[ITensors] Remove usage of get on keyword arguments (#1241)

Author: mtfishman

src/ITensorChainRules/mps/mpo.jl

@@ -34,14 +34,12 @@ function rrule(::typeof(-), x1::MPO, x2::MPO; kwargs...)
   return rrule(+, x1, -x2; kwargs...)
 end
 
-function rrule(::typeof(tr), x::MPO; kwargs...)
-  y = tr(x; kwargs...)
+function rrule(::typeof(tr), x::MPO; plev=(0 => 1), kwargs...)
+  y = tr(x; plev, kwargs...)
   function tr_pullback(ȳ)
     s = noprime(firstsiteinds(x))
     n = length(s)
     x̄ = MPO(s, "Id")
-
-    plev = get(kwargs, :plev, 0 => 1)
     for j in 1:n
       x̄[j] = mapprime(x̄[j], 0 => first(plev), 1 => last(plev))
     end

src/index.jl

@@ -35,7 +35,7 @@ struct Index{T}
   dir::Arrow
   tags::TagSet
   plev::Int
-  function Index{T}(id, space::T, dir, tags, plev) where {T}
+  function Index{T}(id, space::T, dir::Arrow, tags, plev) where {T}
     return new{T}(id, space, dir, tags, plev)
   end
 end
@@ -48,6 +48,11 @@ end
 # mostly for internal usage
 Index{T}(dim::T) where {T} = Index(dim)
 
+# `Nothing` direction gets converted to `Neither`.
+function Index{T}(id, space::T, dir::Nothing, tags, plev) where {T}
+  return Index{T}(id, space, Neither, tags, plev)
+end
+
 function Index(id, space::T, dir, tags, plev) where {T}
   return Index{T}(id, space, dir, tags, plev)
 end
@@ -101,7 +106,7 @@ julia> tags(i)
 ```
 """
 function Index(dim::Number, tags::Union{AbstractString,TagSet}; plev::Int=0)
-  return Index(dim; tags=tags, plev=plev)
+  return Index(dim; tags, plev)
 end
 
 # This is so that when IndexSets are converted
@@ -657,8 +662,7 @@ function Base.show(io::IO, i::Index)
   end
 end
 
-function readcpp(io::IO, ::Type{Index}; kwargs...)
-  format = get(kwargs, :format, "v3")
+function readcpp(io::IO, ::Type{Index}; format="v3")
   if format != "v3"
     throw(ArgumentError("read Index: format=$format not supported"))
   end

src/indexset.jl

@@ -910,13 +910,12 @@ block(inds::Indices, vals::Integer...) = blockindex(inds, vals...)[2]
 # Read and write
 #
 
-function readcpp(io::IO, ::Type{<:Indices}; kwargs...)
-  format = get(kwargs, :format, "v3")
+function readcpp(io::IO, ::Type{<:Indices}; format="v3")
   is = IndexSet()
   if format == "v3"
     size = read(io, Int)
     function readind(io, n)
-      i = readcpp(io, Index; kwargs...)
+      i = readcpp(io, Index; format)
       stride = read(io, UInt64)
       return i
     end

src/itensor.jl

@@ -2073,8 +2073,7 @@ function show(io::IO, mime::MIME"text/plain", T::ITensor)
   return summary(io, T)
 end
 
-function readcpp(io::IO, ::Type{Dense{ValT}}; kwargs...) where {ValT}
-  format = get(kwargs, :format, "v3")
+function readcpp(io::IO, ::Type{Dense{ValT}}; format="v3") where {ValT}
   if format == "v3"
     size = read(io, UInt64)
     data = Vector{ValT}(undef, size)
@@ -2087,8 +2086,7 @@ function readcpp(io::IO, ::Type{Dense{ValT}}; kwargs...) where {ValT}
   end
 end
 
-function readcpp(io::IO, ::Type{ITensor}; kwargs...)
-  format = get(kwargs, :format, "v3")
+function readcpp(io::IO, ::Type{ITensor}; format="v3")
   if format == "v3"
     # TODO: use Vector{Index} here?
     inds = readcpp(io, IndexSet; kwargs...)

src/iterativesolvers.jl

@@ -43,7 +43,9 @@ function expand_krylov_space(M::Matrix{elT}, V, AV, ni) where {elT}
   return newM
 end
 
-function davidson(A, phi0::ITensorT; kwargs...) where {ITensorT<:ITensor}
+function davidson(
+  A, phi0::ITensorT; maxiter=2, miniter=1, errgoal=1e-14, Northo_pass=1
+) where {ITensorT<:ITensor}
   elTA = eltype(A)
   elTphi = eltype(phi0)
 
@@ -56,12 +58,6 @@ function davidson(A, phi0::ITensorT; kwargs...) where {ITensorT<:ITensor}
   else
     phi = copy(phi0)
   end
-
-  maxiter = get(kwargs, :maxiter, 2)
-  miniter = get(kwargs, :miniter, 1)
-  errgoal = get(kwargs, :errgoal, 1E-14)
-  Northo_pass = get(kwargs, :Northo_pass, 1)
-
   approx0 = 1E-12
 
   nrm = norm(phi)

src/mps/abstractmps.jl

@@ -1966,8 +1966,7 @@ end
 
 Swap the sites `b` and `b+1`.
 """
-function swapbondsites(ψ::AbstractMPS, b::Integer; kwargs...)
-  ortho = get(kwargs, :ortho, "right")
+function swapbondsites(ψ::AbstractMPS, b::Integer; ortho="right", kwargs...)
   ψ = copy(ψ)
   if ortho == "left"
     orthocenter = b + 1

src/mps/mpo.jl

@@ -674,19 +674,25 @@ contract(ψ::MPS, A::MPO; kwargs...) = contract(A, ψ; kwargs...)
 
 #@doc (@doc contract(::MPO, ::MPS)) *(::MPO, ::MPS)
 
-function contract(::Algorithm"densitymatrix", A::MPO, ψ::MPS; kwargs...)::MPS
+function contract(
+  ::Algorithm"densitymatrix",
+  A::MPO,
+  ψ::MPS;
+  cutoff=1e-13,
+  maxdim=maxlinkdim(A) * maxlinkdim(ψ),
+  mindim=1,
+  normalize=false,
+  kwargs...,
+)::MPS
   n = length(A)
   n != length(ψ) &&
     throw(DimensionMismatch("lengths of MPO ($n) and MPS ($(length(ψ))) do not match"))
   if n == 1
     return MPS([A[1] * ψ[1]])
   end
-
+  mindim = max(mindim, 1)
+  requested_maxdim = maxdim
   ψ_out = similar(ψ)
-  cutoff::Float64 = get(kwargs, :cutoff, 1e-13)
-  requested_maxdim::Int = get(kwargs, :maxdim, maxlinkdim(A) * maxlinkdim(ψ))
-  mindim::Int = max(get(kwargs, :mindim, 1), 1)
-  normalize::Bool = get(kwargs, :normalize, false)
 
   any(i -> isempty(i), siteinds(commoninds, A, ψ)) &&
     error("In `contract(A::MPO, x::MPS)`, `A` and `x` must share a set of site indices")
@@ -719,7 +725,7 @@ function contract(::Algorithm"densitymatrix", A::MPO, ψ::MPS; kwargs...)::MPS
   ts = isnothing(l) ? "" : tags(l)
   Lis = siteinds(uniqueinds, A, ψ, n)
   Ris = siteinds(uniqueinds, simA_c, ψ_c, n)
-  F = eigen(ρ, Lis, Ris; ishermitian=true, tags=ts, kwargs...)
+  F = eigen(ρ, Lis, Ris; ishermitian=true, tags=ts, cutoff, maxdim, mindim, kwargs...)
   D, U, Ut = F.D, F.V, F.Vt
   l_renorm, r_renorm = F.l, F.r
   ψ_out[n] = Ut
@@ -739,7 +745,7 @@ function contract(::Algorithm"densitymatrix", A::MPO, ψ::MPS; kwargs...)::MPS
     ts = isnothing(l) ? "" : tags(l)
     Lis = IndexSet(s..., l_renorm)
     Ris = IndexSet(s̃..., r_renorm)
-    F = eigen(ρ, Lis, Ris; ishermitian=true, maxdim=maxdim, tags=ts, kwargs...)
+    F = eigen(ρ, Lis, Ris; ishermitian=true, tags=ts, cutoff, maxdim, mindim, kwargs...)
     D, U, Ut = F.D, F.V, F.Vt
     l_renorm, r_renorm = F.l, F.r
     ψ_out[j] = Ut
@@ -755,9 +761,7 @@ function contract(::Algorithm"densitymatrix", A::MPO, ψ::MPS; kwargs...)::MPS
   return ψ_out
 end
 
-function _contract(::Algorithm"naive", A, ψ; kwargs...)
-  truncate = get(kwargs, :truncate, true)
-
+function _contract(::Algorithm"naive", A, ψ; truncate=true, kwargs...)
   A = sim(linkinds, A)
   ψ = sim(linkinds, ψ)
 
@@ -801,16 +805,20 @@ function contract(alg::Algorithm"naive", A::MPO, B::MPO; kwargs...)
   return _contract(alg, A, B; kwargs...)
 end
 
-function contract(::Algorithm"zipup", A::MPO, B::MPO; kwargs...)
+function contract(
+  ::Algorithm"zipup",
+  A::MPO,
+  B::MPO;
+  cutoff=1e-14,
+  maxdim=maxlinkdim(A) * maxlinkdim(B),
+  mindim=1,
+  kwargs...,
+)
   if hassameinds(siteinds, A, B)
     error(
       "In `contract(A::MPO, B::MPO)`, MPOs A and B have the same site indices. The indices of the MPOs in the contraction are taken literally, and therefore they should only share one site index per site so the contraction results in an MPO. You may want to use `replaceprime(contract(A', B), 2 => 1)` or `apply(A, B)` which automatically adjusts the prime levels assuming the input MPOs have pairs of primed and unprimed indices.",
     )
   end
-  cutoff::Float64 = get(kwargs, :cutoff, 1e-14)
-  resp_degen::Bool = get(kwargs, :respect_degenerate, true)
-  maxdim::Int = get(kwargs, :maxdim, maxlinkdim(A) * maxlinkdim(B))
-  mindim::Int = max(get(kwargs, :mindim, 1), 1)
   N = length(A)
   N != length(B) &&
     throw(DimensionMismatch("lengths of MPOs A ($N) and B ($(length(B))) do not match"))
@@ -832,9 +840,9 @@ function contract(::Algorithm"zipup", A::MPO, B::MPO; kwargs...)
       left_inds;
       ortho="left",
       tags=commontags(linkinds(A, i)),
-      cutoff=cutoff,
-      maxdim=maxdim,
-      mindim=mindim,
+      cutoff,
+      maxdim,
+      mindim,
       kwargs...,
     )
     lCᵢ = dag(commoninds(C[i], R))
@@ -847,9 +855,9 @@ function contract(::Algorithm"zipup", A::MPO, B::MPO; kwargs...)
     left_inds;
     ortho="right",
     tags=commontags(linkinds(A, i)),
-    cutoff=cutoff,
-    maxdim=maxdim,
-    mindim=mindim,
+    cutoff,
+    maxdim,
+    mindim,
     kwargs...,
   )
   truncate!(C; kwargs...)

src/mps/mps.jl

@@ -970,17 +970,15 @@ dens = expect(psi, "Ntot")
 updens, dndens = expect(psi, "Nup", "Ndn") # pass more than one operator
 ```
 """
-function expect(psi::MPS, ops; kwargs...)
+function expect(psi::MPS, ops; sites=1:length(psi), site_range=nothing)
   psi = copy(psi)
   N = length(psi)
   ElT = promote_itensor_eltype(psi)
   s = siteinds(psi)
 
-  if haskey(kwargs, :site_range)
+  if !isnothing(site_range)
     @warn "The `site_range` keyword arg. to `expect` is deprecated: use the keyword `sites` instead"
-    sites = kwargs[:site_range]
-  else
-    sites = get(kwargs, :sites, 1:N)
+    sites = site_range
   end
 
   site_range = (sites isa AbstractRange) ? sites : collect(sites)

src/mps/observer.jl

@@ -176,8 +176,9 @@ function measure!(obs::DMRGObserver; kwargs...)
   end
 end
 
-function checkdone!(o::DMRGObserver; kwargs...)
-  outputlevel = get(kwargs, :outputlevel, false)
+function checkdone!(
+  o::DMRGObserver; outputlevel=false, energy=nothing, psi=nothing, sweep=nothing
+)
   if (
     length(real(energies(o))) > o.minsweeps &&
     abs(real(energies(o))[end] - real(energies(o))[end - 1]) < o.etol

src/physics/autompo/opsum_to_mpo.jl

@@ -1,10 +1,8 @@
 # `ValType::Type{<:Number}` is used instead of `ValType::Type` for efficiency, possibly due to increased method specialization.
 # See https://github.com/ITensor/ITensors.jl/pull/1183.
-function svdMPO(ValType::Type{<:Number}, os::OpSum{C}, sites; kwargs...)::MPO where {C}
-  mindim::Int = get(kwargs, :mindim, 1)
-  maxdim::Int = get(kwargs, :maxdim, 10000)
-  cutoff::Float64 = get(kwargs, :cutoff, 1E-15)
-
+function svdMPO(
+  ValType::Type{<:Number}, os::OpSum{C}, sites; mindim=1, maxdim=typemax(Int), cutoff=1e-15
+)::MPO where {C}
   N = length(sites)
 
   # Specifying the element type with `Matrix{ValType}[...]` improves type inference and therefore efficiency.