#6 add volume module

elm.json

@@ -22,7 +22,8 @@
         "Resistance",
         "Speed",
         "Temperature",
-        "Voltage"
+        "Voltage",
+        "Volume"
     ],
     "elm-version": "0.19.0 <= v < 0.20.0",
     "dependencies": {

src/Quantity.elm

@@ -1,9 +1,9 @@
 module Quantity exposing
     ( Quantity(..)
-    , Squared, Rate
+    , Squared, Cubed, Rate
     , zero, infinity, positiveInfinity, negativeInfinity
     , lessThan, greaterThan, compare, equalWithin, max, min, isNaN, isInfinite
-    , negate, plus, minus, product, ratio, scaleBy, divideBy, abs, clamp, squared, sqrt
+    , negate, plus, minus, product, ratio, scaleBy, divideBy, abs, clamp, squared, sqrt, cubed, cbrt
     , round, floor, ceiling, truncate, toFloatQuantity
     , sum, minimum, maximum, sort
     , per, times, at, at_, inverse
@@ -17,10 +17,10 @@ module Quantity exposing
 
 # Unit types
 
-The `Squared` and `Rate` units types allow you to build up and work with
+The `Squared`, `Cubed` and `Rate` units types allow you to build up and work with
 composite units in a fairly flexible way.
 
-@docs Squared, Rate
+@docs Squared, Cubed, Rate
 
 
 # Constants
@@ -35,7 +35,7 @@ composite units in a fairly flexible way.
 
 # Arithmetic
 
-@docs negate, plus, minus, product, ratio, scaleBy, divideBy, abs, clamp, squared, sqrt
+@docs negate, plus, minus, product, ratio, scaleBy, divideBy, abs, clamp, squared, sqrt, cubed, cbrt
 
 
 # `Int`/`Float` conversion
@@ -111,6 +111,17 @@ type Squared units
     = Squared units
 
 
+{-| Represents a units type that is the cube of some other units type; for
+example, `Meters` is one units type (the units type of a `Length`) and `Cubed
+Meters` is another (the units type of an `Volume`). This is useful because some
+functions in this module (specifically [`cubed`](Quantity#cubed),
+and [`cbrt`](Quantity#cbrt)) "know" about the
+`Cubed` type and how to work with it.
+-}
+type Cubed units
+    = Cubed units
+
+
 {-| Represents the units type of a rate or quotient such as a speed (`Rate
 Meters Seconds`) or a pressure (`Rate Newtons SquareMeters`). As with `Squared`,
 there are several functions that "know" about the `Rate` units type and how to
@@ -504,6 +515,24 @@ sqrt (Quantity value) =
     Quantity (Basics.sqrt value)
 
 
+{-| Cube a quantity with some `units`, resulting in a new quantity in
+`Cubed units.
+-}
+cubed : Quantity number units -> Quantity number (Cubed units)
+cubed (Quantity value) =
+    Quantity (value * value * value)
+
+
+{-| Take a quantity in `Cubed units` and return the cube root of that
+quantity in plain `units.
+-}
+cbrt : Quantity Float (Cubed units) -> Quantity Float units
+cbrt (Quantity value) =
+    if value >=0 then
+        Quantity (value ^ (1 /3))
+    else
+        Quantity -((-value) ^ (1 /3))
+
 
 ---------- INT/FLOAT CONVERSIONS ----------
 

src/Volume.elm

@@ -0,0 +1,130 @@
+module Volume exposing
+    ( Volume, CubicMeters
+    , cubicMeters, inCubicMeters
+    , cubicInches, inCubicInches, cubicFeet, inCubicFeet, cubicYards, inCubicYards
+    , milliliters, inMilliliters, liters, inLiters
+    --, usLiquidGallons, usDryGallons, imperialGallons
+    --, usLiquidQuarts, usDryQuarts, imperialQuarts
+    --, usLiquidPints, usDryPints, imperialPints
+    --, usFluidOunces, imperialFluidOunces
+    )
+
+{-| A `Volume` represents a volume in cubic meters, cubic feet, liters,
+US liquid gallons, imperial fluid ounces etc. It is stored as a number of cubic meters.
+
+@docs Volume, CubicMeters
+
+
+## Metric
+
+@docs cubicMeters, inCubicMeters
+@docs milliliters, inMilliliters, liters, inLiters 
+
+
+## Imperial
+
+@docs cubicInches, inCubicInches, cubicFeet, inCubicFeet, cubicYards, inCubicYards
+--@docs usLiquidGallons, usDryGallons, imperialGallons
+--@docs usLiquidQuarts, usDryQuarts, imperialQuarts
+--@docs usLiquidPints, usDryPints, imperialPints
+--@docs usFluidOunces, imperialFluidOunces
+
+-}
+
+import Length exposing (Meters)
+import Quantity exposing (Quantity(..), Cubed)
+
+
+{-| -}
+type alias CubicMeters =
+    Cubed Meters
+
+
+{-| -}
+type alias Volume =
+    Quantity Float CubicMeters
+
+
+{-| Construct a volume from a number of cubic meters.
+-}
+cubicMeters : Float -> Volume
+cubicMeters numCubicMeters =
+    Quantity numCubicMeters
+
+
+{-| Convert a volume to a number of cubic meters.
+-}
+inCubicMeters : Volume -> Float
+inCubicMeters (Quantity numCubicMeters) =
+    numCubicMeters
+
+
+{-| Construct a volume from a number of cubic inches.
+-}
+cubicInches : Float -> Volume
+cubicInches numCubicInches =
+    cubicMeters (0.0254 * 0.0254 * 0.0254 * numCubicInches)
+
+
+{-| Convert a volume to a number of cubic inches.
+-}
+inCubicInches : Volume -> Float
+inCubicInches volume =
+    inCubicMeters volume / (0.0254 * 0.0254 * 0.0254)
+
+
+{-| Construct a volume from a number of cubic feet.
+-}
+cubicFeet : Float -> Volume
+cubicFeet numCubicFeet =
+    cubicMeters (0.3048 * 0.3048 * 0.3048 * numCubicFeet)
+
+
+{-| Convert a volume to a number of cubic feet.
+-}
+inCubicFeet : Volume -> Float
+inCubicFeet volume =
+    inCubicMeters volume / (0.3048 * 0.3048 * 0.3048)
+
+
+{-| Construct a volume from a number of cubic yards.
+-}
+cubicYards : Float -> Volume
+cubicYards numCubicYards =
+    cubicMeters (0.9144 * 0.9144 * 0.9144 * numCubicYards)
+
+
+{-| Convert a volume to a number of cubic yards.
+-}
+inCubicYards : Volume -> Float
+inCubicYards volume =
+    inCubicMeters volume / (0.9144 * 0.9144 * 0.9144)
+
+
+{-| Construct a volume from a number of milliliters.
+-}
+milliliters : Float -> Volume
+milliliters numMilliliters =
+    cubicMeters (1.0e-6 * numMilliliters)
+
+
+{-| Convert a volume to a number of milliliters.
+-}
+inMilliliters : Volume -> Float
+inMilliliters volume =
+    1.0e6 * inMilliliters volume
+
+
+{-| Construct a volume from a number of liters.
+-}
+liters : Float -> Volume
+liters numLiters =
+    cubicMeters (1.0e-6 * numLiters)
+
+
+{-| Convert a volume to a number of liters.
+-}
+inLiters : Volume -> Float
+inLiters volume =
+    1.0e6 * inLiters volume
+