--- a/src/Grids/grid.jl	Tue Aug 22 21:53:05 2023 +0200
+++ b/src/Grids/grid.jl	Tue Aug 22 22:44:42 2023 +0200
@@ -22,6 +22,8 @@
 Base.ndims(::Grid{T,D}) where {T,D} = D
 Base.eltype(::Type{<:Grid{T}}) where T = T
 
+Base.getindex(g::Grid, I::CartesianIndex) = g[Tuple(I)...]
+
 """
     coordinate_size(g)
 
@@ -74,7 +76,7 @@
 """
     eval_on(g::Grid, f)
 
-Lazy evaluation `f` on the grid. `f` can either be on the form `f(x,y,...)`
+Lazy evaluation of `f` on the grid. `f` can either be on the form `f(x,y,...)`
 with each coordinate as an argument, or on the form `f(x̄)` taking a
 coordinate vector.
 
@@ -89,5 +91,12 @@
     end
 end
 
+"""
+    eval_on(g::Grid, f::Number)
+
+Lazy evaluation of a scalar `f` on the grid.
+"""
+eval_on(g::Grid, f::Number) = return LazyTensors.LazyConstantArray(f, size(g))
+
 _ncomponents(::Type{<:Number}) = 1
 _ncomponents(T::Type{<:SVector}) = length(T)