Functor

tests/prolog/builtins/AnalysingAndConstructionOperatorsTests.kt

@@ -0,0 +1,91 @@
+package prolog.builtins
+
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertInstanceOf
+import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.Test
+import prolog.ast.arithmetic.Integer
+import prolog.ast.terms.AnonymousVariable
+import prolog.ast.terms.Atom
+import prolog.ast.terms.Structure
+import prolog.ast.terms.Variable
+
+class AnalysingAndConstructionOperatorsTests {
+    @Test
+    fun `functor(foo, foo, 0)`() {
+        val functor = Functor(Atom("foo"), Atom("foo"), Integer(0))
+
+        val result = functor.satisfy(emptyMap()).toList()
+
+        assertEquals(1, result.size, "Expected 1 result")
+        assertTrue(result[0].isSuccess, "Expected success")
+        assertTrue(result[0].getOrNull()!!.isEmpty(), "Expected empty substitutions")
+    }
+
+    @Test
+    fun `functor(foo(X), foo, Y)`() {
+        val functor = Functor(
+            Structure(Atom("foo"), listOf(Variable("X"))),
+            Atom("foo"),
+            Variable("Y")
+        )
+
+        val result = functor.satisfy(emptyMap()).toList()
+
+        assertEquals(1, result.size, "Expected 1 result")
+        assertTrue(result[0].isSuccess, "Expected success")
+        val subs = result[0].getOrNull()!!
+        assertEquals(1, subs.size, "Expected 1 substitution")
+        assertEquals(Integer(1), subs[Variable("Y")])
+    }
+
+    @Test
+    fun `functor(foo, X, Y)`() {
+        val atom = Atom("foo")
+        val functor = Functor(atom, Variable("X"), Variable("Y"))
+
+        val result = functor.satisfy(emptyMap()).toList()
+
+        assertEquals(1, result.size, "Expected 1 result")
+        assertTrue(result[0].isSuccess, "Expected success")
+        val subs = result[0].getOrNull()!!
+        assertEquals(2, subs.size, "Expected 2 substitutions")
+        assertEquals(atom.functor.name, subs[Variable("X")])
+        assertEquals(atom.functor.arity, subs[Variable("Y")])
+    }
+
+    @Test
+    fun `functor(X, foo, 1)`() {
+        val functor = Functor(Variable("X"), Atom("foo"), Integer(1))
+
+        val result = functor.satisfy(emptyMap()).toList()
+
+        assertEquals(1, result.size, "Expected 1 result")
+        assertTrue(result[0].isSuccess, "Expected success")
+        val subs = result[0].getOrNull()!!
+        assertEquals(1, subs.size, "Expected 1 substitution")
+        assertInstanceOf(Structure::class.java, subs[Variable("X")])
+        val structure = subs[Variable("X")] as Structure
+        assertEquals(Atom("foo"), structure.name)
+        assertEquals(1, structure.arguments.size)
+        assertInstanceOf(AnonymousVariable::class.java, structure.arguments[0])
+    }
+
+    @Test
+    fun `functor(foo(a), foo, 0)`() {
+        val functor = Functor(Structure(Atom("foo"), listOf(Atom("a"))), Atom("foo"), Integer(0))
+
+        val result = functor.satisfy(emptyMap()).toList()
+
+        assertTrue(result.isEmpty(), "Expected no results")
+    }
+
+    @Test
+    fun `functor(foo(X), foo, 0)`() {
+        val functor = Functor(Structure(Atom("foo"), listOf(Variable("X"))), Atom("foo"), Integer(0))
+
+        val result = functor.satisfy(emptyMap()).toList()
+
+        assertTrue(result.isEmpty(), "Expected no results")
+    }
+}