feat(classes): support ordinary member methods and this references

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

7 files changed, 198 insertions, 0 deletions

diff --git a/tests/i/class-methods/case.json b/tests/i/class-methods/case.json
new file mode 100644
index 0000000..1f18635
--- /dev/null
+++ b/tests/i/class-methods/case.json
@@ -0,0 +1,3 @@
+{
+  "exit_code": 0
+}
diff --git a/tests/i/class-methods/expected.txt b/tests/i/class-methods/expected.txt
new file mode 100644
index 0000000..c3e4c42
--- /dev/null
+++ b/tests/i/class-methods/expected.txt
@@ -0,0 +1,9 @@
+5,8
+9,8
+9,9
+10,100
+10,7
+10,10
+caught
+42
+99
diff --git a/tests/i/class-methods/notes.md b/tests/i/class-methods/notes.md
new file mode 100644
index 0000000..903166c
--- /dev/null
+++ b/tests/i/class-methods/notes.md
@@ -0,0 +1,7 @@
+# class-methods
+
+Human review: pending. Expected output was independently traced by AI, not captured from cpsc.
+
+Basis: guide section 10.1; this and existing class value semantics are project behavior.
+
+Trace: A and B start at 3 and 8; Add changes only A to 5. Copy then Set leaves A at 9 and B at 8. Clone copies 9 into B; same-class private access reads 9. Sum(4) is 10 and the global Get returns 100. The array pointer changes Items[1] from 6 to 10; the nested object stays 7. Take adds A's 9 to Number's 1 and writes 10 into Values[1]. Fail is caught. Passing this BYREF changes A to 42. A method-only class returns 99 from its independent Get method.
diff --git a/tests/i/class-methods/program.cps b/tests/i/class-methods/program.cps
new file mode 100644
index 0000000..655fb8b
--- /dev/null
+++ b/tests/i/class-methods/program.cps
@@ -0,0 +1,89 @@
+CLASS Counter
+    PRIVATE Value : INTEGER
+    PROCEDURE Set(Number : INTEGER)
+        Value <- Number
+    ENDPROCEDURE
+    FUNCTION Get() RETURNS INTEGER
+        RETURN Value
+    ENDFUNCTION
+    PROCEDURE Add(Number : INTEGER)
+        this.Set(this.Get() + Number)
+    ENDPROCEDURE
+    PROCEDURE Copy(Other : Counter)
+        this <- Other
+    ENDPROCEDURE
+    FUNCTION Clone() RETURNS Counter
+        RETURN this
+    ENDFUNCTION
+    FUNCTION ReadOther(Other : Counter) RETURNS INTEGER
+        RETURN Other.Hidden()
+    ENDFUNCTION
+    PRIVATE FUNCTION Hidden() RETURNS INTEGER
+        RETURN Value
+    ENDFUNCTION
+    FUNCTION Sum(Number : INTEGER) RETURNS INTEGER
+        IF Number = 0 THEN
+            RETURN 0
+        ENDIF
+        RETURN Number + this.Sum(Number - 1)
+    ENDFUNCTION
+    PROCEDURE Take(BYREF Number : INTEGER, BYREF Values : ARRAY OF INTEGER)
+        Number <- Number + Value
+        Values[1] <- Number
+    ENDPROCEDURE
+    PROCEDURE Fail()
+        THROW
+    ENDPROCEDURE
+    PROCEDURE PassSelf()
+        CALL Change(this)
+    ENDPROCEDURE
+ENDCLASS
+CLASS Marker
+    FUNCTION Get() RETURNS INTEGER
+        RETURN 99
+    ENDFUNCTION
+ENDCLASS
+TYPE Container
+    DECLARE Item : Counter
+ENDTYPE
+TYPE CounterPointer = ^Counter
+PROCEDURE Change(BYREF Target : Counter)
+    Target.Set(42)
+ENDPROCEDURE
+FUNCTION Get() RETURNS INTEGER
+    RETURN 100
+ENDFUNCTION
+DECLARE A : Counter
+DECLARE B : Counter
+CALL a.sET(3)
+B.Set(8)
+A.Add(2)
+OUTPUT A.Get(), ",", B.Get()
+CALL A.Copy(B)
+A.Set(9)
+OUTPUT A.Get(), ",", B.Get()
+B <- A.Clone()
+OUTPUT B.Get(), ",", A.ReadOther(B)
+OUTPUT A.Sum(4), ",", Get()
+DECLARE Items : ARRAY[1:2] OF Counter
+Items[1].Set(6)
+DECLARE Wrapped : Container
+Wrapped.Item.Set(7)
+DECLARE P : CounterPointer
+P <- ^Items[1]
+P^.Add(4)
+OUTPUT Items[1].Get(), ",", Wrapped.Item.Get()
+DECLARE Number : INTEGER
+DECLARE Values : ARRAY[1:2] OF INTEGER
+Number <- 1
+CALL A.Take(Number, Values)
+OUTPUT Number, ",", Values[1]
+TRY
+    A.Fail()
+CATCH
+    OUTPUT "caught"
+ENDTRY
+A.PassSelf()
+OUTPUT A.Get()
+DECLARE M : Marker
+OUTPUT M.Get()
diff --git a/tests/iii/class-method-errors/case.json b/tests/iii/class-method-errors/case.json
new file mode 100644
index 0000000..655296d
--- /dev/null
+++ b/tests/iii/class-method-errors/case.json
@@ -0,0 +1,52 @@
+{
+  "errors": [
+    {
+      "reason": "Cannot redeclare this inside a method",
+      "line": 11
+    },
+    {
+      "reason": "A method parameter cannot be named this",
+      "line": 13
+    },
+    {
+      "reason": "NEW constructors are not implemented",
+      "line": 15
+    },
+    {
+      "reason": "Duplicate member set in class Box",
+      "line": 17
+    },
+    {
+      "reason": "Duplicate member Value in class Box",
+      "line": 19
+    },
+    {
+      "reason": "Cannot access private field Hidden of type Box",
+      "line": 25
+    },
+    {
+      "reason": "Cannot access private method Secret of type Box",
+      "line": 26
+    },
+    {
+      "reason": "Cannot access private method Secret of type Box",
+      "line": 30
+    },
+    {
+      "reason": "Cannot access private field Hidden of type Box",
+      "line": 31
+    },
+    {
+      "reason": "Incorrect # arguments passed to Box.Set",
+      "line": 32
+    },
+    {
+      "reason": "Type Box has no method Missing",
+      "line": 33
+    },
+    {
+      "reason": "Type INTEGER has no method Set",
+      "line": 35
+    }
+  ]
+}
diff --git a/tests/iii/class-method-errors/notes.md b/tests/iii/class-method-errors/notes.md
new file mode 100644
index 0000000..f9be5b9
--- /dev/null
+++ b/tests/iii/class-method-errors/notes.md
@@ -0,0 +1,3 @@
+# class-method-errors
+
+Reject private access from outside the owning class, duplicate members, NEW constructors, redeclarations of this, incorrect arguments and invalid receivers.
diff --git a/tests/iii/class-method-errors/program.cps b/tests/iii/class-method-errors/program.cps
new file mode 100644
index 0000000..f2503e2
--- /dev/null
+++ b/tests/iii/class-method-errors/program.cps
@@ -0,0 +1,35 @@
+CLASS Box
+    PRIVATE Hidden : INTEGER
+    PUBLIC Value : INTEGER
+    PROCEDURE Set(Number : INTEGER)
+        Hidden <- Number
+    ENDPROCEDURE
+    PRIVATE FUNCTION Secret() RETURNS INTEGER
+        RETURN Hidden
+    ENDFUNCTION
+    PROCEDURE BadLocal()
+        DECLARE this : Box
+    ENDPROCEDURE
+    PROCEDURE BadParam(this : Box)
+    ENDPROCEDURE
+    PROCEDURE NEW()
+    ENDPROCEDURE
+    PROCEDURE set()
+    ENDPROCEDURE
+    FUNCTION Value() RETURNS INTEGER
+        RETURN 0
+    ENDFUNCTION
+ENDCLASS
+CLASS Stranger
+    PROCEDURE Probe(Other : Box)
+        OUTPUT Other.Hidden
+        OUTPUT Other.Secret()
+    ENDPROCEDURE
+ENDCLASS
+DECLARE B : Box
+OUTPUT B.Secret()
+OUTPUT B.Hidden
+B.Set()
+B.Missing()
+DECLARE Number : INTEGER
+Number.Set(1)