Fix quoted property access syntax (e.g., Core.:(!==)) (#89)

* Fix quoted property access syntax (e.g., `Core.:(!==)`)

Handle `K"quote"` nodes in property access during macro expansion by
unwrapping them before processing. This allows syntax like
`Core.:(!==)` to lower correctly, matching the behavior of `Meta.lower`.

Co-Authored-By: Claude <[email protected]>

Author: aviatesk

src/macro_expansion.jl

@@ -458,7 +458,13 @@ function expand_forms_1(ctx::MacroExpansionContext, ex::SyntaxTree)
     elseif k == K"module" || k == K"toplevel" || k == K"inert"
         ex
     elseif k == K"." && numchildren(ex) == 2
-        e2 = expand_forms_1(ctx, ex[2])
+        # Handle quoted property access like `x.:(foo)` or `Core.:(!==)`
+        # Unwrap the quote to get the identifier before expansion
+        rhs = ex[2]
+        if kind(rhs) == K"quote" && numchildren(rhs) == 1
+            rhs = rhs[1]
+        end
+        e2 = expand_forms_1(ctx, rhs)
         if kind(e2) == K"Identifier" || kind(e2) == K"Placeholder"
             # FIXME: Do the K"Symbol" transformation in the parser??
             e2 = @ast ctx e2 e2=>K"Symbol"

test/quoting.jl

@@ -94,6 +94,33 @@ end
 @test kind(ex[2]) == K"Identifier"
 @test ex[2].name_val == "a"
 
+# Test quoted property access syntax like `Core.:(foo)` and `Core.:(!==)`
+@test JuliaLowering.include_string(test_mod, """
+    x = (a=1, b=2)
+    x.:(a)
+""") == 1
+@test JuliaLowering.include_string(test_mod, """
+    Core.:(!==)
+""") === (!==)
+
+# Test quoted operator function definitions (issue #20)
+@test JuliaLowering.include_string(test_mod, """
+begin
+    struct Issue20
+        x::Int
+    end
+    Base.:(==)(a::Issue20, b::Issue20) = a.x == b.x
+    Issue20(1) == Issue20(1)
+end
+""") === true
+
+@test JuliaLowering.include_string(test_mod, """
+begin
+    Base.:(<)(a::Issue20, b::Issue20) = a.x < b.x
+    Issue20(1) < Issue20(2)
+end
+""") === true
+
 # interpolations at multiple depths
 ex = JuliaLowering.include_string(test_mod, raw"""
 let

test/quoting_ir.jl

@@ -42,3 +42,36 @@ quote
     $$x + 1
 #    └┘ ── `$` expression outside string or quote block
 end
+
+########################################
+# Quoted property access with identifier
+Core.:(foo)
+#---------------------
+1   TestMod.Core
+2   (call top.getproperty %₁ :foo)
+3   (return %₂)
+
+########################################
+# Quoted property access with operator
+Core.:(!==)
+#---------------------
+1   TestMod.Core
+2   (call top.getproperty %₁ :!==)
+3   (return %₂)
+
+########################################
+# Quoted operator function definition (issue #20)
+function Base.:(==)() end
+#---------------------
+1   TestMod.Base
+2   (call top.getproperty %₁ :==)
+3   (call core.Typeof %₂)
+4   (call core.svec %₃)
+5   (call core.svec)
+6   SourceLocation::1:10
+7   (call core.svec %₄ %₅ %₆)
+8   --- method core.nothing %₇
+    slots: [slot₁/#self#(!read)]
+    1   (return core.nothing)
+9   latestworld
+10  (return core.nothing)