Make JSON + StanLogDensityProblems direct deps, fix deanon_size for compound expressions

- Move StanLogDensityProblems from weakdeps to deps, remove extension
- Move instantiate implementation from ext into stan module
- Make deanon_size recursive to handle compound size expressions (e.g. _arg1 + _arg2)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: nsiccha

Project.toml

@@ -9,6 +9,7 @@ JSON = "682c06a0-de6a-54ab-a142-c8b1cf79cde6"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 LogExpFunctions = "2ab3a3ac-af41-5b50-aa03-7779005ae688"
 OrderedCollections = "bac558e1-5e72-5ebc-8fee-abe8a469f55d"
+StanLogDensityProblems = "a545de4d-8dba-46db-9d34-4e41d3f07807"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 
 [weakdeps]
@@ -18,7 +19,6 @@ Markdown = "d6f4376e-aef5-505a-96c1-9c027394607a"
 Mooncake = "da2b9cff-9c12-43a0-ae48-6db2b0edb7d6"
 OrdinaryDiffEq = "1dea7af3-3e70-54e6-95c3-0bf5283fa5ed"
 PosteriorDB = "1c4bc282-d2f5-44f9-b6d1-8c4424a23ad4"
-StanLogDensityProblems = "a545de4d-8dba-46db-9d34-4e41d3f07807"
 
 [extensions]
 DifferentiationInterfaceExt = "DifferentiationInterface"
@@ -27,7 +27,6 @@ MarkdownExt = "Markdown"
 MooncakeExt = "Mooncake"
 OrdinaryDiffEqExt = "OrdinaryDiffEq"
 PosteriorDBExt = "PosteriorDB"
-StanLogDensityProblemsExt = "StanLogDensityProblems"
 
 [sources]
 TestModules = {url = "https://github.com/nsiccha/TestModules.jl"}

ext/StanLogDensityProblemsExt.jl

@@ -5,7 +5,7 @@ export @slic, @defsig, @deffun
 export stan_code, stan_model, stan_instantiate
 export StanBlocksError
 
-using LinearAlgebra, Statistics, Distributions, LogExpFunctions, JSON
+using LinearAlgebra, Statistics, Distributions, LogExpFunctions, JSON, StanLogDensityProblems
 
 # --- Error type for StanBlocks computations (defined early so submodules can use it) ---
 

src/StanBlocks.jl

@@ -1,5 +1,5 @@
 module stan
-using OrderedCollections
+using OrderedCollections, JSON, StanLogDensityProblems
 const RV_NAME = gensym("RV")
 dumperror(x) = (dump(x); error(x))
 """
@@ -544,11 +544,17 @@ forward!(x::StringExpr; info) = join(map(stan_code, forward!(x.args; info)))
 deanon_size(s, x) = s
 deanon_size(s::StanExpr, x::CanonicalExpr) = begin
     e = expr(s)
-    isa(e, Symbol) || return s
-    m = match(r"^_arg(\d+)$", string(e))
-    isnothing(m) && return s
-    i = parse(Int, m[1])
-    i <= length(x.args) ? x.args[i] : s
+    if isa(e, Symbol)
+        m = match(r"^_arg(\d+)$", string(e))
+        isnothing(m) && return s
+        i = parse(Int, m[1])
+        return i <= length(x.args) ? x.args[i] : s
+    elseif isa(e, CanonicalExpr)
+        new_args = map(a -> deanon_size(a, x), e.args)
+        new_args == e.args && return s
+        return StanExpr(remake(e, new_args...), type(s))
+    end
+    s
 end
 deanon_type(tt::StanType, x::CanonicalExpr) = begin
     sz = stan_size(tt)
@@ -995,12 +1001,24 @@ prepare_for_stan(x::Tuple) = prepare_for_stan(Dict(enumerate(x)))
 bridgestan_data(x::Dict) = JSON.json(prepare_for_stan(x))
 """
 Returns the StanLogDensityProblem (a compiled posterior).
-
-**Warning:**
-
-Requires loading StanLogDensityProblems.jl and JSON.jl.
 """
-instantiate(args...; kwargs...) = error("Using instantiate requires loading StanLogDensityProblems.jl and JSON.jl!")
+instantiate(x::Union{SlicModel,StanModel}; nan_on_error=true, make_args=["STAN_THREADS=true"], warn=false, kwargs...) = begin
+    sc = stan_code(x)
+    stan_path = get(kwargs, :path, joinpath("tmp", string(hash(sc)) * ".stan"))
+    mkpath(dirname(stan_path))
+    if !isfile(stan_path)
+        open(stan_path, "w") do fd
+            write(fd, sc)
+        end
+    end
+    StanLogDensityProblems.StanProblem(
+        stan_path,
+        bridgestan_data(stan_data(x));
+        nan_on_error,
+        make_args,
+        warn
+    )
+end
 debug_instantiate(x; kwargs...) = instantiate(x; nan_on_error=false, kwargs...)
 passinstantiate(x; kwargs...) = (instantiate(x; kwargs...); x)
 stan_data(x::SlicModel) = stan_data(stan_model(x))