Implement AST serialization.

build.gradle.kts

@@ -24,6 +24,7 @@ dependencies {
   implementation("org.jetbrains.kotlin:kotlin-bom")
   implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
   implementation("com.github.ajalt.clikt:clikt:4.2.0")
+  implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.6.0-RC")
 }
 
 tasks.withType<KotlinCompile> {

src/main/kotlin/gay/pizza/pork/ast/nodes/BooleanLiteral.kt

@@ -1,7 +1,11 @@
 package gay.pizza.pork.ast.nodes
 
 import gay.pizza.pork.ast.NodeType
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
+@Serializable
+@SerialName("booleanLiteral")
 class BooleanLiteral(val value: Boolean) : Expression() {
   override val type: NodeType = NodeType.BooleanLiteral
 

src/main/kotlin/gay/pizza/pork/ast/nodes/Define.kt

@@ -2,7 +2,11 @@ package gay.pizza.pork.ast.nodes
 
 import gay.pizza.pork.ast.NodeType
 import gay.pizza.pork.ast.NodeVisitor
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
+@Serializable
+@SerialName("define")
 class Define(val symbol: Symbol, val value: Expression) : Expression() {
   override val type: NodeType = NodeType.Define
 

src/main/kotlin/gay/pizza/pork/ast/nodes/Expression.kt

@@ -1,3 +1,6 @@
 package gay.pizza.pork.ast.nodes
 
-abstract class Expression : Node()
+import kotlinx.serialization.Serializable
+
+@Serializable
+sealed class Expression : Node()

src/main/kotlin/gay/pizza/pork/ast/nodes/FunctionCall.kt

@@ -2,7 +2,11 @@ package gay.pizza.pork.ast.nodes
 
 import gay.pizza.pork.ast.NodeType
 import gay.pizza.pork.ast.NodeVisitor
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
+@Serializable
+@SerialName("functionCall")
 class FunctionCall(val symbol: Symbol, val arguments: List<Expression>) : Expression() {
   override val type: NodeType = NodeType.FunctionCall
 
@@ -13,4 +17,11 @@ class FunctionCall(val symbol: Symbol, val arguments: List<Expression>) : Expres
     if (other !is FunctionCall) return false
     return other.symbol == symbol && other.arguments == arguments
   }
+
+  override fun hashCode(): Int {
+    var result = symbol.hashCode()
+    result = 31 * result + arguments.hashCode()
+    result = 31 * result + type.hashCode()
+    return result
+  }
 }

src/main/kotlin/gay/pizza/pork/ast/nodes/If.kt

@@ -2,7 +2,11 @@ package gay.pizza.pork.ast.nodes
 
 import gay.pizza.pork.ast.NodeType
 import gay.pizza.pork.ast.NodeVisitor
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
+@Serializable
+@SerialName("if")
 class If(
   val condition: Expression,
   val thenExpression: Expression,

src/main/kotlin/gay/pizza/pork/ast/nodes/InfixOperation.kt

@@ -2,7 +2,11 @@ package gay.pizza.pork.ast.nodes
 
 import gay.pizza.pork.ast.NodeType
 import gay.pizza.pork.ast.NodeVisitor
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
+@Serializable
+@SerialName("infixOperation")
 class InfixOperation(
   val left: Expression,
   val op: InfixOperator,

src/main/kotlin/gay/pizza/pork/ast/nodes/InfixOperator.kt

@@ -1,5 +1,10 @@
 package gay.pizza.pork.ast.nodes
 
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+@SerialName("infixOperator")
 enum class InfixOperator(val token: String) {
   Plus("+"),
   Minus("-"),

src/main/kotlin/gay/pizza/pork/ast/nodes/IntLiteral.kt

@@ -1,7 +1,11 @@
 package gay.pizza.pork.ast.nodes
 
 import gay.pizza.pork.ast.NodeType
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
+@Serializable
+@SerialName("intLiteral")
 class IntLiteral(val value: Int) : Expression() {
   override val type: NodeType = NodeType.IntLiteral
 

src/main/kotlin/gay/pizza/pork/ast/nodes/Lambda.kt

@@ -2,7 +2,11 @@ package gay.pizza.pork.ast.nodes
 
 import gay.pizza.pork.ast.NodeType
 import gay.pizza.pork.ast.NodeVisitor
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
+@Serializable
+@SerialName("lambda")
 class Lambda(val arguments: List<Symbol>, val expressions: List<Expression>) : Expression() {
   override val type: NodeType = NodeType.Lambda
 

src/main/kotlin/gay/pizza/pork/ast/nodes/ListLiteral.kt

@@ -2,7 +2,11 @@ package gay.pizza.pork.ast.nodes
 
 import gay.pizza.pork.ast.NodeType
 import gay.pizza.pork.ast.NodeVisitor
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
+@Serializable
+@SerialName("listLiteral")
 class ListLiteral(val items: List<Expression>) : Expression() {
   override val type: NodeType = NodeType.ListLiteral
 

src/main/kotlin/gay/pizza/pork/ast/nodes/Node.kt

@@ -3,8 +3,10 @@ package gay.pizza.pork.ast.nodes
 import gay.pizza.pork.ast.NodeType
 import gay.pizza.pork.ast.Printer
 import gay.pizza.pork.ast.NodeVisitor
+import kotlinx.serialization.Serializable
 
-abstract class Node {
+@Serializable
+sealed class Node {
   abstract val type: NodeType
   open fun <T> visitChildren(visitor: NodeVisitor<T>): List<T> = emptyList()
 

src/main/kotlin/gay/pizza/pork/ast/nodes/Parentheses.kt

@@ -2,7 +2,11 @@ package gay.pizza.pork.ast.nodes
 
 import gay.pizza.pork.ast.NodeType
 import gay.pizza.pork.ast.NodeVisitor
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
+@Serializable
+@SerialName("parentheses")
 class Parentheses(val expression: Expression) : Expression() {
   override val type: NodeType = NodeType.Parentheses
 

src/main/kotlin/gay/pizza/pork/ast/nodes/PrefixOperation.kt

@@ -2,7 +2,11 @@ package gay.pizza.pork.ast.nodes
 
 import gay.pizza.pork.ast.NodeType
 import gay.pizza.pork.ast.NodeVisitor
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
+@Serializable
+@SerialName("prefixOperation")
 class PrefixOperation(val op: PrefixOperator, val expression: Expression) : Expression() {
   override val type: NodeType = NodeType.PrefixOperation
 

src/main/kotlin/gay/pizza/pork/ast/nodes/PrefixOperator.kt

@@ -1,5 +1,10 @@
 package gay.pizza.pork.ast.nodes
 
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+@SerialName("prefixOperator")
 enum class PrefixOperator(val token: String) {
   Negate("!")
 }

src/main/kotlin/gay/pizza/pork/ast/nodes/Program.kt

@@ -2,7 +2,11 @@ package gay.pizza.pork.ast.nodes
 
 import gay.pizza.pork.ast.NodeType
 import gay.pizza.pork.ast.NodeVisitor
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
+@Serializable
+@SerialName("program")
 class Program(val expressions: List<Expression>) : Node() {
   override val type: NodeType = NodeType.Program
 

src/main/kotlin/gay/pizza/pork/ast/nodes/Symbol.kt

@@ -1,7 +1,11 @@
 package gay.pizza.pork.ast.nodes
 
 import gay.pizza.pork.ast.NodeType
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
+@Serializable
+@SerialName("symbol")
 class Symbol(val id: String) : Node() {
   override val type: NodeType = NodeType.Symbol
 

src/main/kotlin/gay/pizza/pork/ast/nodes/SymbolReference.kt

@@ -2,7 +2,11 @@ package gay.pizza.pork.ast.nodes
 
 import gay.pizza.pork.ast.NodeType
 import gay.pizza.pork.ast.NodeVisitor
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
+@Serializable
+@SerialName("symbolReference")
 class SymbolReference(val symbol: Symbol) : Expression() {
   override val type: NodeType = NodeType.SymbolReference
 

src/main/kotlin/gay/pizza/pork/cli/AstCommand.kt

@@ -0,0 +1,31 @@
+package gay.pizza.pork.cli
+
+import com.github.ajalt.clikt.core.CliktCommand
+import com.github.ajalt.clikt.parameters.arguments.argument
+import com.github.ajalt.clikt.parameters.types.path
+import gay.pizza.pork.ast.nodes.Node
+import gay.pizza.pork.parse.PorkParser
+import gay.pizza.pork.parse.PorkTokenizer
+import gay.pizza.pork.parse.StringCharSource
+import gay.pizza.pork.parse.TokenStreamSource
+import kotlinx.serialization.ExperimentalSerializationApi
+import kotlinx.serialization.json.Json
+import kotlin.io.path.readText
+
+@OptIn(ExperimentalSerializationApi::class)
+class AstCommand : CliktCommand(help = "Print AST", name = "ast") {
+  val path by argument("file").path(mustExist = true, canBeDir = false)
+
+  private val json = Json {
+    prettyPrint = true
+    prettyPrintIndent = "  "
+    classDiscriminator = "\$"
+  }
+
+  override fun run() {
+    val content = path.readText()
+    val tokenStream = PorkTokenizer(StringCharSource(content)).tokenize()
+    val program = PorkParser(TokenStreamSource(tokenStream)).readProgram()
+    println(json.encodeToString(Node.serializer(), program))
+  }
+}

src/main/kotlin/gay/pizza/pork/cli/RootCommand.kt

@@ -13,6 +13,7 @@ class RootCommand : CliktCommand(
       HighlightCommand(),
       TokenizeCommand(),
       ReprintCommand(),
+      AstCommand(),
       GenerateKotlinCommand()
     )
   }