add tests

Author: jverzani

Project.toml

@@ -29,4 +29,4 @@ Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 SymbolicUtils = "d1185830-fcd6-423d-90d6-eec64667417b"
 
 [targets]
-test = ["Test"]
+test = ["SymbolicUtils", "Test"]

test/runtests.jl

@@ -4,6 +4,7 @@ using Test
 using Serialization
 import Base: MathConstants.γ, MathConstants.e, MathConstants.φ, MathConstants.catalan
 
+VERSION >= v"1.9" && include("test-SymbolicUtils.jl")
 include("test-dense-matrix.jl")
 
 x = symbols("x")

test/test-SymbolicUtils.jl

@@ -0,0 +1,54 @@
+using Test
+using SymEngine
+import SymbolicUtils: simplify, @rule, @acrule, Chain, Fixpoint
+
+
+@testset "SymbolicUtils" begin
+    # from SymbolicUtils.jl docs
+    # https://symbolicutils.juliasymbolics.org/rewrite/#rule-based_rewriting
+    @vars w x y z
+    @vars α β
+    @vars a b c d
+
+    @test simplify(cos(x)^2 + sin(x)^2) == 1
+
+    r1 = @rule sin(2(~x)) => 2sin(~x)*cos(~x)
+    @test r1(sin(2z)) == 2*cos(z)*sin(z)
+    @test r1(sin(3z)) === nothing
+    @test r1(sin(2*(w-z))) == 2cos(w - z)*sin(w - z)
+    @test r1(sin(2*(w+z)*(α+β))) === nothing
+
+    r2 = @rule sin(~x + ~y) => sin(~x)*cos(~y) + cos(~x)*sin(~y);
+    @test r2(sin(α+β)) == sin(α)*cos(β) + cos(α)*sin(β)
+
+    xs = @rule(+(~~xs) => ~~xs)(x + y + z) # segment variable
+    @test Set(xs) == Set([x,y,z])
+
+    r3 = @rule ~x * +(~~ys) => sum(map(y-> ~x * y, ~~ys));
+    @test r3(2 * (w+w+α+β)) == 4w + 2α + 2β
+
+    r4 = @rule ~x + ~~y::(ys->iseven(length(ys))) => "odd terms"; # Predicates for matching
+
+    @test r4(a + b + c + d) == nothing
+    @test r4(b + c + d) == "odd terms"
+    @test r4(b + c + b) == nothing
+    @test r4(a + b) == nothing
+
+    sqexpand = @rule (~x + ~y)^2 => (~x)^2 + (~y)^2 + 2 * ~x * ~y
+    @test sqexpand((cos(x) + sin(x))^2) == cos(x)^2 + sin(x)^2 + 2cos(x)*sin(x)
+
+    pyid = @rule  sin(~x)^2 + cos(~x)^2  => 1
+    @test_broken pyid(cos(x)^2 + sin(x)^2) === nothing  # order should matter, but this works
+
+    acpyid = @acrule sin(~x)^2 + cos(~x)^2 => 1 # acrule is commutative
+    @test acpyid(cos(x)^2 + sin(x)^2 + 2cos(x)*sin(x)) == 1 + 2cos(x)*sin(x)
+
+    csa = Chain([sqexpand, acpyid]) # chain composes rules
+    @test csa((cos(x) + sin(x))^2)  == 1 + 2cos(x)*sin(x)
+
+    cas = Chain([acpyid, sqexpand]) # order matters
+    @test cas((cos(x) + sin(x))^2) == cos(x)^2 + sin(x)^2 + 2cos(x)*sin(x)
+
+    @test Fixpoint(cas)((cos(x) + sin(x))^2) == 1 + 2cos(x)*sin(x)
+
+end