update examples

TODO.md

@@ -0,0 +1,3 @@
+# TODO
+
+* Define nice show methods

example/pipe.jl

@@ -36,7 +36,7 @@ function pipe(expr)
 end
 
 macro pipe(expr)
-    esc(pipe(expr))
+    pipe(expr)
 end
 
 @testset "Pipe" begin

example/slurp.jl

@@ -3,7 +3,7 @@ using ExprManipulation
 match_slurp = MExpr(:..., Capture(:var))
 match_assign = MExpr(:(=), MExpr(:tuple, Slurp(:lexprs)), Capture(:rexpr))
 
-function create_expr(lexprs, rexpr)
+function slurp(lexprs, rexpr)
     i = 1
     n = length(lexprs)
     x = gensym()
@@ -39,7 +39,7 @@ macro slurp(expr)
     if isnothing(matches)
         error("Unsupported expression $expr")
     end
-    esc(create_expr(matches[:lexprs], matches[:rexpr]))
+    esc(slurp(matches[:lexprs], matches[:rexpr]))
 end
 
 @slurp a, b..., c = [1,2,3,4,5]

example/unpack.jl

@@ -0,0 +1,45 @@
+using ExprManipulation
+using Base.Meta: show_sexpr
+
+match_assign = MExpr(:(=), Capture(:lexpr), Capture(:rexpr))
+match_tuple  = MExpr(:tuple, Slurp(x -> x isa Array{Symbol} ,:keys))
+
+function create_expr(lexpr, rexpr)  
+    @assert match_tuple == lexpr "Unsupported left hand expresion $lexpr"
+    tmp = gensym()
+    expr = Expr(:block, :($tmp = $rexpr))
+    args = [:($key = unpack($tmp, Val{$(Expr(:quote, key))}())) for key in lexpr.args ]
+    append!(expr.args, args)
+    expr
+end
+
+create_expr(lexpr::Symbol, rexpr) = :($lexpr = unpack($rexpr, Val{$(Expr(:quote, lexpr))}()))
+
+unpack(x, ::Val{k}) where {k} = getproperty(x, k)
+unpack(x::AbstractDict{Symbol}, ::Val{k}) where {k} =  x[k]
+unpack(x::AbstractDict{<:AbstractString}, ::Val{k}) where {k} = x[string(k)]
+
+function unpack(expr)
+    matches = match(match_assign, expr)
+    !isnothing(matches) ? create_expr(matches.lexpr, matches.rexpr) : error("Unsuppored expression $expr")
+end
+
+macro unpack(input_expr)
+    esc(unpack(input_expr))
+end
+
+struct Data
+    a
+    b
+    c
+    d
+    e
+    f
+end
+
+data = Data(1, 2, 3 ,4, 5, 6)
+dict = Dict(:y=>2, "z"=>3)
+
+@unpack a, b, f = data
+@unpack d = data
+@unpack y, z = dict