From 55a00ceacb197096ed082890db9d312ed8f161d1 Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Sun, 25 Apr 2021 04:06:33 +0200
Subject: [PATCH 01/17] added PrefixContext in preparation for allowing
 submodels

---
 src/DynamicPPL.jl              |  1 +
 src/context_implementations.jl |  6 ++++++
 src/contexts.jl                | 10 ++++++++++
 3 files changed, 17 insertions(+)

diff --git a/src/DynamicPPL.jl b/src/DynamicPPL.jl
index e369fee3f..9cfecd95a 100644
--- a/src/DynamicPPL.jl
+++ b/src/DynamicPPL.jl
@@ -78,6 +78,7 @@ export  AbstractVarInfo,
         LikelihoodContext,
         PriorContext,
         MiniBatchContext,
+        PrefixContext,
         assume,
         dot_assume,
         observer,
diff --git a/src/context_implementations.jl b/src/context_implementations.jl
index 6b3542acd..61b480176 100644
--- a/src/context_implementations.jl
+++ b/src/context_implementations.jl
@@ -39,6 +39,9 @@ end
 function tilde(rng, ctx::MiniBatchContext, sampler, right, left::VarName, inds, vi)
     return tilde(rng, ctx.ctx, sampler, right, left, inds, vi)
 end
+function tilde(rng, ctx::PrefixContext, sampler, right, vn::VarName, inds, vi)
+    return tilde(rng, ctx.ctx, sampler, right, prefix(ctx, vn), inds, vi)
+end
 
 """
     tilde_assume(rng, ctx, sampler, right, vn, inds, vi)
@@ -75,6 +78,9 @@ end
 function tilde(ctx::MiniBatchContext, sampler, right, left, vi)
     return ctx.loglike_scalar * tilde(ctx.ctx, sampler, right, left, vi)
 end
+function tilde(ctx::PrefixContext, sampler, right, left, vi)
+    return tilde(ctx.ctx, sampler, right, left, vi)
+end
 
 """
     tilde_observe(ctx, sampler, right, left, vname, vinds, vi)
diff --git a/src/contexts.jl b/src/contexts.jl
index 2de05a034..26f22cf32 100644
--- a/src/contexts.jl
+++ b/src/contexts.jl
@@ -52,3 +52,13 @@ end
 function MiniBatchContext(ctx = DefaultContext(); batch_size, npoints)
     return MiniBatchContext(ctx, npoints/batch_size)
 end
+
+
+struct PrefixContext{C, Prefix} <: AbstractContext
+    ctx::C
+end
+PrefixContext{Prefix}(ctx::AbstractContext) where {Prefix} = PrefixContext{typeof(ctx), Prefix}(ctx)
+
+@generated function prefix(::PrefixContext{<:Any, Prefix}, vn::VarName{Sym}) where {Prefix, Sym}
+    return :(VarName{$(QuoteNode(Symbol(Prefix, Symbol(":"), Sym)))}(vn.indexing))
+end

From 4f0ee95814a491729dbf682b826d4f7f44052e22 Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Sun, 25 Apr 2021 04:13:48 +0200
Subject: [PATCH 02/17] added submodel macro

---
 src/DynamicPPL.jl     |  4 +++-
 src/submodel_macro.jl | 23 +++++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 src/submodel_macro.jl

diff --git a/src/DynamicPPL.jl b/src/DynamicPPL.jl
index 9cfecd95a..e00b8bba2 100644
--- a/src/DynamicPPL.jl
+++ b/src/DynamicPPL.jl
@@ -96,7 +96,9 @@ export  AbstractVarInfo,
         logjoint,
         pointwise_loglikelihoods,
 # Convenience macros
-        @addlogprob!
+        @addlogprob!,
+        @submodel
+
 
 # Reexport
 using Distributions: loglikelihood
diff --git a/src/submodel_macro.jl b/src/submodel_macro.jl
new file mode 100644
index 000000000..fc18bcde0
--- /dev/null
+++ b/src/submodel_macro.jl
@@ -0,0 +1,23 @@
+macro submodel(expr)
+    return quote
+        $(DynamicPPL)._evaluate(
+            $(esc(:_rng)),
+            $(esc(expr)),
+            $(esc(:_varinfo)),
+            $(esc(:_sampler)),
+            $(esc(:_context))
+        )
+    end
+end
+
+macro submodel(prefix, expr)
+    return quote
+        $(DynamicPPL)._evaluate(
+            $(esc(:_rng)),
+            $(esc(expr)),
+            $(esc(:_varinfo)),
+            $(esc(:_sampler)),
+            $(PrefixContext){$(esc(prefix))}($(esc(:_context)))
+        )
+    end
+end

From 2625d122e9969b10497ee1f403d09053dbf2726c Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Sun, 25 Apr 2021 05:35:57 +0200
Subject: [PATCH 03/17] forgot a QuoteNode and including the actual code

---
 src/DynamicPPL.jl     | 1 +
 src/submodel_macro.jl | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/DynamicPPL.jl b/src/DynamicPPL.jl
index e00b8bba2..fad96323d 100644
--- a/src/DynamicPPL.jl
+++ b/src/DynamicPPL.jl
@@ -126,5 +126,6 @@ include("compiler.jl")
 include("prob_macro.jl")
 include("compat/ad.jl")
 include("loglikelihoods.jl")
+include("submodel_macro.jl")
 
 end # module
diff --git a/src/submodel_macro.jl b/src/submodel_macro.jl
index fc18bcde0..dc75ed741 100644
--- a/src/submodel_macro.jl
+++ b/src/submodel_macro.jl
@@ -17,7 +17,7 @@ macro submodel(prefix, expr)
             $(esc(expr)),
             $(esc(:_varinfo)),
             $(esc(:_sampler)),
-            $(PrefixContext){$(esc(prefix))}($(esc(:_context)))
+            $(DynamicPPL).PrefixContext{$(QuoteNode(prefix))}($(esc(:_context)))
         )
     end
 end

From 52c70a5d813bb56cce899243be1e735f825a7d8a Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Sun, 25 Apr 2021 11:41:13 +0100
Subject: [PATCH 04/17] Update src/submodel_macro.jl

Co-authored-by: David Widmann <devmotion@users.noreply.github.com>
---
 src/submodel_macro.jl | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/submodel_macro.jl b/src/submodel_macro.jl
index dc75ed741..b49719907 100644
--- a/src/submodel_macro.jl
+++ b/src/submodel_macro.jl
@@ -13,11 +13,11 @@ end
 macro submodel(prefix, expr)
     return quote
         $(DynamicPPL)._evaluate(
-            $(esc(:_rng)),
+            $(esc(:__rng__)),
             $(esc(expr)),
-            $(esc(:_varinfo)),
-            $(esc(:_sampler)),
-            $(DynamicPPL).PrefixContext{$(QuoteNode(prefix))}($(esc(:_context)))
+            $(esc(:__varinfo__)),
+            $(esc(:__sampler__)),
+            $(DynamicPPL).PrefixContext{$(QuoteNode(prefix))}($(esc(:__context__)))
         )
     end
 end

From 634a2ffaedc37a4f0e4543c6ecbbb55e5f7a5238 Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Sun, 25 Apr 2021 11:41:18 +0100
Subject: [PATCH 05/17] Update src/submodel_macro.jl

Co-authored-by: David Widmann <devmotion@users.noreply.github.com>
---
 src/submodel_macro.jl | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/submodel_macro.jl b/src/submodel_macro.jl
index b49719907..309c416ba 100644
--- a/src/submodel_macro.jl
+++ b/src/submodel_macro.jl
@@ -1,11 +1,11 @@
 macro submodel(expr)
     return quote
         $(DynamicPPL)._evaluate(
-            $(esc(:_rng)),
+            $(esc(:__rng__)),
             $(esc(expr)),
-            $(esc(:_varinfo)),
-            $(esc(:_sampler)),
-            $(esc(:_context))
+            $(esc(:__varinfo__)),
+            $(esc(:__sampler__)),
+            $(esc(:__context__))
         )
     end
 end

From 267a24e2cc9ddc6bd903fc18e0d313bbe183811e Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Sun, 25 Apr 2021 12:42:38 +0200
Subject: [PATCH 06/17] added recursive constructor for PrefixContext to avoid
 runtime overhead

---
 src/contexts.jl | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/contexts.jl b/src/contexts.jl
index 26f22cf32..c79d20955 100644
--- a/src/contexts.jl
+++ b/src/contexts.jl
@@ -59,6 +59,12 @@ struct PrefixContext{C, Prefix} <: AbstractContext
 end
 PrefixContext{Prefix}(ctx::AbstractContext) where {Prefix} = PrefixContext{typeof(ctx), Prefix}(ctx)
 
+@generated function PrefixContext{PrefixInner}(
+    ctx::PrefixContext{<:Any, PrefixOuter}
+) where {PrefixInner, PrefixOuter}
+    :(PrefixContext{$(QuoteNode(Symbol(PrefixOuter, ":", PrefixInner)))}(ctx.ctx))
+end
+
 @generated function prefix(::PrefixContext{<:Any, Prefix}, vn::VarName{Sym}) where {Prefix, Sym}
     return :(VarName{$(QuoteNode(Symbol(Prefix, Symbol(":"), Sym)))}(vn.indexing))
 end

From ff539ce50e0fb3a073296a2865bf6a923ba28d53 Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Sun, 25 Apr 2021 12:43:21 +0200
Subject: [PATCH 07/17] warn is now false by default

---
 src/compiler.jl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/compiler.jl b/src/compiler.jl
index 39203f5ee..5bac0dd9c 100644
--- a/src/compiler.jl
+++ b/src/compiler.jl
@@ -43,7 +43,7 @@ isassumption(expr) = :(false)
 #################
 
 """
-    @model(expr[, warn = true])
+    @model(expr[, warn = false])
 
 Macro to specify a probabilistic model.
 
@@ -62,7 +62,7 @@ end
 
 To generate a `Model`, call `model(xvalue)` or `model(xvalue, yvalue)`.
 """
-macro model(expr, warn=true)
+macro model(expr, warn=false)
     # include `LineNumberNode` with information about the call site in the
     # generated function for easier debugging and interpretation of error messages
     esc(model(__module__, __source__, expr, warn))

From 2eb5eb438c1a2236337c62f78c83037b6c6d805b Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Sun, 25 Apr 2021 12:46:14 +0200
Subject: [PATCH 08/17] removed unnecessary module-interpolation in submodel

---
 src/submodel_macro.jl | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/submodel_macro.jl b/src/submodel_macro.jl
index 309c416ba..aa6eeb10a 100644
--- a/src/submodel_macro.jl
+++ b/src/submodel_macro.jl
@@ -1,6 +1,6 @@
 macro submodel(expr)
     return quote
-        $(DynamicPPL)._evaluate(
+        _evaluate(
             $(esc(:__rng__)),
             $(esc(expr)),
             $(esc(:__varinfo__)),
@@ -12,12 +12,12 @@ end
 
 macro submodel(prefix, expr)
     return quote
-        $(DynamicPPL)._evaluate(
+        _evaluate(
             $(esc(:__rng__)),
             $(esc(expr)),
             $(esc(:__varinfo__)),
             $(esc(:__sampler__)),
-            $(DynamicPPL).PrefixContext{$(QuoteNode(prefix))}($(esc(:__context__)))
+            PrefixContext{$(QuoteNode(prefix))}($(esc(:__context__)))
         )
     end
 end

From 902d5273268d87e9e8e9a4e71775754be860c3bc Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Sun, 25 Apr 2021 17:32:05 +0100
Subject: [PATCH 09/17] use quot instead of QuoteNode to allow interpolation in
 submodel

Co-authored-by: David Widmann <devmotion@users.noreply.github.com>
---
 src/submodel_macro.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/submodel_macro.jl b/src/submodel_macro.jl
index aa6eeb10a..abf144811 100644
--- a/src/submodel_macro.jl
+++ b/src/submodel_macro.jl
@@ -17,7 +17,7 @@ macro submodel(prefix, expr)
             $(esc(expr)),
             $(esc(:__varinfo__)),
             $(esc(:__sampler__)),
-            PrefixContext{$(QuoteNode(prefix))}($(esc(:__context__)))
+            PrefixContext{$(Meta.quot(prefix))}($(esc(:__context__)))
         )
     end
 end

From d05f080d61fa77e096959cd330524278039a6d13 Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Sun, 25 Apr 2021 17:33:30 +0100
Subject: [PATCH 10/17] change order of PrefixContext types

Co-authored-by: David Widmann <devmotion@users.noreply.github.com>
---
 src/contexts.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/contexts.jl b/src/contexts.jl
index c79d20955..4fec79f8c 100644
--- a/src/contexts.jl
+++ b/src/contexts.jl
@@ -54,7 +54,7 @@ function MiniBatchContext(ctx = DefaultContext(); batch_size, npoints)
 end
 
 
-struct PrefixContext{C, Prefix} <: AbstractContext
+struct PrefixContext{Prefix,C} <: AbstractContext
     ctx::C
 end
 PrefixContext{Prefix}(ctx::AbstractContext) where {Prefix} = PrefixContext{typeof(ctx), Prefix}(ctx)

From 13bb2599a27a8815e88c2d6e4ccb5c6a800f1d1e Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Sun, 25 Apr 2021 18:40:29 +0200
Subject: [PATCH 11/17] change ordering type-parameters for PrefixContext

---
 src/contexts.jl | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/contexts.jl b/src/contexts.jl
index 4fec79f8c..fd70d1d8e 100644
--- a/src/contexts.jl
+++ b/src/contexts.jl
@@ -54,17 +54,17 @@ function MiniBatchContext(ctx = DefaultContext(); batch_size, npoints)
 end
 
 
-struct PrefixContext{Prefix,C} <: AbstractContext
+struct PrefixContext{Prefix, C} <: AbstractContext
     ctx::C
 end
-PrefixContext{Prefix}(ctx::AbstractContext) where {Prefix} = PrefixContext{typeof(ctx), Prefix}(ctx)
+PrefixContext{Prefix}(ctx::AbstractContext) where {Prefix} = PrefixContext{Prefix, typeof(ctx)}(ctx)
 
 @generated function PrefixContext{PrefixInner}(
-    ctx::PrefixContext{<:Any, PrefixOuter}
+    ctx::PrefixContext{PrefixOuter}
 ) where {PrefixInner, PrefixOuter}
     :(PrefixContext{$(QuoteNode(Symbol(PrefixOuter, ":", PrefixInner)))}(ctx.ctx))
 end
 
-@generated function prefix(::PrefixContext{<:Any, Prefix}, vn::VarName{Sym}) where {Prefix, Sym}
+@generated function prefix(::PrefixContext{Prefix}, vn::VarName{Sym}) where {Prefix, Sym}
     return :(VarName{$(QuoteNode(Symbol(Prefix, Symbol(":"), Sym)))}(vn.indexing))
 end

From 16d4210f7dffb0254b8a634a8ac491ce95dbc1b5 Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Sun, 25 Apr 2021 18:40:45 +0200
Subject: [PATCH 12/17] escape the prefix to allow non-constant prefices

---
 src/submodel_macro.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/submodel_macro.jl b/src/submodel_macro.jl
index abf144811..267ec8933 100644
--- a/src/submodel_macro.jl
+++ b/src/submodel_macro.jl
@@ -17,7 +17,7 @@ macro submodel(prefix, expr)
             $(esc(expr)),
             $(esc(:__varinfo__)),
             $(esc(:__sampler__)),
-            PrefixContext{$(Meta.quot(prefix))}($(esc(:__context__)))
+            PrefixContext{$(esc(Meta.quot(prefix)))}($(esc(:__context__)))
         )
     end
 end

From 2c3ed9910560b38506de3bd750b6f9b478406850 Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Mon, 26 Apr 2021 02:16:17 +0200
Subject: [PATCH 13/17] use if generated for PrefixContext to allow the
 compiler to decide

---
 src/contexts.jl | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/src/contexts.jl b/src/contexts.jl
index fd70d1d8e..6871d279d 100644
--- a/src/contexts.jl
+++ b/src/contexts.jl
@@ -59,12 +59,22 @@ struct PrefixContext{Prefix, C} <: AbstractContext
 end
 PrefixContext{Prefix}(ctx::AbstractContext) where {Prefix} = PrefixContext{Prefix, typeof(ctx)}(ctx)
 
-@generated function PrefixContext{PrefixInner}(
+const _prefix_seperator = Symbol(".")
+
+function PrefixContext{PrefixInner}(
     ctx::PrefixContext{PrefixOuter}
 ) where {PrefixInner, PrefixOuter}
-    :(PrefixContext{$(QuoteNode(Symbol(PrefixOuter, ":", PrefixInner)))}(ctx.ctx))
+    if @generated
+        :(PrefixContext{$(QuoteNode(Symbol(PrefixOuter, _prefix_seperator, PrefixInner)))}(ctx.ctx))
+    else
+        PrefixContext{Symbol(PrefixOuter, _prefix_separator, PrefixInner)}(ctx.ctx)
+    end
 end
 
-@generated function prefix(::PrefixContext{Prefix}, vn::VarName{Sym}) where {Prefix, Sym}
-    return :(VarName{$(QuoteNode(Symbol(Prefix, Symbol(":"), Sym)))}(vn.indexing))
+function prefix(::PrefixContext{Prefix}, vn::VarName{Sym}) where {Prefix, Sym}
+    if @generated
+        return :(VarName{$(QuoteNode(Symbol(Prefix, _prefix_seperator, Sym)))}(vn.indexing))
+    else
+        VarName{Symbol(Prefix, _prefix_seperator, Sym)}(vn.indexing)
+    end
 end

From e0bb44973146c2cc4a1442befdced15d1f49f945 Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Mon, 26 Apr 2021 09:31:45 +0100
Subject: [PATCH 14/17] Update src/contexts.jl

Co-authored-by: David Widmann <devmotion@users.noreply.github.com>
---
 src/contexts.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/contexts.jl b/src/contexts.jl
index 6871d279d..985de641a 100644
--- a/src/contexts.jl
+++ b/src/contexts.jl
@@ -59,7 +59,7 @@ struct PrefixContext{Prefix, C} <: AbstractContext
 end
 PrefixContext{Prefix}(ctx::AbstractContext) where {Prefix} = PrefixContext{Prefix, typeof(ctx)}(ctx)
 
-const _prefix_seperator = Symbol(".")
+const PREFIX_SEPARATOR = Symbol(".")
 
 function PrefixContext{PrefixInner}(
     ctx::PrefixContext{PrefixOuter}

From d47772c98e3d18068cb3a7a339977b3677b51a29 Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Mon, 26 Apr 2021 10:32:52 +0200
Subject: [PATCH 15/17] _prefix_separator is now named PREFIX_SEPARATOR

---
 src/contexts.jl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/contexts.jl b/src/contexts.jl
index 985de641a..0d7006bf0 100644
--- a/src/contexts.jl
+++ b/src/contexts.jl
@@ -67,7 +67,7 @@ function PrefixContext{PrefixInner}(
     if @generated
         :(PrefixContext{$(QuoteNode(Symbol(PrefixOuter, _prefix_seperator, PrefixInner)))}(ctx.ctx))
     else
-        PrefixContext{Symbol(PrefixOuter, _prefix_separator, PrefixInner)}(ctx.ctx)
+        PrefixContext{Symbol(PrefixOuter, PREFIX_SEPARATOR, PrefixInner)}(ctx.ctx)
     end
 end
 
@@ -75,6 +75,6 @@ function prefix(::PrefixContext{Prefix}, vn::VarName{Sym}) where {Prefix, Sym}
     if @generated
         return :(VarName{$(QuoteNode(Symbol(Prefix, _prefix_seperator, Sym)))}(vn.indexing))
     else
-        VarName{Symbol(Prefix, _prefix_seperator, Sym)}(vn.indexing)
+        VarName{Symbol(Prefix, PREFIX_SEPARATOR, Sym)}(vn.indexing)
     end
 end

From cdd2543b6a2ab0516240410d1e6faa28bad6238e Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Sun, 16 May 2021 05:11:57 +0200
Subject: [PATCH 16/17] added tests for submodel macro

---
 test/compiler.jl | 101 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)

diff --git a/test/compiler.jl b/test/compiler.jl
index 73901dae7..841ccdef4 100644
--- a/test/compiler.jl
+++ b/test/compiler.jl
@@ -313,4 +313,105 @@ end
         end
         @test demo2()() == 42
     end
+
+    @testset "submodel" begin
+        # No prefix, 1 level.
+        @model function demo1(x)
+            x ~ Normal()
+        end;
+        @model function demo2(x, y)
+            @submodel demo1(x)
+            y ~ Uniform()
+        end;
+        # No observation.
+        m = demo2(missing, missing);
+        vi = VarInfo(m);
+        ks = keys(vi)
+        @test VarName(:x) ∈ ks
+        @test VarName(:y) ∈ ks
+
+        # Observation in top-level.
+        m = demo2(missing, 1.0);
+        vi = VarInfo(m);
+        ks = keys(vi)
+        @test VarName(:x) ∈ ks
+        @test VarName(:y) ∉ ks
+
+        # Observation in nested model.
+        m = demo2(1000.0, missing);
+        vi = VarInfo(m);
+        ks = keys(vi)
+        @test VarName(:x) ∉ ks
+        @test VarName(:y) ∈ ks
+
+        # Observe all.
+        m = demo2(1000.0, 0.5);
+        vi = VarInfo(m);
+        ks = keys(vi)
+        @test isempty(ks)
+
+        # Check values makes sense.
+        @model function demo2(x, y)
+            @submodel demo1(x)
+            y ~ Normal(x)
+        end;
+        m = demo2(1000.0, missing);
+        # Mean of `y` should be close to 1000.
+        @test abs(mean([VarInfo(m)[VarName(:y)] for i = 1:10]) - 1000) ≤ 10;
+
+        # Prefixed submodels and usage of submodel return values.
+        @model function demo_return(x)
+            x ~ Normal()
+            return x
+        end;
+
+        @model function demo_useval(x, y)
+            x1 = @submodel sub1 demo_return(x)
+            x2 = @submodel sub2 demo_return(y)
+
+            z ~ Normal(x1 + x2 + 100, 1.0)
+        end;
+        m = demo_useval(missing, missing)
+        vi = VarInfo(m);
+        ks = keys(vi)
+        @test VarName(Symbol("sub1.x")) ∈ ks
+        @test VarName(Symbol("sub2.x")) ∈ ks
+        @test VarName(:z) ∈ ks
+        @test abs(mean([VarInfo(m)[VarName(:z)] for i = 1:10]) - 100) ≤ 10
+
+        # AR1 model. Dynamic prefixing.
+        @model function AR1(num_steps, α, μ, σ, ::Type{TV} = Vector{Float64}) where {TV}
+            η ~ MvNormal(num_steps, 1.0)
+            δ = sqrt(1 - α^2)
+
+            x = TV(undef, num_steps)
+            x[1] = η[1]
+            @inbounds for t = 2:num_steps
+                x[t] = @. α * x[t - 1] + δ * η[t]
+            end
+
+            return @. μ + σ * x
+        end
+
+        @model function demo(y)
+            α ~ Uniform()
+            μ ~ Normal()
+            σ ~ truncated(Normal(), 0, Inf)
+
+            num_steps = length(y[1])
+            num_obs = length(y)
+            @inbounds for i = 1:num_obs
+                x = @submodel $(Symbol("ar1_$i")) AR1(num_steps, α, μ, σ)
+                y[i] ~ MvNormal(x, 0.1)
+            end
+        end;
+
+        ys = [randn(10), randn(10)];
+        m = demo(ys);
+        vi = VarInfo(m);
+
+        for k in [:α, :μ, :σ, Symbol("ar1_1.η"), Symbol("ar1_2.η")]
+            @test VarName(k) ∈ keys(vi)
+        end
+    end
 end

From 46cdcb153129c200a05918ceb41fc884e2bba86f Mon Sep 17 00:00:00 2001
From: Tor Erlend Fjelde <tor.erlend95@gmail.com>
Date: Tue, 18 May 2021 14:25:57 +0200
Subject: [PATCH 17/17] version bump

---
 Project.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Project.toml b/Project.toml
index e1a1fddac..201dd62d9 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "DynamicPPL"
 uuid = "366bfd00-2699-11ea-058f-f148b4cae6d8"
-version = "0.10.19"
+version = "0.10.20"
 
 [deps]
 AbstractMCMC = "80f14c24-f653-4e6a-9b94-39d6b0f70001"