WolframExpr

Incomplete work in progress. Open an issue if you find bugs or have requests.

WolframExpr is a package for translating Wolfram Language expressions to Julia functions.

Mathematica, Wolfram, MathLink are all trademarks of Wolfram Research.

The primary function is string_to_function, which converts a string containing a Wolfram Language expression to a Julia function.

For example,

julia> using WolframExpr
julia> f = string_to_function("A[x,y]+y", [:A, :x, :y]);ERROR: MethodError: no method matching wexpr_to_expr(::String)

Closest candidates are:
  wexpr_to_expr(!Matched::MathLink.WExpr)
   @ WolframExpr /__w/WolframExpr.jl/WolframExpr.jl/src/WolframExpr.jl:102
  wexpr_to_expr(!Matched::MathLink.WSymbol)
   @ WolframExpr /__w/WolframExpr.jl/WolframExpr.jl/src/WolframExpr.jl:90
  wexpr_to_expr(!Matched::Number)
   @ WolframExpr /__w/WolframExpr.jl/WolframExpr.jl/src/WolframExpr.jl:98
julia> A(x, y) = x^2 + y^2;
julia> f(A, 1, 2)ERROR: UndefVarError: `f` not defined

For best results using expressions from Mathematica, pass your expression through FullForm to remove special syntax.

Installation

WolframExpr depends on MathLink.jl, which requires an installation of either Mathematica or the free Wolfram Engine. If those exist, the usual Julia installation methods will install WolframExpr:

] add https://github.com/musoke/WolframExpr.jl

If this fails, the problem is likely MathLink. See its documentation for installation and troubleshooting directions.

API

WolframExpr.string_to_expr — Method

string_to_expr(string)

Convert a string to a Julia Expr.

Examples

julia> using WolframExpr

julia> string_to_expr("(x+y)/2")
:((x + y) * 2 ^ -1)

WolframExpr.string_to_function — Method

string_to_function(string, symbols)

Convert a string to a Julia function with arguments in symbols.

The resulting method has signature matching symbols.

Examples

julia> using WolframExpr

julia> f = string_to_function("x+y", [:x, :y]);

julia> f(1, 2)
3

julia> f(1.2, 2)
3.2

WolframExpr.string_to_wexpr — Method

string_to_wexpr(wolfram)

Convert a string to a MathLink.WExpr.

Very shallow wrapper around MathLink's parsing.

Examples

julia> using WolframExpr

julia> string_to_wexpr("Sin[1]")
W"Sin"(1)

WolframExpr.wexpr_to_expr — Method

wexpr_to_expr(wolfram)

Convert a Wolfram expression from a MathLink.WExpr to a Julia expression.

Examples

julia> using MathLink, WolframExpr

julia> wexpr_to_expr(W`1. + 1`)
:(1.0 + 1)