Convert PrettyTables to a package extension

- Made PrettyTables a weak dependency in Project.toml
- Created SymbolicIndexingInterfacePrettyTablesExt extension
- Moved PrettyTables-dependent code to the extension
- Added fallback implementation for show_params when PrettyTables is not loaded
- Extension properly overrides the fallback when PrettyTables is available

The package now works without PrettyTables as a hard dependency,
but provides enhanced table formatting when PrettyTables is installed.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: ChrisRackauckas

Project.toml

@@ -6,10 +6,15 @@ version = "0.3.42"
 [deps]
 Accessors = "7d9f7c33-5ae7-4f3b-8dc6-eff91059b697"
 ArrayInterface = "4fba245c-0d91-5ea0-9b3e-6abc04ee57a9"
-PrettyTables = "08abe8d2-0d0c-5749-adfa-8a2ac140af0d"
 RuntimeGeneratedFunctions = "7e49a35a-f44a-4d26-94aa-eba1b4ca6b47"
 StaticArraysCore = "1e83bf80-4336-4d27-bf5d-d5a4f845583c"
 
+[weakdeps]
+PrettyTables = "08abe8d2-0d0c-5749-adfa-8a2ac140af0d"
+
+[extensions]
+SymbolicIndexingInterfacePrettyTablesExt = "PrettyTables"
+
 [compat]
 Accessors = "0.1.36"
 Aqua = "0.8"

ext/SymbolicIndexingInterfacePrettyTablesExt/SymbolicIndexingInterfacePrettyTablesExt.jl

@@ -0,0 +1,50 @@
+module SymbolicIndexingInterfacePrettyTablesExt
+
+__precompile__(false)
+
+using SymbolicIndexingInterface
+using SymbolicIndexingInterface: ParameterIndexingProxy, parameter_symbols, symbolic_type,
+                                 ArraySymbolic, getp
+using PrettyTables
+
+# Override the fallback implementation with the PrettyTables version
+function SymbolicIndexingInterface.show_params(
+        io::IO, pip::ParameterIndexingProxy; num_rows = 20,
+        show_all = false, scalarize = true, kwargs...)
+    params = Any[]
+    vals = Any[]
+    for p in parameter_symbols(pip.wrapped)
+        if symbolic_type(p) === ArraySymbolic() && scalarize
+            val = getp(pip.wrapped, p)(pip.wrapped)
+            for (_p, _v) in zip(collect(p), val)
+                push!(params, _p)
+                push!(vals, _v)
+            end
+        else
+            push!(params, p)
+            val = getp(pip.wrapped, p)(pip.wrapped)
+            push!(vals, val)
+        end
+    end
+
+    num_shown = if show_all
+        length(params)
+    else
+        if num_rows > length(params)
+            length(params)
+        else
+            num_rows
+        end
+    end
+
+    pretty_table(io, [params[1:num_shown] vals[1:num_shown]];
+        header = ["Parameter", "Value"],
+        kwargs...)
+
+    if num_shown < length(params)
+        println(io,
+            "$num_shown of $(length(params)) params shown. To show all the parameters, call `show_params(io, ps, show_all = true)`. Adjust the number of rows with the num_rows kwarg. Consult `show_params` docstring for more options.")
+    end
+end
+
+end

src/SymbolicIndexingInterface.jl

@@ -4,7 +4,6 @@ using RuntimeGeneratedFunctions
 import StaticArraysCore: MArray, similar_type
 import ArrayInterface
 using Accessors: @reset
-using PrettyTables # for pretty printing
 
 RuntimeGeneratedFunctions.init(@__MODULE__)
 

src/parameter_indexing_proxy.jl

@@ -29,8 +29,11 @@ Method for customizing the table output. Keyword args:
 - num_rows
 - show_all: whether to show all parameters. Overrides `num_rows`.
 - scalarize: whether to scalarize array symbolics in the table output.
-- kwargs... are passed to the pretty_table call.
+- kwargs... are passed to the pretty_table call (if PrettyTables is loaded).
 """
+function show_params end
+
+# Fallback implementation when PrettyTables is not loaded
 function show_params(io::IO, pip::ParameterIndexingProxy; num_rows = 20,
         show_all = false, scalarize = true, kwargs...)
     params = Any[]
@@ -59,9 +62,14 @@ function show_params(io::IO, pip::ParameterIndexingProxy; num_rows = 20,
         end
     end
 
-    pretty_table(io, [params[1:num_shown] vals[1:num_shown]];
-        header = ["Parameter", "Value"],
-        kwargs...)
+    # Fallback implementation without PrettyTables
+    println(io, "Parameter Indexing Proxy")
+    println(io, "=" ^ 50)
+    println(io, "Parameter                | Value")
+    println(io, "-" ^ 50)
+    for i in 1:num_shown
+        println(io, rpad(string(params[i]), 24) * " | " * string(vals[i]))
+    end
 
     if num_shown < length(params)
         println(io,