unlimited dimensions

src/attribute.jl

@@ -62,5 +62,5 @@ end
 
 Base.keys(a::Attributes) = attribnames(a.ds)
 Base.getindex(a::Attributes,name) = attrib(a.ds,name)
-Base.setindex(a::Attributes,name,data) = defAttrib(a.ds,name,data)
+Base.setindex!(a::Attributes,data,name) = defAttrib(a.ds,name,data)
 Base.show(io::IO,a::Attributes) = show_attrib(io,a)

src/dataset.jl

@@ -196,7 +196,7 @@ Base.getindex(groups::Groups,name) = group(groups.ds,name)
         return Attributes(ds)
     elseif (name == :dim) && !hasfield(typeof(ds),name)
         return Dimensions(ds)
-    elseif (name == :group) && !hasfield(typeof(ds),name) && (ds <: AbstractDataset)
+    elseif (name == :group) && !hasfield(typeof(ds),name) && (ds isa AbstractDataset)
         return Groups(ds)
     else
         return getfield(ds,name)

src/dimension.jl

@@ -69,9 +69,12 @@ end
 
 Base.keys(dims::Dimensions) = dimnames(dims.ds)
 Base.getindex(dims::Dimensions,name) = dim(dims.ds,name)
-Base.setindex(dims::Dimensions,name,data) = defDim(dims.ds,name,data)
+Base.setindex!(dims::Dimensions,data,name) = defDim(dims.ds,name,data)
 Base.show(io::IO,dims::Dimensions) = show_dim(io,dims)
 
+unlimited(dims::Dimensions) = unlimited(dims.ds)
+
+
 Base.length(a::Iterable) = length(keys(a))
 
 function Base.iterate(a::Iterable, state = collect(keys(a)))

src/types.jl

@@ -48,15 +48,15 @@ Optionally a variable can have attributes:
 
 For a writable-dataset, one should also implement:
 * `defAttrib`: define a attribute
-* `Base.setindex(v,data,indices...)`: set the data in `v` at the provided indices
+* `Base.setindex!(v,data,indices...)`: set the data in `v` at the provided indices
 
 """
 abstract type AbstractVariable{T,N} <: AbstractArray{T, N}
 end
 
 """
 A collection of attributes with a Dict-like interface dispatching to
-`attribnames`, `attrib`, `defAttrib` for `keys`, `getindex` and `setindex`
+`attribnames`, `attrib`, `defAttrib` for `keys`, `getindex` and `setindex!`
 respectively.
 """
 struct Attributes{TDS<:Union{AbstractDataset,AbstractVariable}} <: AbstractDict{SymbolOrString,Any}
@@ -65,7 +65,7 @@ end
 
 """
 A collection of dimensions with a Dict-like interface dispatching to
-`dimnames`, `dim`, `defDim` for `keys`, `getindex` and `setindex`
+`dimnames`, `dim`, `defDim` for `keys`, `getindex` and `setindex!`
 respectively.
 """
 struct Dimensions{TDS<:AbstractDataset} <: AbstractDict{SymbolOrString,Any}