feat(types): support implicit single-argument constructors

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

8 files changed, 189 insertions, 0 deletions

diff --git a/tests/i/implicit-constructors/case.json b/tests/i/implicit-constructors/case.json
new file mode 100644
index 0000000..0967ef4
--- /dev/null
+++ b/tests/i/implicit-constructors/case.json
@@ -0,0 +1 @@
+{}
diff --git a/tests/i/implicit-constructors/expected.txt b/tests/i/implicit-constructors/expected.txt
new file mode 100644
index 0000000..d360ce8
--- /dev/null
+++ b/tests/i/implicit-constructors/expected.txt
@@ -0,0 +1,5 @@
+7:8:201:6:9
+9
+TRUE
+0
+0
diff --git a/tests/i/implicit-constructors/notes.md b/tests/i/implicit-constructors/notes.md
new file mode 100644
index 0000000..cdcab87
--- /dev/null
+++ b/tests/i/implicit-constructors/notes.md
@@ -0,0 +1,3 @@
+# Implicit constructors
+
+Pending human review. Box counts constructions, copies and destruction. Assignments, BYVAL arguments, RETURN, operators and CASE use its INTEGER conversion. Pick selects its exact INTEGER overload. Exercise releases all objects; a later failing argument releases the pending converted Box before CATCH.
diff --git a/tests/i/implicit-constructors/program.cps b/tests/i/implicit-constructors/program.cps
new file mode 100644
index 0000000..d13236e
--- /dev/null
+++ b/tests/i/implicit-constructors/program.cps
@@ -0,0 +1,63 @@
+GLOBAL
+    DECLARE Alive : INTEGER
+ENDGLOBAL
+CLASS Box
+    Value : INTEGER
+    OVERLOAD PROCEDURE NEW()
+        Alive <- Alive + 1
+    ENDPROCEDURE
+    OVERLOAD IMPLICIT PROCEDURE NEW(Number : INTEGER)
+        Value <- Number
+        Alive <- Alive + 1
+    ENDPROCEDURE
+    OVERLOAD PROCEDURE NEW(BYREF Other : Box)
+        Value <- Other.Value
+        Alive <- Alive + 1
+    ENDPROCEDURE
+    PROCEDURE DELETE()
+        Alive <- Alive - 1
+    ENDPROCEDURE
+ENDCLASS
+FUNCTION Read(Value : Box) RETURNS INTEGER
+    RETURN Value.Value
+ENDFUNCTION
+OVERLOAD FUNCTION Pick(Value : Box) RETURNS INTEGER
+    RETURN 100 + Value.Value
+ENDFUNCTION
+OVERLOAD FUNCTION Pick(Value : INTEGER) RETURNS INTEGER
+    RETURN 200 + Value
+ENDFUNCTION
+OVERLOAD FUNCTION Only(Value : Box) RETURNS INTEGER
+    RETURN Value.Value
+ENDFUNCTION
+OVERLOAD FUNCTION OPERATOR+(A : Box, B : Box) RETURNS INTEGER
+    RETURN A.Value + B.Value
+ENDFUNCTION
+OVERLOAD FUNCTION OPERATOR=(A : Box, B : Box) RETURNS BOOLEAN
+    RETURN A.Value = B.Value
+ENDFUNCTION
+FUNCTION Make() RETURNS Box
+    RETURN 9
+ENDFUNCTION
+PROCEDURE Exercise()
+    DECLARE B : Box
+    B <- 7
+    OUTPUT B.Value, ":", Read(8), ":", Pick(1), ":", Only(6), ":", B + 2
+    OUTPUT Read(Make())
+    CASE OF B
+        7 : OUTPUT TRUE
+        OTHERWISE : OUTPUT FALSE
+    ENDCASE
+ENDPROCEDURE
+FUNCTION Fail() RETURNS INTEGER
+    THROW
+ENDFUNCTION
+PROCEDURE Pair(Value : Box, Number : INTEGER)
+ENDPROCEDURE
+CALL Exercise()
+OUTPUT Alive
+TRY
+    CALL Pair(1, Fail())
+CATCH
+    OUTPUT Alive
+ENDTRY
diff --git a/tests/iii/implicit-conversion-errors/case.json b/tests/iii/implicit-conversion-errors/case.json
new file mode 100644
index 0000000..a004af2
--- /dev/null
+++ b/tests/iii/implicit-conversion-errors/case.json
@@ -0,0 +1,24 @@
+{
+  "errors": [
+    {
+      "line": 28,
+      "reason": "Cannot use a value of type INTEGER where ExplicitOnly is expected"
+    },
+    {
+      "line": 29,
+      "reason": "Cannot use a value of type INTEGER where Second is expected"
+    },
+    {
+      "line": 30,
+      "reason": "BYREF argument I to Ref must be of type First"
+    },
+    {
+      "line": 41,
+      "reason": "Ambiguous call to Ambiguous"
+    },
+    {
+      "line": 48,
+      "reason": "Cannot access private method NEW"
+    }
+  ]
+}
diff --git a/tests/iii/implicit-conversion-errors/program.cps b/tests/iii/implicit-conversion-errors/program.cps
new file mode 100644
index 0000000..6297b16
--- /dev/null
+++ b/tests/iii/implicit-conversion-errors/program.cps
@@ -0,0 +1,48 @@
+CLASS ExplicitOnly
+    Value : INTEGER
+    PROCEDURE NEW(Number : INTEGER)
+        Value <- Number
+    ENDPROCEDURE
+ENDCLASS
+CLASS First
+    Value : INTEGER
+    IMPLICIT PROCEDURE NEW(Number : INTEGER)
+        Value <- Number
+    ENDPROCEDURE
+ENDCLASS
+CLASS Second
+    Value : INTEGER
+    IMPLICIT PROCEDURE NEW(Other : First)
+        Value <- Other.Value
+    ENDPROCEDURE
+ENDCLASS
+OVERLOAD PROCEDURE Choose(Value : First)
+ENDPROCEDURE
+OVERLOAD PROCEDURE Choose(Value : Second)
+ENDPROCEDURE
+PROCEDURE Ref(BYREF Value : First)
+ENDPROCEDURE
+DECLARE E : ExplicitOnly(1)
+DECLARE S : Second
+DECLARE I : INTEGER
+E <- 1
+S <- 1
+CALL Ref(I)
+CLASS Alternative
+    Value : INTEGER
+    IMPLICIT PROCEDURE NEW(Number : INTEGER)
+        Value <- Number
+    ENDPROCEDURE
+ENDCLASS
+OVERLOAD PROCEDURE Ambiguous(Value : First)
+ENDPROCEDURE
+OVERLOAD PROCEDURE Ambiguous(Value : Alternative)
+ENDPROCEDURE
+CALL Ambiguous(1)
+CLASS Hidden
+    PRIVATE IMPLICIT PROCEDURE NEW(Number : INTEGER)
+    ENDPROCEDURE
+ENDCLASS
+PROCEDURE HiddenArg(Value : Hidden)
+ENDPROCEDURE
+CALL HiddenArg(1)
diff --git a/tests/iii/implicit-declaration-errors/case.json b/tests/iii/implicit-declaration-errors/case.json
new file mode 100644
index 0000000..3968b70
--- /dev/null
+++ b/tests/iii/implicit-declaration-errors/case.json
@@ -0,0 +1,24 @@
+{
+  "errors": [
+    {
+      "line": 2,
+      "reason": "IMPLICIT requires a CLASS constructor NEW with one BYVAL non-array parameter"
+    },
+    {
+      "line": 6,
+      "reason": "IMPLICIT requires a CLASS constructor NEW with one BYVAL non-array parameter"
+    },
+    {
+      "line": 10,
+      "reason": "IMPLICIT requires a CLASS constructor NEW with one BYVAL non-array parameter"
+    },
+    {
+      "line": 14,
+      "reason": "IMPLICIT requires a CLASS constructor NEW with one BYVAL non-array parameter"
+    },
+    {
+      "line": 18,
+      "reason": "IMPLICIT requires a CLASS constructor NEW with one BYVAL non-array parameter"
+    }
+  ]
+}
diff --git a/tests/iii/implicit-declaration-errors/program.cps b/tests/iii/implicit-declaration-errors/program.cps
new file mode 100644
index 0000000..31cd23c
--- /dev/null
+++ b/tests/iii/implicit-declaration-errors/program.cps
@@ -0,0 +1,21 @@
+CLASS Invalid
+    IMPLICIT PROCEDURE NEW()
+    ENDPROCEDURE
+ENDCLASS
+CLASS RefInvalid
+    IMPLICIT PROCEDURE NEW(BYREF Value : INTEGER)
+    ENDPROCEDURE
+ENDCLASS
+CLASS ArrayInvalid
+    IMPLICIT PROCEDURE NEW(Value : ARRAY OF INTEGER)
+    ENDPROCEDURE
+ENDCLASS
+CLASS MethodInvalid
+    IMPLICIT PROCEDURE Convert(Value : INTEGER)
+    ENDPROCEDURE
+ENDCLASS
+CLASS PairInvalid
+    IMPLICIT PROCEDURE NEW(A : INTEGER, B : INTEGER)
+    ENDPROCEDURE
+ENDCLASS
+OUTPUT 1