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by reikonomusha 784 days ago
No need for .ein source files. We just need a programming language that allows the definition of embedded DSLs without shoving them into one-line strings. A language like Common Lisp.

Here's einsum in 200 lines of Common Lisp. All einsum expressions are statically analyzed, checked for errors, and AOT compiled to machine code: https://github.com/quil-lang/magicl/blob/master/src/high-lev...
1 comments
mcabbott 784 days ago
This is also how it works in Julia, where macros digest notation for einsum-like operations before compile-time. In fact the linked file's explanatory comment:

     (einsum (A i j) (B i k) (C k j)) 
    results in the the updates
      A[i,j] = \\sum_k B[i,k]C[k,j],
    which is equivalent to matrix multiplication.
very nearly contains the syntax used by all the Julia packages (where @ marks a macro), which is

    @tensor A[i,j] = B[i,k] * C[k,j]
(using https://github.com/Jutho/TensorOperations.jl, but see also OMEinsum, Finch, and my Tullio, TensorCast.)
link