Merge pull request #255 from ReactiveBayes/240-error-when-running-inf…

…er-due-to-splatting

Implement splatting variables

docs/src/developers_guide.md

@@ -122,6 +122,7 @@ GraphPPL.NodeData
 GraphPPL.NodeLabel
 GraphPPL.EdgeLabel
 GraphPPL.ProxyLabel
+GraphPPL.Splat
 GraphPPL.indexed_last
 GraphPPL.lift_index
 GraphPPL.datalabel

src/graph_engine.jl

@@ -286,6 +286,15 @@ Base.show(io::IO, label::EdgeLabel) = print(io, to_symbol(label))
 Base.:(==)(label1::EdgeLabel, label2::EdgeLabel) = label1.name == label2.name && label1.index == label2.index
 Base.hash(label::EdgeLabel, h::UInt) = hash(label.name, hash(label.index, h))
 
+"""
+    Splat{T}
+
+A type used to represent splatting in the model macro. Any call on the right hand side of ~ that uses splatting will be wrapped in this type.
+"""
+struct Splat{T}
+    collection::T
+end
+
 """
     ProxyLabel(name, index, proxied)
 
@@ -306,6 +315,9 @@ is_proxied(::Type{T}) where {T <: NodeLabel} = True()
 is_proxied(::Type{T}) where {T <: ProxyLabel} = True()
 is_proxied(::Type{T}) where {T <: AbstractArray} = is_proxied(eltype(T))
 
+proxylabel(name::Symbol, proxied::Splat{T}, index, maycreate) where {T} =
+    [proxylabel(name, proxiedelement, index, maycreate) for proxiedelement in proxied.collection]
+
 # By default, `proxylabel` set `maycreate` to `False`
 proxylabel(name::Symbol, proxied, index) = proxylabel(name, proxied, index, False())
 proxylabel(name::Symbol, proxied, index, maycreate) = proxylabel(is_proxied(proxied), name, proxied, index, maycreate)
@@ -1115,6 +1127,28 @@ __check_external_collection_compatibility(label::VariableRef, collection::Number
 # For all other we simply don't know so we assume we are compatible
 __check_external_collection_compatibility(label::VariableRef, collection, indices::Tuple) = true
 
+function Base.iterate(ref::VariableRef, state)
+    if !isnothing(external_collection(ref))
+        return iterate(external_collection(ref), state)
+    elseif !isnothing(internal_collection(ref))
+        return iterate(internal_collection(ref), state)
+    elseif haskey(ref.context, ref.name)
+        return iterate(ref.context[ref.name], state)
+    end
+    error("Cannot iterate over $(ref.name). The underlying collection for `$(ref.name)` has undefined shape.")
+end
+
+function Base.iterate(ref::VariableRef)
+    if !isnothing(external_collection(ref))
+        return iterate(external_collection(ref))
+    elseif !isnothing(internal_collection(ref))
+        return iterate(internal_collection(ref))
+    elseif haskey(ref.context, ref.name)
+        return iterate(ref.context[ref.name])
+    end
+    error("Cannot iterate over $(ref.name). The underlying collection for `$(ref.name)` has undefined shape.")
+end
+
 function Base.broadcastable(ref::VariableRef)
     if !isnothing(external_collection(ref))
         # If we have an underlying collection (e.g. data), we should instantiate all variables at the point of broadcasting 
@@ -2132,7 +2166,9 @@ Calls a plugin specific logic after the model has been created. By default does
 """
 postprocess_plugin(plugin, model) = nothing
 
-function preprocess_plugins(type::AbstractPluginTraitType, model::Model, context::Context, label::NodeLabel, nodedata::NodeData, options)::Tuple{NodeLabel, NodeData}
+function preprocess_plugins(
+    type::AbstractPluginTraitType, model::Model, context::Context, label::NodeLabel, nodedata::NodeData, options
+)::Tuple{NodeLabel, NodeData}
     plugins = filter(type, getplugins(model))
     return foldl(plugins; init = (label, nodedata)) do (label, nodedata), plugin
         return preprocess_plugin(plugin, model, context, label, nodedata, options)::Tuple{NodeLabel, NodeData}

src/model_macro.jl

@@ -472,6 +472,8 @@ function proxy_args_rhs(rhs)
         return :(GraphPPL.proxylabel($(QuoteNode(rlabel)), $rlabel, $(Expr(:tuple, index...)), GraphPPL.False()))
     elseif @capture(rhs, new(rlabel_[index__]))
         return :(GraphPPL.proxylabel($(QuoteNode(rlabel)), $rlabel, $(Expr(:tuple, index...)), GraphPPL.True()))
+    elseif @capture(rhs, rlabel_...)
+        return :(GraphPPL.proxylabel($(QuoteNode(rlabel)), GraphPPL.Splat($rlabel), nothing, GraphPPL.False())...)
     end
     return :(GraphPPL.proxylabel(:anonymous, $rhs, nothing, GraphPPL.False()))
 end