ExprTools
ExprTools provides tooling for working with Julia expressions during metaprogramming. This package aims to provide light-weight performant tooling without requiring additional package dependencies.
Alternatively see the MacroTools package for a more powerful set of tools.
Currently, this package provides the splitdef, signature and combinedef functions which are useful for inspecting and manipulating function definition expressions.
splitdefworks on a function definition expression and returns aDictof its parts.combinedeftakes aDictfromsplitdefand builds it into an expression.signatureworks on aMethodreturning a similarDictthat holds the parts of the expressions that would form its signature.
e.g.
julia> using ExprTools
julia> ex = :(
function Base.f(x::T, y::T) where T
x + y
end
)
:(function Base.f(x::T, y::T) where T
#= none:3 =#
x + y
end)
julia> def = splitdef(ex)
Dict{Symbol,Any} with 5 entries:
:args => Any[:(x::T), :(y::T)]
:body => quote…
:name => :(Base.f)
:head => :function
:whereparams => Any[:T]
julia> def[:name] = :g;
julia> def[:head] = :(=);
julia> def[:body] = :(x * y);
julia> g_expr = combinedef(def)
:((g(x::T, y::T) where T) = x * y)
julia> eval(g_expr)
g (generic function with 1 method)
julia> g_method = first(methods(g))
g(x::T, y::T) where T in Main
julia> signature(g_method)
Dict{Symbol,Any} with 3 entries:
:name => :g
:args => Expr[:(x::T), :(y::T)]
:whereparams => Any[:T]