From 34755a31a4299279a5b03b407cd0d8ba802c3331 Mon Sep 17 00:00:00 2001
From: Phodal Huang <h@phodal.com>
Date: Wed, 9 Nov 2022 12:14:15 +0800
Subject: [PATCH] feat: init basic pratter for #22

---
 .../kotlin/chapi/domain/expr/Expression.kt    | 28 --------
 .../kotlin/chapi/domain/expr/TokenTree.kt     | 67 +++++++++++++++++++
 .../chapi/domain/expr/ExpressionTest.kt       | 10 +++
 3 files changed, 77 insertions(+), 28 deletions(-)
 delete mode 100644 chapi-domain/src/main/kotlin/chapi/domain/expr/Expression.kt
 create mode 100644 chapi-domain/src/main/kotlin/chapi/domain/expr/TokenTree.kt
 create mode 100644 chapi-domain/src/test/kotlin/chapi/domain/expr/ExpressionTest.kt

diff --git a/chapi-domain/src/main/kotlin/chapi/domain/expr/Expression.kt b/chapi-domain/src/main/kotlin/chapi/domain/expr/Expression.kt
deleted file mode 100644
index c6535764..00000000
--- a/chapi-domain/src/main/kotlin/chapi/domain/expr/Expression.kt
+++ /dev/null
@@ -1,28 +0,0 @@
-package chapi.domain.expr
-
-import java.util.function.BinaryOperator
-import java.util.function.IntBinaryOperator
-
-class Expression(
-    var Type: ExpressionType,
-    var Value: String = "",
-    var Children: Array<Expression> = arrayOf()
-)
-
-enum class ExpressionType {
-    Primary,
-    Infix,
-    Prefix,
-    Postfix,
-}
-
-enum class Arithmetics : BinaryOperator<Int>, IntBinaryOperator {
-    PLUS {
-        override fun apply(t: Int, u: Int): Int {
-            return t + u
-        }
-    }
-    ;
-
-    override fun applyAsInt(t: Int, u: Int) = apply(t, u)
-}
diff --git a/chapi-domain/src/main/kotlin/chapi/domain/expr/TokenTree.kt b/chapi-domain/src/main/kotlin/chapi/domain/expr/TokenTree.kt
new file mode 100644
index 00000000..d171f10a
--- /dev/null
+++ b/chapi-domain/src/main/kotlin/chapi/domain/expr/TokenTree.kt
@@ -0,0 +1,67 @@
+package chapi.domain.expr
+
+import java.util.function.BinaryOperator
+import java.util.function.IntBinaryOperator
+
+// todo: mapping to pratt parser ?
+// mini sample <https://github.com/segeljakt/pratt>
+//
+// enum class TokenTree {
+//     Primary,
+//     Prefix,
+//     Infix,
+//     Postfix;
+// }
+sealed class Expression {
+    class BinOp(lhs: Expression, op: BinOpKind, rhs: Expression) : ExpressionNode
+    class UnOp(lhs: Expression, op: UnOpKind) : ExpressionNode
+    class Int(val value: Int?) : ExpressionNode
+}
+
+sealed class BinOpKind {
+    object Add : BinOpKind() // +
+    object Sub : BinOpKind() // -
+    object Mul : BinOpKind() // *
+    object Div : BinOpKind() // /
+    object Pow : BinOpKind() // ^
+    object Eq : BinOpKind() // =
+}
+
+sealed class UnOpKind {
+    object Not : UnOpKind() // !
+    object Neg : UnOpKind() // -
+    object Try : UnOpKind() // ?
+}
+
+interface ExpressionType {
+    val name: String
+}
+
+interface ExpressionNode {
+    val childrens: Array<ExpressionNode> get() = emptyArray()
+    val expressionTypes: Array<ExpressionType> get() = emptyArray()
+
+    fun getPriority(): Int = 0
+
+    fun addChildren(child: Operator) {
+        childrens.plus(child)
+    }
+
+    fun addExpressionType(type: ExpressionType) {
+        expressionTypes.plus(type)
+    }
+}
+
+
+interface Operator : ExpressionNode
+
+enum class Arithmetics : BinaryOperator<Int>, IntBinaryOperator {
+    PLUS {
+        override fun apply(t: Int, u: Int): Int {
+            return t + u
+        }
+    }
+    ;
+
+    override fun applyAsInt(t: Int, u: Int) = apply(t, u)
+}
diff --git a/chapi-domain/src/test/kotlin/chapi/domain/expr/ExpressionTest.kt b/chapi-domain/src/test/kotlin/chapi/domain/expr/ExpressionTest.kt
new file mode 100644
index 00000000..4b7080d7
--- /dev/null
+++ b/chapi-domain/src/test/kotlin/chapi/domain/expr/ExpressionTest.kt
@@ -0,0 +1,10 @@
+package chapi.domain.expr
+
+import org.junit.jupiter.api.Test
+
+class ExpressionTest {
+    @Test
+    fun shouldAddChildren() {
+
+    }
+}