feat(operators): add member and unary overloads with explicit calls

Select member and global candidates together, enforce private access, and
reuse argument marshalling. Materialize temporary receivers for chaining
and register them for the existing object cleanup mechanism.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

7 files changed, 127 insertions, 0 deletions

diff --git a/tests/i/operator-members/case.json b/tests/i/operator-members/case.json
new file mode 100644
index 0000000..0967ef4
--- /dev/null
+++ b/tests/i/operator-members/case.json
@@ -0,0 +1 @@
+{}
diff --git a/tests/i/operator-members/expected.txt b/tests/i/operator-members/expected.txt
new file mode 100644
index 0000000..24ab52b
--- /dev/null
+++ b/tests/i/operator-members/expected.txt
@@ -0,0 +1,12 @@
+9
+-3
+negated
+3!
+8
+8
+8
+6
+make
+number
+6
+caught
diff --git a/tests/i/operator-members/notes.md b/tests/i/operator-members/notes.md
new file mode 100644
index 0000000..2b741c9
--- /dev/null
+++ b/tests/i/operator-members/notes.md
@@ -0,0 +1,7 @@
+# operator-members
+
+Human review: pending. Expected output was independently traced by AI, not captured from cpsc.
+
+Basis: operator overloading is a project extension; arguments match exact types.
+
+Trace: chained additions produce 3 + 2 + 4 = 9. Unary minus returns -3; NOT deliberately returns negated. A method can use its private concatenation operator, yielding 3!. Box addition modifies the original receiver from 3 to 8. Explicit member addition then global subtraction yields 8; explicit global subtraction yields 6. Discarded unary/global calls produce no output. MakeBox prints make exactly once, then Number prints number exactly once; their result has value 4 + 2 = 6. A throwing global multiplication reaches CATCH.
diff --git a/tests/i/operator-members/program.cps b/tests/i/operator-members/program.cps
new file mode 100644
index 0000000..d17184c
--- /dev/null
+++ b/tests/i/operator-members/program.cps
@@ -0,0 +1,66 @@
+CLASS Box
+Value : INTEGER
+OVERLOAD FUNCTION OPERATOR+(rhs : INTEGER) RETURNS Box
+DECLARE result : Box
+result.Value <- Value + rhs
+RETURN result
+ENDFUNCTION
+OVERLOAD FUNCTION OPERATOR+(rhs : Box) RETURNS INTEGER
+Value <- Value + rhs.Value
+RETURN Value
+ENDFUNCTION
+OVERLOAD FUNCTION OPERATOR-() RETURNS INTEGER
+RETURN -Value
+ENDFUNCTION
+OVERLOAD FUNCTION OPERATOR NOT() RETURNS STRING
+RETURN "negated"
+ENDFUNCTION
+PRIVATE OVERLOAD FUNCTION OPERATOR&(rhs : STRING) RETURNS STRING
+RETURN NUM_TO_STR(Value) & rhs
+ENDFUNCTION
+FUNCTION Describe() RETURNS STRING
+RETURN this & "!"
+ENDFUNCTION
+ENDCLASS
+OVERLOAD FUNCTION OPERATOR-(lhs : Box, rhs : INTEGER) RETURNS INTEGER
+RETURN lhs.Value - rhs
+ENDFUNCTION
+OVERLOAD FUNCTION OPERATOR*(lhs : Box, rhs : Box) RETURNS INTEGER
+THROW
+RETURN 0
+ENDFUNCTION
+FUNCTION MakeBox() RETURNS Box
+OUTPUT "make"
+DECLARE result : Box
+result.Value <- 4
+RETURN result
+ENDFUNCTION
+FUNCTION Number() RETURNS INTEGER
+OUTPUT "number"
+RETURN 2
+ENDFUNCTION
+DECLARE a : Box
+DECLARE b : Box
+DECLARE result : Box
+a.Value <- 3
+b.Value <- 5
+result <- (a + 2) + 4
+OUTPUT result.Value
+OUTPUT -a
+OUTPUT NOT a
+OUTPUT a.Describe()
+OUTPUT a + b
+OUTPUT a.Value
+OUTPUT a.OPERATOR+(1) - 1
+OUTPUT OPERATOR-(a, 2)
+CALL a.OPERATOR-( )
+a.OPERATOR-( )
+CALL OPERATOR-(a, 1)
+OPERATOR-(a, 1)
+result <- MakeBox() + Number()
+OUTPUT result.Value
+TRY
+OUTPUT a * b
+CATCH
+OUTPUT "caught"
+ENDTRY
diff --git a/tests/iii/operator-member-errors/case.json b/tests/iii/operator-member-errors/case.json
new file mode 100644
index 0000000..1e8f8ae
--- /dev/null
+++ b/tests/iii/operator-member-errors/case.json
@@ -0,0 +1,20 @@
+{
+  "errors": [
+    {
+      "reason": "Ambiguous overload",
+      "line": 14
+    },
+    {
+      "reason": "Cannot access private method",
+      "line": 15
+    },
+    {
+      "reason": "Cannot access private method",
+      "line": 16
+    },
+    {
+      "reason": "whole array cannot be used as an operand",
+      "line": 18
+    }
+  ]
+}
diff --git a/tests/iii/operator-member-errors/notes.md b/tests/iii/operator-member-errors/notes.md
new file mode 100644
index 0000000..204ab43
--- /dev/null
+++ b/tests/iii/operator-member-errors/notes.md
@@ -0,0 +1,3 @@
+# operator-member-errors
+
+Reject equally matching member/global candidates, implicit and explicit private access, and unary operations on whole arrays.
diff --git a/tests/iii/operator-member-errors/program.cps b/tests/iii/operator-member-errors/program.cps
new file mode 100644
index 0000000..9b48135
--- /dev/null
+++ b/tests/iii/operator-member-errors/program.cps
@@ -0,0 +1,18 @@
+CLASS Box
+Value : INTEGER
+OVERLOAD FUNCTION OPERATOR+(rhs : Box) RETURNS INTEGER
+RETURN 1
+ENDFUNCTION
+PRIVATE OVERLOAD FUNCTION OPERATOR&(rhs : STRING) RETURNS STRING
+RETURN rhs
+ENDFUNCTION
+ENDCLASS
+OVERLOAD FUNCTION OPERATOR+(lhs : Box, rhs : Box) RETURNS INTEGER
+RETURN 2
+ENDFUNCTION
+DECLARE a : Box
+OUTPUT a + a
+OUTPUT a & "x"
+OUTPUT a.OPERATOR&("x")
+DECLARE items : ARRAY[1:2] OF Box
+OUTPUT NOT items