Revert expect

Author: JoeyT1994

src/expect.jl

@@ -4,12 +4,6 @@ using ITensorMPS: ITensorMPS, expect
 
 default_expect_alg() = "bp"
 
-function ITensorMPS.expect(
-  ψ::AbstractITensorNetwork, ops; alg=default_expect_alg(), kwargs...
-)
-  return expect(Algorithm(alg), ψ, ops; kwargs...)
-end
-
 function ITensorMPS.expect(
   ψIψ::AbstractFormNetwork, op::Op; contract_kwargs=(; sequence="automatic"), kwargs...
 )
@@ -24,27 +18,6 @@ function ITensorMPS.expect(
   return numerator / denominator
 end
 
-function ITensorMPS.expect(
-  ψIψ::AbstractFormNetwork,
-  ops::Scaled{ComplexF64,Prod{Op}};
-  contract_kwargs=(; sequence="automatic"),
-  kwargs...,
-)
-  scalar = first(ops.args)
-  iszero(scalar) && return 0.0
-  n_ops = length(ops)
-  vs = site.(ops[1:n_ops])
-  op_strings = which_op.(ops[1:n_ops])
-  ψIψ_vs = [ψIψ[operator_vertex(ψIψ, v)] for v in vs]
-  sinds = [commonind(ψIψ[ket_vertex(ψIψ, v)], ψIψ_vs[i]) for (i, v) in enumerate(vs)]
-  operators = [ITensors.op(op_strings[i], sinds[i]) for i in 1:n_ops]
-  ∂ψIψ_∂v = environment(ψIψ, operator_vertices(ψIψ, vs); kwargs...)
-  numerator = contract(vcat(∂ψIψ_∂v, operators); contract_kwargs...)[]
-  denominator = contract(vcat(∂ψIψ_∂v, ψIψ_vs); contract_kwargs...)[]
-
-  return scalar * numerator / denominator
-end
-
 function ITensorMPS.expect(
   alg::Algorithm,
   ψ::AbstractITensorNetwork,