Parse javascript-like object literals in Julia into a Julia object
This package provides a macro @js that parses a Julia expression interpreted as javascript, and tries to form a Julia object from that. You can use javascript shortcuts like @js { a: b } to write Dict("a" => b) and even @js { a } to write Dict("a" => a).
I am not sure if this is useful for anything else than for me trying to understand macros and evaluation in Julia...
Parses the Julia expression as a javascript object iteral. It can be called either as @js expression or @js(expression), the latter case explicitly delimits the extent of the expression being parsed by the macro.
## input
e = 5.0
g = "gee!"
@js {
a: 1,
b: [2, 3 * 3, √],
c : {
d: "doubly-quoted string",
e
},
f.g: g
}
## results
Dict{String,Any} with 4 entries:
"f" => Dict{String,Any}("g"=>"gee!")
"c" => Dict{String,Any}("e"=>5.0,"d"=>"doubly-quoted string")
"b" => Any[2, 9, sqrt]
"a" => 1All dicts created in the process are always of type Dict{String,Any}, and all arrays are of type Array{Any}, to cater for future assignments of the elements to different types.
Please note that we can't fully parse all javascript object literals, as Julia can't interpret singly-quoted strings as strings, only single characters can be parsed like this.
@js(dotted expression) traverses a hierachical json-like object directly.
a = @js { b: { c: { d: 4 } } }
@js(a.b.c.d) == 4
@js(a.b.c) == Dict("d" => 4)
@js(a.b) == @js { c: { d: 4 } }
@js(a.b) == @js { c.d: 4 }The RHS in the last expression shows object creation in deep traversal. Standard javascript does not allow this.
You can mix strings as keys with indices.
d = @js { a: 1, b: [1, {c: 2}, 3], d: 4}
@js d.b[2].cYou make assignments in the @js expression:
@js a = { b: 3 }
@js a.b = 4
@js a.b = { c: 5 }
@js a.b.c = 6
@js a, b = [ { c: 3}, { d: 4} ]
@js dict = { d: π, e: [ 1, { f: 2}, 3], c: sin }
@js { c, d, e } = dict
c == sin ## true
d == π ## true
e == [ 1, Dict("f" => 2), 3] ## true