feat: add switchOp and caseOp #22

Author: phodal

chapi-domain/src/main/kotlin/chapi/domain/expr/Expression.kt

@@ -68,6 +68,22 @@ sealed class Expression {
         override fun toString() = "[${args.joinToString(", ")}]"
     }
 
+    class SwitchCases(val lhs: ExpressionNode, val cases: Array<CaseOp>, val defaultBlock: ExpressionNode?) : ExpressionNode {
+        override fun toString(): String {
+            val casesStr = cases.joinToString("\n") { "case ${it.condition}: ${it.thenBlock}" }
+            val defaultStr = if (defaultBlock != null) {
+                "default: $defaultBlock"
+            } else {
+                ""
+            }
+            return "switch ($lhs) {\n$casesStr\n$defaultStr\n}"
+        }
+    }
+    
+    class CaseOp(val condition: ExpressionNode, val thenBlock: ExpressionNode) : ExpressionNode {
+        override fun toString() = "$condition -> $thenBlock"
+    }
+    
     class Value(val value: Any) : ExpressionNode {
         override fun toString() = value.toString()
     }

chapi-domain/src/test/kotlin/chapi/domain/expr/ExpressionTest.kt

@@ -135,4 +135,23 @@ class ExpressionTest {
             ).toString(), "a = 1"
         )
     }
+
+    @Test
+    fun switchCase() {
+        assertEquals(Expression.SwitchCases(
+                lhs = Expression.Variable("a"),
+                cases = arrayOf(
+                    Expression.CaseOp(
+                        condition = Expression.IntValue(1),
+                        thenBlock = Expression.IntValue(2)
+                    ),
+                    Expression.CaseOp(
+                        condition = Expression.IntValue(2),
+                        thenBlock = Expression.IntValue(3)
+                    )
+                ),
+                defaultBlock = Expression.IntValue(4)
+            ).toString(), "switch (a) { case 1: 2; case 2: 3; default: 4; }"
+        )
+    }
 }