimulationNode nodeData | r }

Swizzled link where source/target are node object references

After swizzling, links can access node positions via link.source.x, etc. The nodeData parameter matches the SimulationNode's row parameter.

Example:

type SpagoSwizzledLink = SwizzledLink SpagoNodeRow SpagoLinkRow

type SimulationNode :: Row Type -> Typetype SimulationNode r = Record (D3_XY + D3_VxyFxy + r)

type D3_ID :: Row Type -> Row Typetype D3_ID row = (id :: NodeID | row)

Simulation Node (Row Polymorphic - matches D3's extend behavior) Simulation node that extends user data with D3 simulation fields This matches D3's behavior: it EXTENDS your objects with position/velocity fields (unlike hierarchies which EMBED your data inside wrapper objects)

Fields managed by D3 simulation:

• x, y: Position
• vx, vy: Velocity
• fx, fy: Fixed position (Nullable - Nothing means not fixed)

User data fields go directly in the row parameter r

Example:

type MyNode = SimulationNode (id :: String, group :: Int)
-- Expands to: { x :: Number, y :: Number, vx :: Number, vy :: Number,
--               fx :: Nullable Number, fy :: Nullable Number,
--               id :: String, group :: Int }

type D3_XY :: Row Type -> Row Typetype D3_XY row = (x :: Number, y :: Number | row)

type D3_VxyFxy :: Row Type -> Row Typetype D3_VxyFxy row = (fx :: Nullable Number, fy :: Nullable Number, vx :: Number, vy :: Number | row)

type D3_FocusXY :: Row Type -> Row Typetype D3_FocusXY row = (cluster :: Int, focusX :: Number, focusY :: Number | row)