Implement substitution to expression

ahojukka5 · Jun 22, 2020 · e714d07 · e714d07
1 parent 5812cf9
commit e714d07
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Showing 3 changed files with 13 additions and 0 deletions.
diff --git a/src/subs.jl b/src/subs.jl
@@ -6,3 +6,11 @@ function subs(s::Symbol, arg::Pair{Symbol, T}) where T <: Union{Int, Float64, Ex
     k, v = arg
     return s == k ? v : s
 end
+
+function subs(ex::Expr, arg::Pair{Symbol, T}) where T <: Union{Int, Float64, Expr}
+    ne = copy(ex)
+    for i=2:length(ne.args)
+        ne.args[i] = subs(ne.args[i], arg)
+    end
+    return ne
+end
diff --git a/test/runtests.jl b/test/runtests.jl
@@ -15,4 +15,5 @@ using SymDiff: differentiate
 
     @testset "test_subs_num.jl" begin include("test_subs_num.jl") end
     @testset "test_subs_symbol.jl" begin include("test_subs_symbol.jl") end
+    @testset "test_subs_expr.jl" begin include("test_subs_expr.jl") end
 end
diff --git a/test/test_subs_expr.jl b/test/test_subs_expr.jl
@@ -0,0 +1,4 @@
+using Test
+using SymDiff
+
+@test subs(:(1 + a + b), :a => 1) == :(1 + 1 + b)