fix #31 type records for simple types and extern keyword for methods/functions

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

@@ -110,7 +110,7 @@ data class ArgsDeclaration(val params: List<Item>, val endTokenType: Token.Type)
      */
     data class Item(
         val name: String,
-        val type: TypeDecl = TypeDecl.Obj,
+        val type: TypeDecl = TypeDecl.TypeAny,
         val pos: Pos = Pos.builtIn,
         val isEllipsis: Boolean = false,
         /**

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

@@ -560,11 +560,11 @@ class Compiler(
     }
 
     private fun parseTypeDeclaration(cc: CompilerContext): TypeDecl {
-        val result = TypeDecl.Obj
+        return if (cc.skipTokenOfType(Token.Type.COLON, isOptional = true)) {
-        cc.ifNextIs(Token.Type.COLON) {
+            val tt = cc.requireToken(Token.Type.ID, "type name or type expression required")
-            TODO("parse type declaration here")
+            val isNullable = cc.skipTokenOfType(Token.Type.QUESTION, isOptional = true)
-        }
+            TypeDecl.Simple(tt.value, isNullable)
-        return result
+        } else TypeDecl.TypeAny
     }
 
     /**
@@ -590,6 +590,8 @@ class Compiler(
                     cc.previous()
                     parseExpression(cc)?.let { args += ParsedArgument(it, t.pos) }
                         ?: throw ScriptError(t.pos, "Expecting arguments list")
+                    if (cc.current().type == Token.Type.COLON)
+                        parseTypeDeclaration(cc)
                     // Here should be a valid termination:
                 }
             }
@@ -724,7 +726,7 @@ class Compiler(
     }
 
     /**
-     * Parse keyword-starting statenment.
+     * Parse keyword-starting statement.
      * @return parsed statement or null if, for example. [id] is not among keywords
      */
     private fun parseKeywordStatement(id: Token, cc: CompilerContext): Statement? = when (id.value) {
@@ -735,7 +737,6 @@ class Compiler(
         "for" -> parseForStatement(cc)
         "break" -> parseBreakStatement(id.pos, cc)
         "continue" -> parseContinueStatement(id.pos, cc)
-        "fn", "fun" -> parseFunctionDeclaration(cc)
         "if" -> parseIfStatement(cc)
         "class" -> parseClassDeclaration(cc, false)
         "try" -> parseTryStatement(cc)
@@ -744,11 +745,16 @@ class Compiler(
         else -> {
             // triples
             cc.previous()
+            val isExtern = cc.skipId("extern")
             when {
-                cc.matchQualifiers("fun", "private") -> parseFunctionDeclaration(cc, Visibility.Private)
+                cc.matchQualifiers("fun", "private") -> parseFunctionDeclaration(cc, Visibility.Private, isExtern)
-                cc.matchQualifiers("fn", "private") -> parseFunctionDeclaration(cc, Visibility.Private)
+                cc.matchQualifiers("fn", "private") -> parseFunctionDeclaration(cc, Visibility.Private, isExtern)
-                cc.matchQualifiers("fun", "open") -> parseFunctionDeclaration(cc, isOpen = true)
+                cc.matchQualifiers("fun", "open") -> parseFunctionDeclaration(cc, isOpen = true, isExtern = isExtern)
-                cc.matchQualifiers("fn", "open") -> parseFunctionDeclaration(cc, isOpen = true)
+                cc.matchQualifiers("fn", "open") -> parseFunctionDeclaration(cc, isOpen = true, isExtern = isExtern)
+
+                cc.matchQualifiers("fun") -> parseFunctionDeclaration(cc, isOpen = false, isExtern = isExtern)
+                cc.matchQualifiers("fn") -> parseFunctionDeclaration(cc, isOpen = false, isExtern = isExtern)
+
                 cc.matchQualifiers("val", "private") -> parseVarDeclaration(false, Visibility.Private, cc)
                 cc.matchQualifiers("var", "private") -> parseVarDeclaration(true, Visibility.Private, cc)
                 cc.matchQualifiers("val", "open") -> parseVarDeclaration(false, Visibility.Private, cc, true)
@@ -1419,29 +1425,35 @@ class Compiler(
     }
 
     private fun parseFunctionDeclaration(
-        tokens: CompilerContext,
+        cc: CompilerContext,
         visibility: Visibility = Visibility.Public,
-        @Suppress("UNUSED_PARAMETER") isOpen: Boolean = false
+        @Suppress("UNUSED_PARAMETER") isOpen: Boolean = false,
+        isExtern: Boolean = false
     ): Statement {
-        var t = tokens.next()
+        var t = cc.next()
         val start = t.pos
         val name = if (t.type != Token.Type.ID)
             throw ScriptError(t.pos, "Expected identifier after 'fn'")
         else t.value
 
-        t = tokens.next()
+        t = cc.next()
         if (t.type != Token.Type.LPAREN)
             throw ScriptError(t.pos, "Bad function definition: expected '(' after 'fn ${name}'")
 
-        val argsDeclaration = parseArgsDeclaration(tokens)
+        val argsDeclaration = parseArgsDeclaration(cc)
         if (argsDeclaration == null || argsDeclaration.endTokenType != Token.Type.RPAREN)
             throw ScriptError(
                 t.pos,
                 "Bad function definition: expected valid argument declaration or () after 'fn ${name}'"
             )
 
+        if (cc.current().type == Token.Type.COLON) parseTypeDeclaration(cc)
+
         // Here we should be at open body
-        val fnStatements = parseBlock(tokens)
+        val fnStatements = if (isExtern)
+            statement { raiseError("extern function not provided: $name") }
+        else
+            parseBlock(cc)
 
         var closure: Context? = null
 

lynglib/src/commonMain/kotlin/net/sergeych/lyng/CompilerContext.kt

@@ -53,6 +53,20 @@ internal class CompilerContext(val tokens: List<Token>) {
 
     fun currentPos(): Pos = tokens[currentIndex].pos
 
+    /**
+     * If the next token is identifier `name`, skip it and return `true`.
+     * else leave where it is and return `false`
+     */
+    fun skipId(name: String): Boolean {
+        current().let { t ->
+            if( t.type == Token.Type.ID && t.value == name ) {
+                next()
+                return true
+            }
+        }
+        return false
+    }
+
     /**
      * Skips next token if its type is `tokenType`, returns `true` if so.
      * @param errorMessage message to throw if next token is not `tokenType`
@@ -96,7 +110,6 @@ internal class CompilerContext(val tokens: List<Token>) {
         }
     }
 
-    @Suppress("NOTHING_TO_INLINE")
     inline fun addBreak() {
         breakFound = true
     }

lynglib/src/commonMain/kotlin/net/sergeych/lyng/TypeDecl.kt

@@ -1,9 +1,14 @@
+@file:Suppress("unused")
+
 package net.sergeych.lyng
 
 // this is highly experimental and subject to complete redesign
 // very soon
-sealed class TypeDecl {
+sealed class TypeDecl(val isNullable:Boolean = false) {
     // ??
 //    data class Fn(val argTypes: List<ArgsDeclaration.Item>, val retType: TypeDecl) : TypeDecl()
-    object Obj : TypeDecl()
+    object TypeAny : TypeDecl()
+    object TypeNullableAny : TypeDecl(true)
+
+    class Simple(val name: String,isNullable: Boolean) : TypeDecl(isNullable)
 }

lynglib/src/commonTest/kotlin/TypesTest.kt

@@ -1,10 +1,53 @@
 import kotlinx.coroutines.test.runTest
+import net.sergeych.lyng.eval
 import kotlin.test.Test
 
 class TypesTest {
 
     @Test
     fun testTypeCollection1() = runTest {
+        eval("""
+           class Point(x: Real, y: Real)
+           assert(Point(1,2).x == 1)
+           assert(Point(1,2).y == 2)
+           assert(Point(1,2) is Point)
+        """.trimIndent())
 
     }
+    @Test
+    fun testTypeCollection2() = runTest {
+        eval("""
+           fun fn1(x: Real, y: Real): Real { x + y }
+        """.trimIndent())
+
+    }
+    @Test
+    fun testTypeCollection3() = runTest {
+        eval("""
+           class Test(a: Int) {
+              fun fn1(x: Real, y: Real): Real { x + y }
+           }
+        """.trimIndent())
+    }
+
+    @Test
+    fun testExternDeclarations() = runTest {
+        eval("""
+            extern fun foo1(a: String): Void
+            assertThrows { foo1("1") }
+           class Test(a: Int) {
+              extern fun fn1(x: Real, y: Real): Real
+//              extern val b: Int
+           }
+//           println("1")
+           val t = Test(0)
+//           println(t.b)
+//           println("2")
+           assertThrows {
+            t.fn1(1,2)
+           }
+//           println("4")
+           
+        """.trimIndent())
+    }
 }