use prewalk for column replacement (#28)

* use prewalk for column replacement

* add changelog and bump patch

CHANGELOG.md

@@ -1,3 +1,7 @@
+## v0.3.3
+
+- Fixed bug when column symbols were used inside braces.
+
 ## v0.3.2
 
 - Added `@proprow`, `@eachindex` and `@groupindices` special function macros, which required compat to be raised to DataFrames v1.4.

Project.toml

@@ -1,7 +1,7 @@
 name = "DataFrameMacros"
 uuid = "75880514-38bc-4a95-a458-c2aea5a3a702"
 authors = ["Julius Krumbiegel <[email protected]> and contributors"]
-version = "0.3.2"
+version = "0.3.3"
 
 [deps]
 DataFrames = "a93c6f00-e57d-5684-b7b6-d8193f3e46c0"

src/DataFrameMacros.jl

@@ -2,7 +2,7 @@ module DataFrameMacros
 
 using Base: ident_cmp
 using DataFrames: DataFrames, transform, transform!, select, select!, combine, subset, subset!, ByRow, passmissing, groupby, AsTable, DataFrame, GroupedDataFrame
-using MacroTools: @capture
+using MacroTools: @capture, prewalk, postwalk
 
 export @transform, @transform!, @select, @select!, @combine, @subset, @subset!, @groupby, @sort, @sort!, @unique
 
@@ -535,7 +535,7 @@ function make_function_expr(formula, columns)
     end
 
     newsyms = map(x -> gensym(), columns)
-    replaced_formula = postwalk(formula) do e
+    replaced_formula = prewalk(formula) do e
         # check first if this is an escaped symbol
         # and if yes return it unwrapped
         if is_escaped_symbol(e)
@@ -593,12 +593,6 @@ function is_simple_function_call(expr::Expr, columns)
     is_simple, expr.args[1]
 end
 
-# from macrotools
-walk(x, inner, outer) = outer(x)
-walk(x::Expr, inner, outer) = outer(Expr(x.head, map(inner, x.args)...))
-postwalk(f, x) = walk(x, x -> postwalk(f, x), f)
-
-
 convert_automatic_astable_formula(x) = x
 function convert_automatic_astable_formula(e::Expr)
     e_replaced, assigned_symbols, gensyms = replace_assigned_symbols(e)

test/runtests.jl

@@ -335,6 +335,7 @@ end
     @test @select(df, :d = maximum({{Not(:a)}})) == @select(df, :d = maximum([:b, :c]))
     @test @select(df, :d = @bycol sum({{r"[bc]"}})) == @select(df, :d = @bycol sum((:b, :c)))
     @test @select(df, :d = :a < maximum({{[:b, :c]}})) == @select(df, :d = :a < maximum((:b, :c)))
+    @test @select(df, :d = :a < maximum({{Not(:a)}})) == @select(df, :d = :a < maximum((:b, :c)))
 end
 
 @testset "special cased functions" begin