Implement frontend layer to simplify cli commands.

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

@@ -10,5 +10,6 @@ sealed class Node {
   abstract val type: NodeType
   open fun <T> visitChildren(visitor: NodeVisitor<T>): List<T> = emptyList()
 
-  override fun toString(): String = let { node -> buildString { Printer(this).visit(node) } }
+  override fun toString(): String =
+    let { node -> buildString { Printer(this).visit(node) } }
 }

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

@@ -4,13 +4,9 @@ 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.frontend.FileFrontend
-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") {
@@ -23,9 +19,7 @@ class AstCommand : CliktCommand(help = "Print AST", name = "ast") {
   }
 
   override fun run() {
-    val content = path.readText()
+    val frontend = FileFrontend(path)
-    val tokenStream = PorkTokenizer(StringCharSource(content)).tokenize()
+    println(json.encodeToString(Node.serializer(), frontend.parse()))
-    val program = PorkParser(TokenStreamSource(tokenStream)).readProgram()
-    println(json.encodeToString(Node.serializer(), program))
   }
 }

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

@@ -4,20 +4,13 @@ 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.compiler.KotlinCompiler
-import gay.pizza.pork.parse.PorkParser
+import gay.pizza.pork.frontend.FileFrontend
-import gay.pizza.pork.parse.PorkTokenizer
-import gay.pizza.pork.parse.StringCharSource
-import gay.pizza.pork.parse.TokenStreamSource
-import kotlin.io.path.readText
 
 class GenerateKotlinCommand : CliktCommand(help = "Generate Kotlin Code", name = "generate-kotlin") {
   val path by argument("file").path(mustExist = true, canBeDir = false)
 
   override fun run() {
-    val content = path.readText()
+    val frontend = FileFrontend(path)
-    val tokenStream = PorkTokenizer(StringCharSource(content)).tokenize()
+    println(frontend.visit(KotlinCompiler()))
-    val program = PorkParser(TokenStreamSource(tokenStream)).readProgram()
-    val compiler = KotlinCompiler()
-    println(compiler.visit(program))
   }
 }

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

@@ -3,19 +3,14 @@ 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.frontend.FileFrontend
 import gay.pizza.pork.parse.AnsiHighlightScheme
-import gay.pizza.pork.parse.Highlighter
-import gay.pizza.pork.parse.PorkTokenizer
-import gay.pizza.pork.parse.StringCharSource
-import kotlin.io.path.readText
 
 class HighlightCommand : CliktCommand(help = "Syntax Highlighter", name = "highlight") {
   val path by argument("file").path(mustExist = true, canBeDir = false)
 
   override fun run() {
-    val content = path.readText()
+    val frontend = FileFrontend(path)
-    val tokenStream = PorkTokenizer(StringCharSource(content)).tokenize()
+    print(frontend.highlight(AnsiHighlightScheme()).joinToString(""))
-    val highlighter = Highlighter(AnsiHighlightScheme())
-    print(highlighter.highlight(tokenStream).joinToString(""))
   }
 }

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

@@ -3,20 +3,13 @@ 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.Printer
+import gay.pizza.pork.frontend.FileFrontend
-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 kotlin.io.path.readText
 
 class ReprintCommand : CliktCommand(help = "Reprint Parsed Program", name = "reprint") {
   val path by argument("file").path(mustExist = true, canBeDir = false)
 
   override fun run() {
-    val content = path.readText()
+    val frontend = FileFrontend(path)
-    val tokenStream = PorkTokenizer(StringCharSource(content)).tokenize()
+    print(frontend.reprint())
-    val program = PorkParser(TokenStreamSource(tokenStream)).readProgram()
-    print(buildString { Printer(this).visit(program) })
   }
 }

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

@@ -4,29 +4,20 @@ 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.eval.CallableFunction
-import gay.pizza.pork.eval.PorkEvaluator
 import gay.pizza.pork.eval.Scope
-import gay.pizza.pork.parse.PorkParser
+import gay.pizza.pork.frontend.FileFrontend
-import gay.pizza.pork.parse.PorkTokenizer
-import gay.pizza.pork.parse.StringCharSource
-import gay.pizza.pork.parse.TokenStreamSource
-import kotlin.io.path.readText
 
 class RunCommand : CliktCommand(help = "Run Program", name = "run") {
   val path by argument("file").path(mustExist = true, canBeDir = false)
 
   override fun run() {
-    val content = path.readText()
+    val frontend = FileFrontend(path)
-    val tokenStream = PorkTokenizer(StringCharSource(content)).tokenize()
-    val program = PorkParser(TokenStreamSource(tokenStream)).readProgram()
-
     val scope = Scope()
     scope.define("println", CallableFunction { arguments ->
       for (argument in arguments.values) {
         println(argument)
       }
     })
-    val evaluator = PorkEvaluator(scope)
+    frontend.evaluate(scope)
-    evaluator.visit(program)
   }
 }

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

@@ -3,16 +3,14 @@ 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.parse.PorkTokenizer
+import gay.pizza.pork.frontend.FileFrontend
-import gay.pizza.pork.parse.StringCharSource
-import kotlin.io.path.readText
 
 class TokenizeCommand : CliktCommand(help = "Tokenize Program", name = "tokenize") {
   val path by argument("file").path(mustExist = true, canBeDir = false)
 
   override fun run() {
-    val content = path.readText()
+    val frontend = FileFrontend(path)
-    val tokenStream = PorkTokenizer(StringCharSource(content)).tokenize()
+    val tokenStream = frontend.tokenize()
     for (token in tokenStream.tokens) {
       println("${token.start} ${token.type.name} '${sanitize(token.text)}'")
     }

src/main/kotlin/gay/pizza/pork/eval/Evaluator.kt

@@ -3,7 +3,7 @@ package gay.pizza.pork.eval
 import gay.pizza.pork.ast.*
 import gay.pizza.pork.ast.nodes.*
 
-class PorkEvaluator(root: Scope) : NodeVisitor<Any> {
+class Evaluator(root: Scope) : NodeVisitor<Any> {
   private var currentScope: Scope = root
 
   override fun visitDefine(node: Define): Any {

src/main/kotlin/gay/pizza/pork/frontend/FileFrontend.kt

@@ -0,0 +1,11 @@
+package gay.pizza.pork.frontend
+
+import gay.pizza.pork.ast.NodeVisitor
+import gay.pizza.pork.parse.CharSource
+import gay.pizza.pork.parse.StringCharSource
+import java.nio.file.Path
+import kotlin.io.path.readText
+
+class FileFrontend(val path: Path) : Frontend() {
+  override fun createCharSource(): CharSource = StringCharSource(path.readText())
+}

src/main/kotlin/gay/pizza/pork/frontend/Frontend.kt

@@ -0,0 +1,28 @@
+package gay.pizza.pork.frontend
+
+import gay.pizza.pork.ast.NodeVisitor
+import gay.pizza.pork.ast.Printer
+import gay.pizza.pork.ast.nodes.Program
+import gay.pizza.pork.eval.Evaluator
+import gay.pizza.pork.eval.Scope
+import gay.pizza.pork.parse.*
+
+abstract class Frontend {
+  abstract fun createCharSource(): CharSource
+
+  fun tokenize(): TokenStream =
+    Tokenizer(createCharSource()).tokenize()
+
+  fun parse(): Program =
+    Parser(TokenStreamSource(tokenize())).readProgram()
+
+  fun highlight(scheme: HighlightScheme): List<Highlight> =
+    Highlighter(scheme).highlight(tokenize())
+
+  fun evaluate(scope: Scope = Scope()): Any =
+    visit(Evaluator(scope))
+
+  fun reprint(): String = buildString { visit(Printer(this)) }
+
+  fun <T> visit(visitor: NodeVisitor<T>): T = visitor.visit(parse())
+}

src/main/kotlin/gay/pizza/pork/parse/Parser.kt

@@ -2,7 +2,7 @@ package gay.pizza.pork.parse
 
 import gay.pizza.pork.ast.nodes.*
 
-class PorkParser(source: PeekableSource<Token>) {
+class Parser(source: PeekableSource<Token>) {
   private val unsanitizedSource = source
 
   private fun readIntLiteral(): IntLiteral {

src/main/kotlin/gay/pizza/pork/parse/Tokenizer.kt

@@ -1,6 +1,6 @@
 package gay.pizza.pork.parse
 
-class PorkTokenizer(val source: CharSource) {
+class Tokenizer(val source: CharSource) {
   private var tokenStart: Int = 0
 
   private fun isSymbol(c: Char): Boolean =