test(overload): add randomized differential coverage

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

7 files changed, 118 insertions, 0 deletions

diff --git a/tests/ii/overload-functions/arrays.cps b/tests/ii/overload-functions/arrays.cps
new file mode 100644
index 0000000..47ff46c
--- /dev/null
+++ b/tests/ii/overload-functions/arrays.cps
@@ -0,0 +1,21 @@
+OVERLOAD FUNCTION Score(Values : ARRAY OF INTEGER, First : INTEGER, Size : INTEGER) RETURNS INTEGER
+    DECLARE I : INTEGER
+    DECLARE Total : INTEGER
+    Total <- 0
+    FOR I <- First TO First + Size - 1
+        Total <- Total + Values[I]
+    NEXT I
+    RETURN Total
+ENDFUNCTION
+OVERLOAD FUNCTION Score(Values : ARRAY OF REAL, First : INTEGER, Size : INTEGER) RETURNS BOOLEAN
+    DECLARE I : INTEGER
+    DECLARE Total : REAL
+    Total <- 0.0
+    FOR I <- First TO First + Size - 1
+        Total <- Total + Values[I]
+    NEXT I
+    RETURN Total > 0.0
+ENDFUNCTION
+OVERLOAD FUNCTION Score(Values : ARRAY[1:2,1:2] OF INTEGER, First : INTEGER, Size : INTEGER) RETURNS INTEGER
+    RETURN Values[1,1] + 2 * Values[1,2] + 3 * Values[2,1] + 4 * Values[2,2]
+ENDFUNCTION
diff --git a/tests/ii/overload-functions/case.json b/tests/ii/overload-functions/case.json
new file mode 100644
index 0000000..073cfee
--- /dev/null
+++ b/tests/ii/overload-functions/case.json
@@ -0,0 +1,3 @@
+{
+  "sources": ["program.cps", "scalar.cps", "arrays.cps"]
+}
diff --git a/tests/ii/overload-functions/generate.pl b/tests/ii/overload-functions/generate.pl
new file mode 100644
index 0000000..33ca9f3
--- /dev/null
+++ b/tests/ii/overload-functions/generate.pl
@@ -0,0 +1,20 @@
+use strict;
+use warnings;
+use FindBin;
+use lib "$FindBin::Bin/..";
+use Random;
+my ($seed, $count) = @ARGV;
+my $rng = Random->new($seed, "overload-functions");
+my @edges = (
+    '0 0 1 0 x',
+    '-1000 1000 8 -8 boundary',
+    '1000 -1000 8 8 z',
+    '-7 2 8 -3 cancellation',
+    '1 -2 2 0 pair',
+    '-1 2 2 -1 positive',
+);
+$rng->emit($count, \@edges, sub {
+    return join ' ', $rng->integer(-1000,1000), $rng->integer(-1000,1000),
+                    $rng->integer(1,8), $rng->integer(-8,8),
+                    'x' x $rng->integer(1,24);
+});
diff --git a/tests/ii/overload-functions/notes.md b/tests/ii/overload-functions/notes.md
new file mode 100644
index 0000000..54b3f5d
--- /dev/null
+++ b/tests/ii/overload-functions/notes.md
@@ -0,0 +1,7 @@
+# overload-functions
+
+OVERLOAD is a project extension. The scalar and array overloads of Score are defined in separate imported files. Each input record exercises INTEGER, REAL and STRING argument types; different argument counts; FUNCTION and PROCEDURE sharing a name; BYREF scalar mutation; array element types and ranks; case-insensitive calls; and nested calls whose static result type selects the outer overload.
+
+Inputs are A, B, Size, Lower and a nonempty ASCII string. Integer array elements form the progression A + k*B for k from 0 to Size-1. REAL elements are those exact integers divided by eight. The independent C++ oracle uses the closed-form progression sum Size*A + B*Size*(Size-1)/2, its sign, and the simplified weighted matrix sum 8*A+B. The nested scalar result is 9*A+4, and the BYREF procedure changes only its destination to A+B*Size.
+
+Each record emits one colon-separated line. A and B stay within [-1000,1000], Size within [1,8], and Lower within [-8,8]; all arithmetic is safely bounded. Binary fractions are exactly representable, and REAL results are observed through BOOLEAN output. Fixed records cover zero, range endpoints, changing array bounds, positive/negative totals and exact cancellation. The SHA-256 generator adds the requested random count.
diff --git a/tests/ii/overload-functions/program.cps b/tests/ii/overload-functions/program.cps
new file mode 100644
index 0000000..ea94a93
--- /dev/null
+++ b/tests/ii/overload-functions/program.cps
@@ -0,0 +1,33 @@
+INCLUDE "scalar.cps"
+INCLUDE "arrays.cps"
+DECLARE Count : INTEGER
+DECLARE Row : INTEGER
+DECLARE A : INTEGER
+DECLARE B : INTEGER
+DECLARE Size : INTEGER
+DECLARE Lower : INTEGER
+DECLARE Text : STRING
+DECLARE I : INTEGER
+DECLARE Changed : INTEGER
+INPUT Count
+FOR Row <- 1 TO Count
+    INPUT A
+    INPUT B
+    INPUT Size
+    INPUT Lower
+    INPUT Text
+    DECLARE Integers : ARRAY[Lower:Lower+Size-1] OF INTEGER
+    DECLARE Reals : ARRAY[Lower:Lower+Size-1] OF REAL
+    DECLARE Matrix : ARRAY[1:2,1:2] OF INTEGER
+    FOR I <- Lower TO Lower + Size - 1
+        Integers[I] <- A + (I - Lower) * B
+        Reals[I] <- (A + (I - Lower) * B) / 8
+    NEXT I
+    Matrix[1,1] <- A
+    Matrix[1,2] <- B
+    Matrix[2,1] <- A + B
+    Matrix[2,2] <- A - B
+    Changed <- A
+    CALL sCoRe(Changed, B, Size)
+    OUTPUT Score(A), ":", Score(A / 8), ":", Score(Text), ":", Score(A, B), ":", Score(Integers, Lower, Size), ":", Score(Reals, Lower, Size), ":", Score(Matrix, Lower, Size), ":", Score(Score(A)), ":", Changed, ":", A
+NEXT Row
diff --git a/tests/ii/overload-functions/reference.cc b/tests/ii/overload-functions/reference.cc
new file mode 100644
index 0000000..2b4b03f
--- /dev/null
+++ b/tests/ii/overload-functions/reference.cc
@@ -0,0 +1,19 @@
+#include <cstdint>
+#include <iostream>
+#include <string>
+
+int main() {
+    int count;
+    if (!(std::cin >> count)) return 1;
+    for (int row = 0; row < count; ++row) {
+        std::int64_t a, b, size, lower;
+        std::string text;
+        if (!(std::cin >> a >> b >> size >> lower >> text)) return 1;
+        // Closed forms are independent of the pseudocode's loops and dispatch.
+        const auto sum = size * a + b * size * (size - 1) / 2;
+        std::cout << 3 * a + 1 << ':' << (a < 0 ? "TRUE" : "FALSE") << ':'
+                  << text.size() + 100 << ':' << 17 * a + b << ':' << sum << ':'
+                  << (sum > 0 ? "TRUE" : "FALSE") << ':' << 8 * a + b << ':'
+                  << 9 * a + 4 << ':' << a + b * size << ':' << a << '\n';
+    }
+}
diff --git a/tests/ii/overload-functions/scalar.cps b/tests/ii/overload-functions/scalar.cps
new file mode 100644
index 0000000..6953662
--- /dev/null
+++ b/tests/ii/overload-functions/scalar.cps
@@ -0,0 +1,15 @@
+OVERLOAD FUNCTION Score(X : INTEGER) RETURNS INTEGER
+    RETURN 3 * X + 1
+ENDFUNCTION
+OVERLOAD FUNCTION Score(X : REAL) RETURNS BOOLEAN
+    RETURN X < 0.0
+ENDFUNCTION
+OVERLOAD FUNCTION Score(Text : STRING) RETURNS INTEGER
+    RETURN LENGTH(Text) + 100
+ENDFUNCTION
+OVERLOAD FUNCTION Score(X : INTEGER, Y : INTEGER) RETURNS INTEGER
+    RETURN 17 * X + Y
+ENDFUNCTION
+OVERLOAD PROCEDURE Score(BYREF Value : INTEGER, BYVAL Delta : INTEGER, Repetitions : INTEGER)
+    Value <- Value + Delta * Repetitions
+ENDPROCEDURE