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-rw-r--r--src/CoreBindings.kt109
-rw-r--r--src/LispAst.kt41
-rw-r--r--src/LispData.kt105
-rw-r--r--src/LispErrorReporter.kt15
-rw-r--r--src/LispExecutionContext.kt61
-rw-r--r--src/LispParser.kt116
-rw-r--r--src/LispParsingError.kt4
-rw-r--r--src/LispPosition.kt21
-rw-r--r--src/StackFrame.kt32
-rw-r--r--src/StringRacer.kt81
10 files changed, 585 insertions, 0 deletions
diff --git a/src/CoreBindings.kt b/src/CoreBindings.kt
new file mode 100644
index 0000000..9213917
--- /dev/null
+++ b/src/CoreBindings.kt
@@ -0,0 +1,109 @@
+package moe.nea.lisp
+
+object CoreBindings {
+ val nil = LispData.LispNil
+ val def = LispData.externalRawCall { context, callsite, stackFrame, args ->
+ if (args.size != 2) {
+ return@externalRawCall context.reportError("Function define expects exactly two arguments", callsite)
+ }
+ val (name, value) = args
+ if (name !is LispAst.Reference) {
+ return@externalRawCall context.reportError("Define expects a name as first argument", name)
+ }
+ if (name.label in stackFrame.variables) {
+ return@externalRawCall context.reportError("Cannot redefine value in local context", name)
+ }
+ return@externalRawCall stackFrame.setValueLocal(name.label, context.resolveValue(stackFrame, value))
+ }
+
+ val pure = LispData.externalCall { args, reportError ->
+ return@externalCall args.singleOrNull()?.let { value ->
+ LispData.externalCall { args, reportError ->
+ if (args.isNotEmpty())
+ reportError("Pure function does not expect arguments")
+ else
+ value
+ }
+ } ?: reportError("Function pure expects exactly one argument")
+ }
+
+ val lambda = LispData.externalRawCall { context, callsite, stackFrame, args ->
+ if (args.size != 2) {
+ return@externalRawCall context.reportError("Lambda needs exactly 2 arguments", callsite)
+ }
+ val (argumentNames, body) = args
+ if (argumentNames !is LispAst.Parenthesis) {
+ return@externalRawCall context.reportError("Lambda has invalid argument declaration", argumentNames)
+ }
+ val argumentNamesString = argumentNames.items.map {
+ val ref = it as? LispAst.Reference
+ if (ref == null) {
+ return@externalRawCall context.reportError("Lambda has invalid argument declaration", it)
+ }
+ ref.label
+ }
+ if (body !is LispAst.Parenthesis) {
+ return@externalRawCall context.reportError("Lambda has invalid body declaration", body)
+ }
+ LispData.createLambda(stackFrame, argumentNamesString, body)
+ }
+
+ val defun = LispData.externalRawCall { context, callSite, stackFrame, lispAsts ->
+ if (lispAsts.size != 3) {
+ return@externalRawCall context.reportError("Invalid function definition", callSite)
+ }
+ val (name, args, body) = lispAsts
+ if (name !is LispAst.Reference) {
+ return@externalRawCall context.reportError("Invalid function definition name", name)
+ }
+ if (name.label in stackFrame.variables) {
+ return@externalRawCall context.reportError("Cannot redefine function in local context", name)
+ }
+ if (args !is LispAst.Parenthesis) {
+ return@externalRawCall context.reportError("Invalid function definition arguments", args)
+ }
+ val argumentNames = args.items.map {
+ val ref = it as? LispAst.Reference
+ ?: return@externalRawCall context.reportError("Invalid function definition argument name", it)
+ ref.label
+ }
+ if (body !is LispAst.Parenthesis) {
+ return@externalRawCall context.reportError("Invalid function definition body", body)
+ }
+ return@externalRawCall stackFrame.setValueLocal(
+ name.label,
+ LispData.createLambda(stackFrame, argumentNames, body, name.label)
+ )
+ }
+ val seq = LispData.externalRawCall { context, callsite, stackFrame, args ->
+ var lastResult: LispData? = null
+ for (arg in args) {
+ lastResult = context.executeLisp(stackFrame, arg)
+ }
+ lastResult ?: context.reportError("Seq cannot be invoked with 0 argumens", callsite)
+ }
+ val debuglog = LispData.externalRawCall { context, callsite, stackFrame, args ->
+ println(args.joinToString(" ") { arg ->
+ when (val resolved = context.resolveValue(stackFrame, arg)) {
+ is LispData.Atom -> ":${resolved.label}"
+ is LispData.JavaExecutable -> "<native code>"
+ LispData.LispNil -> "nil"
+ is LispData.LispNumber -> resolved.number.toString()
+ is LispData.LispNode -> resolved.node.toSource()
+ is LispData.LispObject<*> -> resolved.data.toString()
+ is LispData.LispInterpretedCallable -> "<function ${resolved.name ?: ""} ${resolved.argNames} ${resolved.body.toSource()}>"
+ }
+ })
+ LispData.LispNil
+ }
+
+ fun offerAllTo(bindings: StackFrame) {
+ bindings.setValueLocal("nil", nil)
+ bindings.setValueLocal("def", def)
+ bindings.setValueLocal("pure", pure)
+ bindings.setValueLocal("lambda", lambda)
+ bindings.setValueLocal("defun", defun)
+ bindings.setValueLocal("seq", seq)
+ bindings.setValueLocal("debuglog", debuglog)
+ }
+} \ No newline at end of file
diff --git a/src/LispAst.kt b/src/LispAst.kt
new file mode 100644
index 0000000..79fee8a
--- /dev/null
+++ b/src/LispAst.kt
@@ -0,0 +1,41 @@
+package moe.nea.lisp
+
+sealed class LispAst : HasLispPosition {
+
+
+ abstract fun toSource(): String
+
+
+ data class Program(override val position: LispPosition, val nodes: List<LispNode>) : LispAst() {
+ override fun toSource(): String {
+ return nodes.joinToString("\n") {
+ it.toSource()
+ }
+ }
+ }
+
+ sealed class LispNode : LispAst()
+ data class Atom(override val position: LispPosition, val label: String) : LispNode() {
+ override fun toSource(): String {
+ return ":$label"
+ }
+ }
+
+ data class Reference(override val position: LispPosition, val label: String) : LispNode() {
+ override fun toSource(): String {
+ return label
+ }
+ }
+
+ data class Parenthesis(override val position: LispPosition, val items: List<LispNode>) : LispNode() {
+ override fun toSource(): String {
+ return items.joinToString(" ", "(", ")") { it.toSource() }
+ }
+ }
+
+ data class StringLiteral(override val position: LispPosition, val parsedString: String) : LispNode() {
+ override fun toSource(): String {
+ return "\"${parsedString.replace("\\", "\\\\").replace("\"", "\\\"")}\"" // TODO: better escaping
+ }
+ }
+}
diff --git a/src/LispData.kt b/src/LispData.kt
new file mode 100644
index 0000000..1f13ad3
--- /dev/null
+++ b/src/LispData.kt
@@ -0,0 +1,105 @@
+package moe.nea.lisp
+
+sealed class LispData {
+
+ fun <T : Any> lispCastObject(lClass: LispClass<T>): LispObject<T>? {
+ if (this !is LispObject<*>) return null
+ if (this.handler != lClass) return null
+ return this as LispObject<T>
+ }
+
+ object LispNil : LispData()
+ data class Atom(val label: String) : LispData()
+ data class LispNode(val node: LispAst.LispNode) : LispData()
+ data class LispNumber(val number: Double) : LispData()
+ data class LispObject<T : Any>(val data: T, val handler: LispClass<T>) : LispData()
+ sealed class LispExecutable() : LispData() {
+ abstract fun execute(
+ executionContext: LispExecutionContext,
+ callsite: LispAst.LispNode,
+ stackFrame: StackFrame,
+ args: List<LispAst.LispNode>
+ ): LispData
+ }
+
+
+ abstract class JavaExecutable : LispExecutable() {
+ }
+
+ data class LispInterpretedCallable(
+ val declarationStackFrame: StackFrame,
+ val argNames: List<String>,
+ val body: LispAst.Parenthesis,
+ val name: String?,
+ ) : LispExecutable() {
+ override fun execute(
+ executionContext: LispExecutionContext,
+ callsite: LispAst.LispNode,
+ stackFrame: StackFrame,
+ args: List<LispAst.LispNode>
+ ): LispData {
+ if (argNames.size != args.size) {
+ TODO("ERROR")
+ }
+ val invocationFrame = declarationStackFrame.fork()
+
+ for ((name, value) in argNames.zip(args)) {
+ invocationFrame.setValueLocal(name, executionContext.resolveValue(stackFrame, value))
+ }
+ return executionContext.executeLisp(invocationFrame, body)
+ }
+ }
+
+ interface LispClass<T : Any> {
+ fun access(obj: T, name: String): LispData
+ fun instantiate(obj: T) = LispObject(obj, this)
+ }
+
+ object LispStringClass : LispClass<String> {
+ override fun access(obj: String, name: String): LispData {
+ return LispNil
+ }
+ }
+
+ companion object {
+ fun string(value: String): LispObject<String> =
+ LispStringClass.instantiate(value)
+
+ fun externalRawCall(callable: (context: LispExecutionContext, callsite: LispAst.LispNode, stackFrame: StackFrame, args: List<LispAst.LispNode>) -> LispData): LispExecutable {
+ return object : JavaExecutable() {
+ override fun execute(
+ executionContext: LispExecutionContext,
+ callsite: LispAst.LispNode,
+ stackFrame: StackFrame,
+ args: List<LispAst.LispNode>
+ ): LispData {
+ return callable.invoke(executionContext, callsite, stackFrame, args)
+ }
+ }
+ }
+
+ fun externalCall(callable: (args: List<LispData>, reportError: (String) -> LispData) -> LispData): LispExecutable {
+ return object : JavaExecutable() {
+ override fun execute(
+ executionContext: LispExecutionContext,
+ callsite: LispAst.LispNode,
+ stackFrame: StackFrame,
+ args: List<LispAst.LispNode>
+ ): LispData {
+ val mappedArgs = args.map { executionContext.resolveValue(stackFrame, it) }
+ return callable.invoke(mappedArgs) { executionContext.reportError(it, callsite) }
+ }
+ }
+ }
+
+
+ fun createLambda(
+ declarationStackFrame: StackFrame,
+ args: List<String>,
+ body: LispAst.Parenthesis,
+ nameHint: String? = null,
+ ): LispExecutable {
+ return LispInterpretedCallable(declarationStackFrame, args, body, nameHint)
+ }
+ }
+}
diff --git a/src/LispErrorReporter.kt b/src/LispErrorReporter.kt
new file mode 100644
index 0000000..d9ad148
--- /dev/null
+++ b/src/LispErrorReporter.kt
@@ -0,0 +1,15 @@
+package moe.nea.lisp
+
+class LispErrorReporter {
+
+ data class LispError(val name: String, val position: LispPosition)
+
+
+ val errors = listOf<LispError>()
+
+ fun reportError(name: String, position: HasLispPosition) {
+ println("LISP ERROR: $name at ${position.position}")
+ }
+
+
+}
diff --git a/src/LispExecutionContext.kt b/src/LispExecutionContext.kt
new file mode 100644
index 0000000..f169ba9
--- /dev/null
+++ b/src/LispExecutionContext.kt
@@ -0,0 +1,61 @@
+package moe.nea.lisp
+
+class LispExecutionContext() {
+
+ private val errorReporter = LispErrorReporter()
+ private val rootStackFrame = StackFrame(null)
+
+
+ fun reportError(name: String, position: HasLispPosition): LispData.LispNil {
+ println("Error: $name ${position.position}")
+ return LispData.LispNil
+ }
+
+
+ fun genBindings(): StackFrame {
+ return StackFrame(rootStackFrame)
+ }
+
+ fun executeProgram(stackFrame: StackFrame, program: LispAst.Program) {
+ for (node in program.nodes) {
+ executeLisp(stackFrame, node)
+ }
+ }
+
+
+ fun executeLisp(stackFrame: StackFrame, node: LispAst.LispNode): LispData {
+ when (node) {
+ is LispAst.Parenthesis -> {
+ val first = node.items.firstOrNull()
+ ?: return reportError("Cannot execute empty parenthesis ()", node)
+
+ val rest = node.items.drop(1)
+ return when (val resolvedValue = resolveValue(stackFrame, first)) {
+ is LispData.Atom -> reportError("Cannot execute atom", node)
+ LispData.LispNil -> reportError("Cannot execute nil", node)
+ is LispData.LispNumber -> reportError("Cannot execute number", node)
+ is LispData.LispNode -> reportError("Cannot execute node", node)
+ is LispData.LispObject<*> -> reportError("Cannot execute object-value", node)
+ is LispData.LispExecutable -> {
+ resolvedValue.execute(this, node, stackFrame, rest)
+ }
+ }
+
+ }
+
+ else -> return reportError("Expected invocation", node)
+ }
+ }
+
+ fun resolveValue(stackFrame: StackFrame, node: LispAst.LispNode): LispData {
+ return when (node) {
+ is LispAst.Atom -> LispData.Atom(node.label)
+ is LispAst.Parenthesis -> executeLisp(stackFrame, node)
+ is LispAst.Reference -> stackFrame.resolveReference(node.label)
+ ?: reportError("Could not resolve variable ${node.label}", node)
+
+ is LispAst.StringLiteral -> LispData.string(node.parsedString)
+ }
+ }
+}
+
diff --git a/src/LispParser.kt b/src/LispParser.kt
new file mode 100644
index 0000000..1117397
--- /dev/null
+++ b/src/LispParser.kt
@@ -0,0 +1,116 @@
+package moe.nea.lisp
+
+import java.io.File
+
+class LispParser private constructor(filename: String, string: String) {
+ val racer = StringRacer(filename, string)
+ val program = parseProgram()
+
+ companion object {
+ fun parse(filename: String, string: String): LispAst.Program {
+ return LispParser(filename, string).program
+ }
+ fun parse(file: File): LispAst.Program {
+ return parse(file.absolutePath, file.readText())
+ }
+
+ val digits = "1234567890"
+ val alphabet = "abcdefghijklmnopqrstuvwxyz"
+ val validStartingIdentifiers = "-.#+*'!$%&/=?_~|^" + alphabet + alphabet.uppercase()
+ val validIdentifiers = validStartingIdentifiers + digits
+ val parenthesisMatches = mapOf(
+ "(" to ")",
+ "[" to "]",
+ "{" to "}",
+ "<" to ">",
+ )
+ }
+
+ fun parseProgram(): LispAst.Program {
+ val start = racer.idx
+ val nodes = mutableListOf<LispAst.LispNode>()
+ while (true) {
+ racer.skipWhitespace()
+ if (racer.finished())
+ break
+ nodes.add(parseNode())
+ }
+ return LispAst.Program(racer.span(start), nodes)
+ }
+
+ private fun parseNode(): LispAst.LispNode {
+ val start = racer.idx
+ val paren = racer.peekReq(1) ?: racer.error("Expected start of expression")
+ val matchingParen = parenthesisMatches[paren]
+ if (matchingParen != null) {
+ val paren = parseParenthesis(paren, matchingParen)
+ return LispAst.Parenthesis(racer.span(start), paren)
+ }
+ if (paren == "\"") {
+ return parseString()
+ }
+ if (paren == ":") {
+ return parseAtom()
+ }
+ val ident = parseIdentifier()
+ return LispAst.Reference(racer.span(start), ident)
+ }
+
+
+ fun parseAtom(): LispAst.Atom {
+ val start = racer.idx
+ racer.expect(":", "Expected : at start of atom")
+ val ident = parseIdentifier()
+ return LispAst.Atom(racer.span(start), ident)
+ }
+
+
+ fun parseIdentifier(): String {
+ return racer.consumeWhile { it.first() in validStartingIdentifiers && it.last() in validIdentifiers }.also {
+ if (it.isEmpty()) racer.error("Expected identifier")
+ }
+ }
+
+ fun parseString(): LispAst.StringLiteral {
+ val start = racer.idx
+ val quoted = parseQuotedString()
+ return LispAst.StringLiteral(racer.span(start), quoted)
+ }
+
+ fun parseQuotedString(): String {
+ racer.expect("\"", "Expected '\"' at string start")
+ val sb = StringBuilder()
+ while (true) {
+ when (val peek = racer.consumeCountReq(1)) {
+ "\"" -> break
+ "\\" -> {
+ val escaped = racer.consumeCountReq(1) ?: racer.error("Unfinished backslash escape")
+ if (escaped != "\"" && escaped != "\\") {
+ // Surprisingly i couldn't find unicode escapes to be generated by the original minecraft 1.8.9 implementation
+ racer.idx--
+ racer.error("Invalid backslash escape '$escaped'")
+ }
+ sb.append(escaped)
+ }
+
+ null -> racer.error("Unfinished string")
+ else -> {
+ sb.append(peek)
+ }
+ }
+ }
+ return sb.toString()
+ }
+
+ private fun parseParenthesis(opening: String, closing: String): List<LispAst.LispNode> {
+ val l = mutableListOf<LispAst.LispNode>()
+ racer.expect(opening, "Expected $opening")
+ while (true) {
+ racer.skipWhitespace()
+ if (racer.tryConsume(closing)) {
+ return l
+ }
+ l.add(parseNode())
+ }
+ }
+}
diff --git a/src/LispParsingError.kt b/src/LispParsingError.kt
new file mode 100644
index 0000000..f6e76de
--- /dev/null
+++ b/src/LispParsingError.kt
@@ -0,0 +1,4 @@
+package moe.nea.lisp
+
+data class LispParsingError(val baseString: String, val offset: Int, val mes0: String) :
+ Exception("$mes0 at $offset in `$baseString`.") \ No newline at end of file
diff --git a/src/LispPosition.kt b/src/LispPosition.kt
new file mode 100644
index 0000000..ea901a2
--- /dev/null
+++ b/src/LispPosition.kt
@@ -0,0 +1,21 @@
+package moe.nea.lisp
+
+data class LispPosition(
+ val start: Int,
+ val end: Int,
+ val fileName: String,
+ val fileContent: String,
+) : HasLispPosition {
+ val startLine by lazy { fileContent.substring(0, start).count { it == '\n' } + 1 }
+ val startColumn by lazy { start - fileContent.substring(0, start).indexOfLast { it == '\n' } }
+ val endLine by lazy { fileContent.substring(0, end).count { it == '\n' } + 1 }
+ val endColumn by lazy { end - fileContent.substring(0, end).indexOfLast { it == '\n' } }
+ override val position get() = this
+ override fun toString(): String {
+ return "at $fileName:$startLine:$startColumn until $endLine:$endColumn"
+ }
+}
+
+interface HasLispPosition {
+ val position: LispPosition
+}
diff --git a/src/StackFrame.kt b/src/StackFrame.kt
new file mode 100644
index 0000000..66d74b2
--- /dev/null
+++ b/src/StackFrame.kt
@@ -0,0 +1,32 @@
+package moe.nea.lisp
+
+class StackFrame(val parent: StackFrame?) {
+
+ val variables = mutableMapOf<String, LispData>()
+
+ interface MetaKey<T>
+
+ private val meta: MutableMap<MetaKey<*>, Any> = mutableMapOf()
+
+ fun <T : Any> getMeta(key: MetaKey<T>): T? {
+ return meta[key] as? T
+ }
+
+ fun <T : Any> setMeta(key: MetaKey<T>, value: T) {
+ meta[key] = value
+ }
+
+ fun resolveReference(label: String): LispData? =
+ variables[label] ?: parent?.resolveReference(label)
+
+ fun setValueLocal(label: String, value: LispData): LispData {
+ variables[label] = value
+ return value
+ }
+
+ fun fork(): StackFrame {
+ return StackFrame(this)
+ }
+
+
+}
diff --git a/src/StringRacer.kt b/src/StringRacer.kt
new file mode 100644
index 0000000..d0a4a15
--- /dev/null
+++ b/src/StringRacer.kt
@@ -0,0 +1,81 @@
+package moe.nea.lisp
+
+import java.util.*
+
+class StringRacer(val filename: String, val backing: String) {
+ var idx = 0
+ val stack = Stack<Int>()
+
+ fun pushState() {
+ stack.push(idx)
+ }
+
+ fun popState() {
+ idx = stack.pop()
+ }
+
+ fun span(start: Int) = LispPosition(start, idx, filename, backing)
+
+ fun discardState() {
+ stack.pop()
+ }
+
+ fun peek(count: Int): String {
+ return backing.substring(minOf(idx, backing.length), minOf(idx + count, backing.length))
+ }
+
+ fun finished(): Boolean {
+ return peek(1).isEmpty()
+ }
+
+ fun peekReq(count: Int): String? {
+ val p = peek(count)
+ if (p.length != count)
+ return null
+ return p
+ }
+
+ fun consumeCountReq(count: Int): String? {
+ val p = peekReq(count)
+ if (p != null)
+ idx += count
+ return p
+ }
+
+ fun tryConsume(string: String): Boolean {
+ val p = peek(string.length)
+ if (p != string)
+ return false
+ idx += p.length
+ return true
+ }
+
+ fun consumeWhile(shouldConsumeThisString: (String) -> Boolean): String {
+ var lastString: String = ""
+ while (true) {
+ val nextPart = peek(1)
+ if (nextPart.isEmpty()) break
+ val nextString = lastString + nextPart
+ if (!shouldConsumeThisString(nextString)) {
+ break
+ }
+ idx++
+ lastString = nextString
+ }
+ return lastString
+ }
+
+ fun expect(search: String, errorMessage: String) {
+ if (!tryConsume(search))
+ error(errorMessage)
+ }
+
+ fun error(errorMessage: String): Nothing {
+ throw LispParsingError(backing, idx, errorMessage)
+ }
+
+ fun skipWhitespace() {
+ consumeWhile { Character.isWhitespace(it.last()) }
+ }
+}
+
generated by cgit (git 2.46.0) at 2024-11-24 20:19:21 +0000