From 093fbbef731b40cb98a52e59f7b684ce2b2ad9d5 Mon Sep 17 00:00:00 2001
From: "Bowen S. Zhu" <bowenzhu@mit.edu>
Date: Sat, 25 May 2024 00:47:37 -0400
Subject: [PATCH] Add symbolic number constructor and conversion

---
 src/types.jl   | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++
 test/basics.jl | 37 ++++++++++++++++++++++++++++++++++++
 2 files changed, 88 insertions(+)

diff --git a/src/types.jl b/src/types.jl
index 2202a8df1..e10e1ddc8 100644
--- a/src/types.jl
+++ b/src/types.jl
@@ -570,6 +570,57 @@ function basic_similarterm(t, f, args, stype; metadata=nothing)
     end
 end
 
+"""
+$(TYPEDSIGNATURES)
+
+Construct a [`Symbolic`](@ref) object from a number `x`.
+
+This function is used to create a symbolic representation of a number.
+
+```jldoctest
+julia> a = SymbolicUtils.Symbolic(3.14)
+3.14
+
+julia> typeof(a)
+SymbolicUtils.BasicSymbolic{Float64}
+
+julia> b = SymbolicUtils.Symbolic{Real}(6.28)
+6.28
+
+julia> typeof(b)
+SymbolicUtils.BasicSymbolic{Real}
+```
+"""
+function Symbolic(x::T) where {T<:Number}
+    Term{T}(identity, [x])
+end
+function Symbolic{T}(x::Number) where {T}
+    Term{T}(identity, [convert(T, x)])
+end
+
+"""
+$(TYPEDSIGNATURES)
+
+Convert a number `x` to a [`Symbolic`](@ref) object.
+
+This function is used to convert a number to a symbolic representation.
+It is called, for example, when assigning to an array (converts to the array's
+element type) or assigning to a field of an object (converts to the declared type
+of the field).
+
+# Examples
+```jldoctest
+julia> a = convert(SymbolicUtils.BasicSymbolic{Real}, 3.14)
+3.14
+
+julia> typeof(a)
+SymbolicUtils.BasicSymbolic{Real}
+```
+"""
+function Base.convert(::Type{<:Symbolic{T}}, x::Number) where {T}
+    Symbolic{T}(x)
+end
+
 ###
 ### Metadata
 ###
diff --git a/test/basics.jl b/test/basics.jl
index cc3464eab..ef3b6b0e9 100644
--- a/test/basics.jl
+++ b/test/basics.jl
@@ -315,3 +315,40 @@ end
     end
     @test repr(sin(x) + sin(x)) == "sin(x) + sin(x)"
 end
+
+@testset "Symbolic Number Constructor and Conversion" begin
+    @testset "Int" begin
+        @test Symbolic(1) isa Symbolic{Int}
+        @test isequal(Symbolic(1), Symbolic{Int}(1))
+        @test isequal(convert(Symbolic{Int}, 1), Symbolic{Int}(1))
+        @test isequal(convert(BasicSymbolic{Int}, 1), Symbolic{Int}(1))
+    end
+
+    @testset "Float64" begin
+        @test Symbolic(1.0) isa Symbolic{Float64}
+        @test isequal(Symbolic(1.0), Symbolic{Float64}(1.0))
+        @test isequal(convert(Symbolic{Float64}, 1.0), Symbolic{Float64}(1.0))
+        @test isequal(convert(BasicSymbolic{Float64}, 1.0), Symbolic{Float64}(1.0))
+    end
+
+    @testset "Rational" begin
+        @test Symbolic(1//2) isa Symbolic{Rational{Int}}
+        @test isequal(Symbolic(1//2), Symbolic{Rational{Int}}(1//2))
+        @test isequal(convert(Symbolic{Rational{Int}}, 1//2), Symbolic{Rational{Int}}(1//2))
+        @test isequal(convert(BasicSymbolic{Rational{Int}}, 1//2), Symbolic{Rational{Int}}(1//2))
+    end
+
+    @testset "Complex" begin
+        @test Symbolic(1 + 2im) isa Symbolic{Complex{Int}}
+        @test isequal(Symbolic(1 + 2im), Symbolic{Complex{Int}}(1 + 2im))
+        @test isequal(convert(Symbolic{Complex{Int}}, 1 + 2im), Symbolic{Complex{Int}}(1 + 2im))
+        @test isequal(convert(BasicSymbolic{Complex{Int}}, 1 + 2im), Symbolic{Complex{Int}}(1 + 2im))
+    end
+
+    @testset "Assigning Number to Array" begin
+        @syms x y
+        arr = [x, y]
+        @test_nowarn arr[1] = 2
+        @test_nowarn arr[2] = 1.0
+    end
+end