more on classes

universal args declaration parser, lambda code rewritten to it

library/src/commonMain/kotlin/net/sergeych/lyng/ArgsDeclaration.kt

@@ -0,0 +1,98 @@
+package net.sergeych.lyng
+
+/**
+ * List of argument declarations in the __definition__ of the lambda, class constructor,
+ * function, etc. It is created by [Compiler.parseArgsDeclaration]
+ */
+data class ArgsDeclaration(val args: List<Item>, val endTokenType: Token.Type) {
+    init {
+        val i = args.count { it.isEllipsis }
+        if (i > 1) throw ScriptError(args[i].pos, "there can be only one argument")
+    }
+
+    /**
+     * parse args and create local vars in a given context
+     */
+    suspend fun assignToContext(
+        context: Context,
+        fromArgs: Arguments = context.args,
+        defaultAccessType: Compiler.AccessType = Compiler.AccessType.Var
+    ) {
+        fun assign(a: Item, value: Obj) {
+            context.addItem(a.name, (a.accessType ?: defaultAccessType).isMutable, value)
+        }
+
+        suspend fun processHead(index: Int): Int {
+            var i = index
+            while (i != args.size) {
+                val a = args[i]
+                if (a.isEllipsis) break
+                val value = when {
+                    i < fromArgs.size -> fromArgs[i]
+                    a.defaultValue != null -> a.defaultValue.execute(context)
+                    else -> context.raiseArgumentError("too few arguments for the call")
+                }
+                assign(a, value)
+                i++
+            }
+            return i
+        }
+
+        suspend fun processTail(index: Int): Int {
+            var i = args.size - 1
+            var j = fromArgs.size - 1
+            while (i > index) {
+                val a = args[i]
+                if (a.isEllipsis) break
+                val value = when {
+                    j >= index -> {
+                        fromArgs[j--]
+                    }
+
+                    a.defaultValue != null -> a.defaultValue.execute(context)
+                    else -> context.raiseArgumentError("too few arguments for the call")
+                }
+                assign(a, value)
+                i--
+            }
+            return j
+        }
+
+        fun processEllipsis(index: Int, toFromIndex: Int) {
+            val a = args[index]
+            val l = if (index > toFromIndex) ObjList()
+            else ObjList( fromArgs.values.subList(index, toFromIndex+1).toMutableList())
+            assign(a, l)
+        }
+
+        val leftIndex = processHead(0)
+        if (leftIndex < args.size) {
+            val end = processTail(leftIndex)
+            processEllipsis(leftIndex, end)
+        }
+        else {
+            if( leftIndex < fromArgs.size)
+                context.raiseArgumentError("too many arguments for the call")
+        }
+    }
+
+    /**
+     * Single argument declaration descriptor.
+     *
+     * @param defaultValue default value, if set, can't be an [Obj] as it can depend on the call site, call args, etc.
+     *      If not null, could be executed on __caller context__ only.
+     */
+    data class Item(
+        val name: String,
+        val type: TypeDecl = TypeDecl.Obj,
+        val pos: Pos = Pos.builtIn,
+        val isEllipsis: Boolean = false,
+        /**
+         * Default value, if set, can't be an [Obj] as it can depend on the call site, call args, etc.
+         * So it is a [Statement] that must be executed on __caller context__.
+         */
+        val defaultValue: Statement? = null,
+        val accessType: Compiler.AccessType? = null,
+        val visibility: Compiler.Visibility? = null,
+    )
+}

library/src/commonMain/kotlin/net/sergeych/lyng/Arguments.kt

@@ -33,6 +33,7 @@ data class Arguments(val list: List<Info>) : Iterable<Obj> {
 
     companion object {
         val EMPTY = Arguments(emptyList())
+        fun from(values: Collection<Obj>) = Arguments(values.map { Info(it, Pos.UNKNOWN) })
     }
 
     override fun iterator(): Iterator<Obj> {

library/src/commonMain/kotlin/net/sergeych/lyng/Compiler.kt

@@ -347,22 +347,8 @@ class Compiler(
                 }
                 context.addItem("it", false, itValue)
             } else {
-                // assign vars as declared
+                // assign vars as declared the standard way
-                if (args.size != argsDeclaration.args.size && !argsDeclaration.args.last().isEllipsis)
+                argsDeclaration.assignToContext(context)
-                    raiseArgumentError("Too many arguments : called with ${args.size}, lambda accepts only ${argsDeclaration.args.size}")
-                for ((n, a) in argsDeclaration.args.withIndex()) {
-                    if (n >= args.size) {
-                        if (a.initialValue != null)
-                            context.addItem(a.name, false, a.initialValue.execute(context))
-                        else throw ScriptError(a.pos, "argument $n is out of scope")
-                    } else {
-                        val value = if (a.isEllipsis) {
-                            ObjList(args.values.subList(n, args.values.size).toMutableList())
-                        } else
-                            args[n]
-                        context.addItem(a.name, false, value)
-                    }
-                }
             }
             body.execute(context)
         }
@@ -411,29 +397,12 @@ class Compiler(
         }
     }
 
-    enum class AccessType {
+    enum class AccessType(val isMutable: Boolean) {
-        Val, Var, Default
+        Val(false), Var(true), Initialization(false)
     }
 
     enum class Visibility {
-        Default, Public, Private, Protected, Internal
+        Public, Private, Protected, Internal
-    }
-
-    data class ArgVar(
-        val name: String,
-        val type: TypeDecl = TypeDecl.Obj,
-        val pos: Pos,
-        val isEllipsis: Boolean,
-        val initialValue: Statement? = null,
-        val accessType: AccessType = AccessType.Default,
-        val visibility: Visibility = Visibility.Default
-    )
-
-    data class ArgsDeclaration(val args: List<ArgVar>, val endTokenType: Token.Type) {
-        init {
-            val i = args.indexOfFirst { it.isEllipsis }
-            if (i >= 0 && i != args.lastIndex) throw ScriptError(args[i].pos, "ellipsis argument must be last")
-        }
     }
 
     /**
@@ -441,7 +410,7 @@ class Compiler(
      * @return declaration or null if there is no valid list of arguments
      */
     private fun parseArgsDeclaration(cc: CompilerContext, isClassDeclaration: Boolean = false): ArgsDeclaration? {
-        val result = mutableListOf<ArgVar>()
+        val result = mutableListOf<ArgsDeclaration.Item>()
         var endTokenType: Token.Type? = null
         val startPos = cc.savePos()
 
@@ -484,7 +453,7 @@ class Compiler(
                             Visibility.Public
                         }
 
-                        else -> Visibility.Default
+                        else -> null
                     }
                     // val/var?
                     val access = when (t.value) {
@@ -504,7 +473,7 @@ class Compiler(
                             AccessType.Var
                         }
 
-                        else -> AccessType.Default
+                        else -> null
                     }
 
                     var defaultValue: Statement? = null
@@ -514,7 +483,15 @@ class Compiler(
                     // type information
                     val typeInfo = parseTypeDeclaration(cc)
                     val isEllipsis = cc.skipTokenOfType(Token.Type.ELLIPSIS, isOptional = true)
-                    result += ArgVar(t.value, typeInfo, t.pos, isEllipsis, defaultValue, access, visibility)
+                    result += ArgsDeclaration.Item(
+                        t.value,
+                        typeInfo,
+                        t.pos,
+                        isEllipsis,
+                        defaultValue,
+                        access,
+                        visibility
+                    )
 
                     // important: valid argument list continues with ',' and ends with '->' or ')'
                     // otherwise it is not an argument list:
@@ -714,24 +691,45 @@ class Compiler(
     private fun parseClassDeclaration(cc: CompilerContext, isStruct: Boolean): Statement {
         val nameToken = cc.requireToken(Token.Type.ID)
         val parsedArgs = parseArgsDeclaration(cc)
+
+        if( parsedArgs != null && parsedArgs.endTokenType != Token.Type.RPAREN)
+            throw ScriptError(nameToken.pos, "Bad class declaration: expected ')' at the end of the primary constructor")
+
         cc.skipTokenOfType(Token.Type.NEWLINE, isOptional = true)
         val t = cc.next()
-        if (t.type == Token.Type.LBRACE) {
+
+        var extraInit: Statement? = null
+        val bodyInit: Statement? = if (t.type == Token.Type.LBRACE) {
             // parse body
-        }
+            TODO("parse body")
+        } else null
+
         // create class
         val className = nameToken.value
+        lateinit var classContext: Context
 
-//        val constructorCode = statement {
+        val defaultAccess = if (isStruct) AccessType.Var else AccessType.Initialization
-//            val classContext = copy()
+        val defaultVisibility = Visibility.Public
-//        }
 
+        // create instance constructor
+        // create custom objClass with all fields and instance constructor
 
-        val newClass = ObjClass(className, parsedArgs?.args ?: emptyList())
+        val constructorCode = statement {
-//        statement {
+            // constructor code is registered with class instance and is called over
-//            addConst(nameToken.value, )
+            // new `thisObj` already set by class to ObjInstance
-//        }
+            thisObj as ObjInstance
-//        }
+            // the context now is a "class creation context", we must use its args to initialize
+            // fields. Note that 'this' is already set by class
+//            parsedArgs?.let { pa ->
+//                pa.extractArgs { (def, value) ->
+//                val access = def.accessType ?: defaultAccess
+//                val visibility = def.visibility ?: defaultVisibility
+//                addItem(def.name, access.isMutable, value)
+//            }
+//
+            thisObj
+
+        }
         TODO()
     }
 

library/src/commonMain/kotlin/net/sergeych/lyng/Context.kt

@@ -65,6 +65,9 @@ class Context(
     fun copy(pos: Pos, args: Arguments = Arguments.EMPTY,newThisObj: Obj? = null): Context =
         Context(this, args, pos, newThisObj ?: thisObj)
 
+    fun copy(args: Arguments = Arguments.EMPTY,newThisObj: Obj? = null): Context =
+        Context(this, args, pos, newThisObj ?: thisObj)
+
     fun copy() = Context(this, args, pos, thisObj)
 
     fun addItem(name: String, isMutable: Boolean, value: Obj?): StoredObj {

library/src/commonMain/kotlin/net/sergeych/lyng/ObjClass.kt

@@ -4,7 +4,7 @@ val ObjClassType by lazy { ObjClass("Class") }
 
 class ObjClass(
     val className: String,
-    val constructorArgs: List<Compiler.ArgVar> = emptyList(),
+    val constructorArgs: List<ArgsDeclaration.Item> = emptyList(),
     vararg val parents: ObjClass,
 ) : Obj() {
     constructor(

library/src/commonMain/kotlin/net/sergeych/lyng/ObjList.kt

@@ -1,6 +1,6 @@
 package net.sergeych.lyng
 
-class ObjList(val list: MutableList<Obj>) : Obj() {
+class ObjList(val list: MutableList<Obj> = mutableListOf()) : Obj() {
 
     init {
         for (p in objClass.parents)

library/src/commonMain/kotlin/net/sergeych/lyng/Pos.kt

@@ -16,6 +16,7 @@ data class Pos(val source: Source, val line: Int, val column: Int) {
 
     companion object {
         val builtIn = Pos(Source.builtIn, 0, 0)
+        val UNKNOWN = Pos(Source.UNKNOWN, -1, -1)
     }
 
 }

library/src/commonMain/kotlin/net/sergeych/lyng/Script.kt

@@ -119,6 +119,13 @@ class Script(
                     raiseError(ObjAssertionError(this,"Assertion failed"))
             }
 
+            addVoidFn("assertEquals") {
+                val a = requiredArg<Obj>(0)
+                val b = requiredArg<Obj>(1)
+                if( a.compareTo(this, b) != 0 )
+                    raiseError(ObjAssertionError(this,"Assertion failed: ${a.inspect()} == ${b.inspect()}"))
+            }
+
             addVoidFn("delay") {
                 delay((this.args.firstAndOnly().toDouble()/1000.0).roundToLong())
             }

library/src/commonMain/kotlin/net/sergeych/lyng/Source.kt

@@ -6,6 +6,7 @@ class Source(val fileName: String, text: String) {
 
     companion object {
         val builtIn: Source by lazy { Source("built-in", "") }
+        val UNKNOWN: Source by lazy { Source("UNKNOWN", "") }
     }
 
     val startPos: Pos = Pos(this, 0, 0)

library/src/commonTest/kotlin/ScriptTest.kt

@@ -486,6 +486,136 @@ class ScriptTest {
         )
     }
 
+    @Test
+    fun testAssignArgumentsNoEllipsis() = runTest {
+        // equal args, no ellipsis, no defaults, ok
+        val ttEnd = Token.Type.RBRACE
+        var pa = ArgsDeclaration(listOf(
+            ArgsDeclaration.Item("a"),
+            ArgsDeclaration.Item("b"),
+            ArgsDeclaration.Item("c"),
+        ), ttEnd)
+        var c = Context(pos = Pos.builtIn, args = Arguments.from(listOf(1,2,3).map { it.toObj() }))
+        pa.assignToContext(c)
+        assertEquals( ObjInt(1), c["a"]?.value)
+        assertEquals( ObjInt(2), c["b"]?.value)
+        assertEquals( ObjInt(3), c["c"]?.value)
+        // less args: error
+        c = Context(pos = Pos.builtIn, args = Arguments.from(listOf(1,2).map { it.toObj() }))
+        assertFailsWith<ScriptError> {
+            pa.assignToContext(c)
+        }
+        // less args, no ellipsis, defaults, ok
+        pa = ArgsDeclaration(listOf(
+            ArgsDeclaration.Item("a"),
+            ArgsDeclaration.Item("b"),
+            ArgsDeclaration.Item("c", defaultValue = statement { ObjInt(100) }),
+        ), ttEnd)
+        pa.assignToContext(c)
+        assertEquals( ObjInt(1), c["a"]?.value)
+        assertEquals( ObjInt(2), c["b"]?.value)
+        assertEquals( ObjInt(100), c["c"]?.value)
+        // enough args. default value is ignored:
+        c = Context(pos = Pos.builtIn, args = Arguments.from(listOf(10, 2, 5).map { it.toObj() }))
+        pa.assignToContext(c)
+        assertEquals( ObjInt(10), c["a"]?.value)
+        assertEquals( ObjInt(2), c["b"]?.value)
+        assertEquals( ObjInt(5), c["c"]?.value)
+    }
+
+    @Test
+    fun testAssignArgumentsEndEllipsis() = runTest {
+        // equal args,
+        // less args, no ellipsis, defaults, ok
+        val ttEnd = Token.Type.RBRACE
+        var pa = ArgsDeclaration(listOf(
+            ArgsDeclaration.Item("a"),
+            ArgsDeclaration.Item("b", isEllipsis = true),
+        ), ttEnd)
+        var c = Context(args = Arguments.from(listOf(1,2,3).map { it.toObj() }))
+        pa.assignToContext(c)
+        c.eval("assert( a == 1 ); println(b)")
+        c.eval("assert( b == [2,3] )")
+
+        c = Context(args = Arguments.from(listOf(1,2).map { it.toObj() }))
+        pa.assignToContext(c)
+        c.eval("assertEquals( a, 1 ); println(b)")
+        c.eval("assertEquals( b, [2] )")
+
+        c = Context(args = Arguments.from(listOf(1).map { it.toObj() }))
+        pa.assignToContext(c)
+        c.eval("assert( a == 1 ); println(b)")
+        c.eval("assert( b == [] )")
+    }
+
+    @Test
+    fun testAssignArgumentsStartEllipsis() = runTest {
+        val ttEnd = Token.Type.RBRACE
+        var pa = ArgsDeclaration(listOf(
+            ArgsDeclaration.Item("a", isEllipsis = true),
+            ArgsDeclaration.Item("b"),
+            ArgsDeclaration.Item("c"),
+        ), ttEnd)
+        var c = Context(args = Arguments.from(listOf(0,1,2,3).map { it.toObj() }))
+        pa.assignToContext(c)
+        c.eval("assertEquals( a,[0,1] )")
+        c.eval("assertEquals( b, 2 )")
+        c.eval("assertEquals( c, 3 )")
+
+        c = Context(args = Arguments.from(listOf(1,2,3).map { it.toObj() }))
+        pa.assignToContext(c)
+        c.eval("assertEquals( a,[1] )")
+        c.eval("assertEquals( b, 2 )")
+        c.eval("assertEquals( c, 3 )")
+
+        c = Context(args = Arguments.from(listOf(2,3).map { it.toObj() }))
+        pa.assignToContext(c)
+        c.eval("assertEquals( a,[] )")
+        c.eval("assertEquals( b, 2 )")
+        c.eval("assertEquals( c, 3 )")
+
+        c = Context(args = Arguments.from(listOf(3).map { it.toObj() }))
+        assertFailsWith<ExecutionError> {
+            pa.assignToContext(c)
+        }
+    }
+
+    @Test
+    fun testAssignArgumentsmiddleEllipsis() = runTest {
+        val ttEnd = Token.Type.RBRACE
+        var pa = ArgsDeclaration(listOf(
+            ArgsDeclaration.Item("i"),
+            ArgsDeclaration.Item("a", isEllipsis = true),
+            ArgsDeclaration.Item("b"),
+            ArgsDeclaration.Item("c"),
+        ), ttEnd)
+        var c = Context(args = Arguments.from(listOf(-1,0,1,2,3).map { it.toObj() }))
+        pa.assignToContext(c)
+        c.eval("assertEquals( i, -1 )")
+        c.eval("assertEquals( a,[0,1] )")
+        c.eval("assertEquals( b, 2 )")
+        c.eval("assertEquals( c, 3 )")
+
+        c = Context(args = Arguments.from(listOf(0, 1,2,3).map { it.toObj() }))
+        pa.assignToContext(c)
+        c.eval("assertEquals( i, 0 )")
+        c.eval("assertEquals( a,[1] )")
+        c.eval("assertEquals( b, 2 )")
+        c.eval("assertEquals( c, 3 )")
+
+        c = Context(args = Arguments.from(listOf(1,2,3).map { it.toObj() }))
+        pa.assignToContext(c)
+        c.eval("assertEquals( i, 1)")
+        c.eval("assertEquals( a,[] )")
+        c.eval("assertEquals( b, 2 )")
+        c.eval("assertEquals( c, 3 )")
+
+        c = Context(args = Arguments.from(listOf(2,3).map { it.toObj() }))
+        assertFailsWith<ExecutionError> {
+            pa.assignToContext(c)
+        }
+    }
+
     @Test
     fun testWhileBlockIsolation1() = runTest {
         eval(