operator support in aes function

src/aes.jl

@@ -5,8 +5,7 @@ function aes(args...; kwargs...)
 
     for arg in args
         if arg isa Pair
-            push!(col_transforms, arg)
-            push!(aes_args, arg[1])
+            @error "Calculated columns currently do not support positional aes specification."
         else
             push!(aes_args, Symbol(arg))
         end
@@ -16,8 +15,13 @@ function aes(args...; kwargs...)
 
     for (k, v) in d
         if v isa Pair
-            push!(col_transforms, v)
-            push!(aes_kwargs, String(k) => Symbol(v[1]))
+            replace_v = Symbol[]
+            for (source_index, source_colname) in enumerate(v[1])
+                push!(aes_kwargs, String(k) * string(source_index) => Symbol(source_colname))
+                push!(replace_v, Symbol(String(k) * string(source_index)))
+            end
+            push!(col_transforms, Symbol(k) => replace_v => v[2])
+            push!(aes_kwargs, String(k) => :Calculated)
         else
             push!(aes_kwargs, String(k) => Symbol(v))
         end

src/draw.jl

@@ -80,7 +80,7 @@ function Makie.SpecApi.Axis(plot::GGPlot)
                 axis_options[plottable_data[aes].label_target] = plottable_data[aes].label_function(plottable_data[aes].raw)
             end
 
-            # add the transformed data to list to eventually be passed to the plots kwargs
+            # add the transformed data to list to eventually be passed to the plot args/kwargs
             merge!(given_aes, plottable_data)
         end
 

src/extract_aes.jl

@@ -2,7 +2,7 @@ function make_aes_extractor(required_aes)
     return function extract_aes(args, kwargs)
         aes_dict = Dict{String, Symbol}() 
         args_dict = Dict{String, Any}() 
-        transforms = nothing
+        transforms = Dict{Symbol, Pair{Vector{Symbol}, AesTransform}}()
 
         for arg in args
             if arg isa DataFrame
@@ -21,18 +21,11 @@ function make_aes_extractor(required_aes)
                         push!(aes_dict, required_aes[i] => pos_arg)
                     end
                 end  
-                aes_dict = merge(aes_dict, arg.named)
-                transforms = arg.column_transformations
+                merge!(aes_dict, arg.named)
+                merge!(transforms, arg.column_transformations)
             end
         end
 
-        if !isnothing(transforms)
-            rev_aes_dict = Dict([v => k for (k, v) in aes_dict])
-            transforms = Dict([Symbol(rev_aes_dict[k]) => [Symbol(rev_aes_dict[k])] => v for (k, v) in transforms])
-        else
-            transforms = Dict{Symbol, Pair{Vector{Symbol}, AesTransform}}()
-        end
-
         d = Dict(kwargs)
         args_dict = merge(args_dict, Dict([String(key) => d[key] for key in keys(d)]))
 

src/transforms.jl

@@ -28,8 +28,8 @@ end
 # When called with a string or symbol, as would happen in an aes() call
 # returns a dict of the same type used in column_transformations
 
-(at::AesTransform)(sym::Symbol) = sym         => at
-(at::AesTransform)(str::String) = Symbol(str) => at
+(at::AesTransform)(sym::Symbol) = [sym]         => at
+(at::AesTransform)(str::String) = [Symbol(str)] => at
 
 # simplest one is as_is, which just gets a column 
 # exactly as it is in the DataFrame
@@ -169,6 +169,46 @@ import Base.:>>
 
 Base.:>>(sym::Symbol, fn::Function) = aesthetics_function(fn)(sym)
 
+# 'rithm'tic (dubious implementation)
+
+import Base.:+
+
+function add_cols_fn(target::Symbol, source::Vector{Symbol}, data::DataFrame)
+    result = data[!, source[1]] .+ data[!, source[2]]
+    return Dict{Symbol, PlottableData}(
+        target => PlottableData(
+            result,        
+            identity,                
+            nothing,            
+            nothing                   
+        )
+    )
+end
+
+function make_add_const_function(constant::Real)
+    return function add_const_fn(target::Symbol, source::Vector{Symbol}, data::DataFrame)
+        result = data[!, source[1]] .+ constant
+        return Dict{Symbol, PlottableData}(
+            target => PlottableData(
+                result,        # get the column out of the dataframe
+                identity,      # apply generic_fn to it
+                nothing,            
+                nothing                   
+            )
+        )
+    end
+end
+
+Base.:+(s1::Symbol, s2::Symbol) = [s1, s2] => AesTransform(add_cols_fn)
+Base.:+(s1::Symbol, s2::Real) = s1 => AesTransform(make_add_const_function(s2))
+Base.:+(s2::Real, s1::Symbol) = s1 => AesTransform(make_add_const_function(s2))
+#import Base.:-
+#import Base.:/
+#import Base.:*
+
+
+
+
 # tweaks
 # takes an existing PlottableData object and modifies the makie_function