Rename internal variables (#225)

This PR contains only a cosmetic change and makes the internal variable names consistent with the convention used by other packages, such as Julia base (`__module__` and `__source__`) and Zygote (`__context__`).

It is not strictly necessary to deprecate the current variable names since they are not exported but it seemed reasonable since probably at least `_varinfo` is known and used.

Co-authored-by: David Widmann <devmotion@users.noreply.github.com>

Author: devmotion

Project.toml

@@ -1,6 +1,6 @@
 name = "DynamicPPL"
 uuid = "366bfd00-2699-11ea-058f-f148b4cae6d8"
-version = "0.10.13"
+version = "0.10.14"
 
 [deps]
 AbstractMCMC = "80f14c24-f653-4e6a-9b94-39d6b0f70001"

src/compiler.jl

@@ -1,7 +1,8 @@
 const DISTMSG = "Right-hand side of a ~ must be subtype of Distribution or a vector of " *
     "Distributions."
 
-const INTERNALNAMES = (:_model, :_sampler, :_context, :_varinfo, :_rng)
+const INTERNALNAMES = (:__model__, :__sampler__, :__context__, :__varinfo__, :__rng__)
+const DEPRECATED_INTERNALNAMES = (:_model, :_sampler, :_context, :_varinfo, :_rng)
 
 """
     isassumption(expr)
@@ -24,7 +25,7 @@ function isassumption(expr::Union{Symbol, Expr})
         let $vn = $(varname(expr))
             # This branch should compile nicely in all cases except for partial missing data
             # For example, when `expr` is `:(x[i])` and `x isa Vector{Union{Missing, Float64}}`
-            if !$(DynamicPPL.inargnames)($vn, _model) || $(DynamicPPL.inmissings)($vn, _model)
+            if !$(DynamicPPL.inargnames)($vn, __model__) || $(DynamicPPL.inmissings)($vn, __model__)
                 true
             else
                 # Evaluate the LHS
@@ -167,10 +168,20 @@ generate_mainbody(mod, expr, warn) = generate_mainbody!(mod, Symbol[], expr, war
 
 generate_mainbody!(mod, found, x, warn) = x
 function generate_mainbody!(mod, found, sym::Symbol, warn)
+    if sym in DEPRECATED_INTERNALNAMES
+        newsym = Symbol(:_, sym, :__)
+        Base.depwarn(
+            "internal variable `$sym` is deprecated, use `$newsym` instead.",
+            :generate_mainbody!,
+        )
+        return generate_mainbody!(mod, found, newsym, warn)
+    end
+
     if warn && sym in INTERNALNAMES && sym ∉ found
-        @warn "you are using the internal variable `$(sym)`"
+        @warn "you are using the internal variable `$sym`"
         push!(found, sym)
     end
+
     return sym
 end
 function generate_mainbody!(mod, found, expr::Expr, warn)
@@ -228,18 +239,20 @@ function generate_tilde(left, right)
             $isassumption = $(DynamicPPL.isassumption(left))
             if $isassumption
                 $left = $(DynamicPPL.tilde_assume)(
-                    _rng, _context, _sampler, $tmpright, $vn, $inds, _varinfo)
+                    __rng__, __context__, __sampler__, $tmpright, $vn, $inds, __varinfo__
+                )
             else
                 $(DynamicPPL.tilde_observe)(
-                    _context, _sampler, $tmpright, $left, $vn, $inds, _varinfo)
+                    __context__, __sampler__, $tmpright, $left, $vn, $inds, __varinfo__
+                )
             end
         end
     end
 
     # If the LHS is a literal, it is always an observation
     return quote
         $(top...)
-        $(DynamicPPL.tilde_observe)(_context, _sampler, $tmpright, $left, _varinfo)
+        $(DynamicPPL.tilde_observe)(__context__, __sampler__, $tmpright, $left, __varinfo__)
     end
 end
 
@@ -263,18 +276,20 @@ function generate_dot_tilde(left, right)
             $isassumption = $(DynamicPPL.isassumption(left)) || $left === missing
             if $isassumption
                 $left .= $(DynamicPPL.dot_tilde_assume)(
-                    _rng, _context, _sampler, $tmpright, $left, $vn, $inds, _varinfo)
+                    __rng__, __context__, __sampler__, $tmpright, $left, $vn, $inds, __varinfo__
+                )
             else
                 $(DynamicPPL.dot_tilde_observe)(
-                    _context, _sampler, $tmpright, $left, $vn, $inds, _varinfo)
+                    __context__, __sampler__, $tmpright, $left, $vn, $inds, __varinfo__
+                )
             end
         end
     end
 
     # If the LHS is a literal, it is always an observation
     return quote
         $(top...)
-        $(DynamicPPL.dot_tilde_observe)(_context, _sampler, $tmpright, $left, _varinfo)
+        $(DynamicPPL.dot_tilde_observe)(__context__, __sampler__, $tmpright, $left, __varinfo__)
     end
 end
 
@@ -298,11 +313,11 @@ function build_output(modelinfo, linenumbernode)
     # Add the internal arguments to the user-specified arguments (positional + keywords).
     evaluatordef[:args] = vcat(
         [
-            :(_rng::$(Random.AbstractRNG)),
-            :(_model::$(DynamicPPL.Model)),
-            :(_varinfo::$(DynamicPPL.AbstractVarInfo)),
-            :(_sampler::$(DynamicPPL.AbstractSampler)),
-            :(_context::$(DynamicPPL.AbstractContext)),
+            :(__rng__::$(Random.AbstractRNG)),
+            :(__model__::$(DynamicPPL.Model)),
+            :(__varinfo__::$(DynamicPPL.AbstractVarInfo)),
+            :(__sampler__::$(DynamicPPL.AbstractSampler)),
+            :(__context__::$(DynamicPPL.AbstractContext)),
         ],
         modelinfo[:allargs_exprs],
     )

src/utils.jl

@@ -9,7 +9,7 @@ Add the result of the evaluation of `ex` to the joint log probability.
 """
 macro addlogprob!(ex)
     return quote
-        acclogp!($(esc(:(_varinfo))), $(esc(ex)))
+        acclogp!($(esc(:(__varinfo__))), $(esc(ex)))
     end
 end
 

test/compiler.jl

@@ -172,12 +172,12 @@ end
         # Test use of internal names
         @model function testmodel_missing3(x)
             x[1] ~ Bernoulli(0.5)
-            global varinfo_ = _varinfo
-            global sampler_ = _sampler
-            global model_ = _model
-            global context_ = _context
-            global rng_ = _rng
-            global lp = getlogp(_varinfo)
+            global varinfo_ = __varinfo__
+            global sampler_ = __sampler__
+            global model_ = __model__
+            global context_ = __context__
+            global rng_ = __rng__
+            global lp = getlogp(__varinfo__)
             return x
         end
         model = testmodel_missing3([1.0])
@@ -192,12 +192,12 @@ end
         # disable warnings
         @model function testmodel_missing4(x)
             x[1] ~ Bernoulli(0.5)
-            global varinfo_ = _varinfo
-            global sampler_ = _sampler
-            global model_ = _model
-            global context_ = _context
-            global rng_ = _rng
-            global lp = getlogp(_varinfo)
+            global varinfo_ = __varinfo__
+            global sampler_ = __sampler__
+            global model_ = __model__
+            global context_ = __context__
+            global rng_ = __rng__
+            global lp = getlogp(__varinfo__)
             return x
         end false
         lpold = lp
@@ -236,7 +236,7 @@ end
         function makemodel(p)
             @model function testmodel(x)
                 x[1] ~ Bernoulli(p)
-                global lp = getlogp(_varinfo)
+                global lp = getlogp(__varinfo__)
                 return x
             end
             return testmodel
@@ -295,11 +295,11 @@ end
 
     @testset "macros within model" begin
         # Macro expansion
-        @model function demo()
+        @model function demo1()
             @mymodel1(y ~ Uniform())
         end
 
-        @test haskey(VarInfo(demo()), @varname(x))
+        @test haskey(VarInfo(demo1()), @varname(x))
 
         # Interpolation
         # Will fail if:
@@ -308,9 +308,9 @@ end
         # 2. `@mymodel` is expanded before entire `@model` has been
         #    expanded => errors since `MyModelStruct` is not a distribution,
         #    and hence `tilde_observe` errors.
-        @model function demo()
+        @model function demo2()
             $(@mymodel2(y ~ Uniform()))
         end
-        @test demo()() == 42
+        @test demo2()() == 42
     end
 end

test/threadsafe.jl

@@ -39,7 +39,7 @@
         x = rand(10_000)
 
         @model function wthreads(x)
-            global vi_ = _varinfo
+            global vi_ = __varinfo__
             x[1] ~ Normal(0, 1)
             Threads.@threads for i in 2:length(x)
                 x[i] ~ Normal(x[i-1], 1)
@@ -70,7 +70,7 @@
                                              SampleFromPrior(), DefaultContext())
 
         @model function wothreads(x)
-            global vi_ = _varinfo
+            global vi_ = __varinfo__
             x[1] ~ Normal(0, 1)
             for i in 2:length(x)
                 x[i] ~ Normal(x[i-1], 1)

test/utils.jl

@@ -1,9 +1,9 @@
 @testset "utils.jl" begin
     @testset "addlogprob!" begin
         @model function testmodel()
-            global lp_before = getlogp(_varinfo)
+            global lp_before = getlogp(__varinfo__)
             @addlogprob!(42)
-            global lp_after = getlogp(_varinfo)
+            global lp_after = getlogp(__varinfo__)
         end
 
         model = testmodel()