Hylograph.Expr.Units

data Pixels

data Em

data Rem

data Percent

data ViewportWidth

data ViewportHeight

data Unitless

class UnitExpr :: (Type -> Type) -> Constraintclass UnitExpr repr  where

Unit expressions - create values with specific units

These constructors are interpreted differently:

• Eval: px 10.0 → 10.0 (raw number for D3)
• CodeGen: px 10.0 → "(px 10.0)" (source code)
• SVG: px 10.0 → "10px" or "10" depending on context

Members

• px :: Number -> repr Pixels
• em :: Number -> repr Em
• rem :: Number -> repr Rem
• percent :: Number -> repr Percent
• vw :: Number -> repr ViewportWidth
• vh :: Number -> repr ViewportHeight
• unitless :: Number -> repr Unitless

class UnitArith :: forall k. (k -> Type) -> Constraintclass UnitArith repr  where

Unit-safe arithmetic

You can only add/subtract values with the same unit type. Scaling (multiply by unitless) preserves the unit.

Members

• addU :: forall u. repr u -> repr u -> repr u

  Add two values with the same unit

• subU :: forall u. repr u -> repr u -> repr u

  Subtract two values with the same unit

• scaleU :: forall u. repr u -> Number -> repr u

  Scale a unit value by a unitless factor