fix #23 string formatting and manipulations

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

@@ -33,6 +33,13 @@ data class Arguments(val list: List<Obj>,val tailBlockMode: Boolean = false) : L
         return list.first()
     }
 
+    /**
+     * Convert to list of kotlin objects, see [Obj.toKotlin].
+     */
+    suspend fun toKotlinList(context: Context): List<Any?> {
+        return list.map { it.toKotlin(context) }
+    }
+
     companion object {
         val EMPTY = Arguments(emptyList())
         fun from(values: Collection<Obj>) = Arguments(values.toList())

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

@@ -59,7 +59,7 @@ class Compiler(
                         parseBlock(cc)
                 }
 
-                Token.Type.RBRACE -> {
+                Token.Type.RBRACE, Token.Type.RBRACKET -> {
                     cc.previous()
                     return null
                 }
@@ -226,8 +226,7 @@ class Compiler(
                         val index = parseStatement(cc) ?: throw ScriptError(t.pos, "Expecting index expression")
                         cc.skipTokenOfType(Token.Type.RBRACKET, "missing ']' at the end of the list literal")
                         operand = Accessor({ cxt ->
-                            val i = (index.execute(cxt) as? ObjInt)?.value?.toInt()
-                                ?: cxt.raiseError("index must be integer")
+                            val i = index.execute(cxt)
                             val x = left.getter(cxt).value
                             if( x == ObjNull && isOptional) ObjNull.asReadonly
                             else x.getAt(cxt, i).asMutable
@@ -341,10 +340,10 @@ class Compiler(
                 }
 
                 Token.Type.DOTDOT, Token.Type.DOTDOTLT -> {
-                    // closed-range operator
+                    // range operator
                     val isEndInclusive = t.type == Token.Type.DOTDOT
                     val left = operand
-                    val right = parseStatement(cc)
+                    val right = parseExpression(cc)
                     operand = Accessor {
                         ObjRange(
                             left?.getter?.invoke(it)?.value ?: ObjNull,
@@ -366,11 +365,15 @@ class Compiler(
                     } ?: parseLambdaExpression(cc)
                 }
 
+                Token.Type.RBRACKET -> {
+                    cc.previous()
+                    return operand
+                }
 
                 else -> {
                     cc.previous()
                     operand?.let { return it }
-                    operand = parseAccessor(cc) ?: throw ScriptError(t.pos, "Expecting expression")
+                    operand = parseAccessor(cc) ?: return null //throw ScriptError(t.pos, "Expecting expression")
                 }
             }
         }
@@ -1115,7 +1118,7 @@ class Compiler(
                     var breakCaught = false
 
                     if (size > 0) {
-                        var current = runCatching { sourceObj.getAt(forContext, 0) }
+                        var current = runCatching { sourceObj.getAt(forContext, ObjInt(0)) }
                             .getOrElse {
                                 throw ScriptError(
                                     tOp.pos,
@@ -1142,7 +1145,7 @@ class Compiler(
                                 }
                             } else result = body.execute(forContext)
                             if (++index >= size) break
-                            current = sourceObj.getAt(forContext, index)
+                            current = sourceObj.getAt(forContext, ObjInt(index.toLong()))
                         }
                     }
                     if (!breakCaught && elseStatement != null) {

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

@@ -42,6 +42,9 @@ data class Accessor(
 }
 
 open class Obj {
+
+    val isNull by lazy { this === ObjNull }
+
     var isFrozen: Boolean = false
 
     private val monitor = Mutex()
@@ -176,6 +179,13 @@ open class Obj {
         context.raiseNotImplemented()
     }
 
+    /**
+     * Convert Lyng object to its Kotlin counterpart
+     */
+    open suspend fun toKotlin(context: Context): Any? {
+        return toString()
+    }
+
     fun willMutate(context: Context) {
         if (isFrozen) context.raiseError("attempt to mutate frozen object")
     }
@@ -201,7 +211,7 @@ open class Obj {
         if (field.isMutable) field.value = newValue else context.raiseError("can't assign to read-only field: $name")
     }
 
-    open suspend fun getAt(context: Context, index: Int): Obj {
+    open suspend fun getAt(context: Context, index: Obj): Obj {
         context.raiseNotImplemented("indexing")
     }
 
@@ -297,7 +307,7 @@ object ObjNull : Obj() {
         context.raiseNPE()
     }
 
-    override suspend fun getAt(context: Context, index: Int): Obj {
+    override suspend fun getAt(context: Context, index: Obj): Obj {
         context.raiseNPE()
     }
 
@@ -310,6 +320,10 @@ object ObjNull : Obj() {
     }
 
     override fun toString(): String = "null"
+
+    override suspend fun toKotlin(context: Context): Any? {
+        return null
+    }
 }
 
 interface Numeric {

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

@@ -18,6 +18,10 @@ data class ObjBool(val value: Boolean) : Obj() {
 
     override suspend fun logicalOr(context: Context, other: Obj): Obj = ObjBool(value || other.toBool())
 
+    override suspend fun toKotlin(context: Context): Any {
+        return value
+    }
+
     companion object {
         val type = ObjClass("Bool")
     }

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

@@ -162,7 +162,7 @@ val ObjArray by lazy {
         addFn("contains", isOpen = true) {
             val obj = args.firstAndOnly()
             for( i in 0..< thisObj.invokeInstanceMethod(this, "size").toInt()) {
-                if( thisObj.getAt(this, i).compareTo(this, obj) == 0 ) return@addFn ObjTrue
+                if( thisObj.getAt(this, ObjInt(i.toLong())).compareTo(this, obj) == 0 ) return@addFn ObjTrue
             }
             ObjFalse
         }

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

@@ -72,6 +72,10 @@ data class ObjInt(var value: Long) : Obj(), Numeric {
         } else null
     }
 
+    override suspend fun toKotlin(context: Context): Any {
+        return value
+    }
+
     companion object {
         val type = ObjClass("Int")
     }

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

@@ -11,15 +11,15 @@ class ObjList(val list: MutableList<Obj> = mutableListOf()) : Obj() {
         list.joinToString(separator = ", ") { it.inspect() }
     }]"
 
-    fun normalize(context: Context, index: Int, allowisEndInclusive: Boolean = false): Int {
+    fun normalize(context: Context, index: Int, allowsEndInclusive: Boolean = false): Int {
         val i = if (index < 0) list.size + index else index
-        if (allowisEndInclusive && i == list.size) return i
+        if (allowsEndInclusive && i == list.size) return i
         if (i !in list.indices) context.raiseError("index $index out of bounds for size ${list.size}")
         return i
     }
 
-    override suspend fun getAt(context: Context, index: Int): Obj {
-        val i = normalize(context, index)
+    override suspend fun getAt(context: Context, index: Obj): Obj {
+        val i = normalize(context, index.toInt())
         return list[i]
     }
 
@@ -82,6 +82,10 @@ class ObjList(val list: MutableList<Obj> = mutableListOf()) : Obj() {
     override val objClass: ObjClass
         get() = type
 
+    override suspend fun toKotlin(context: Context): Any {
+        return list.map { it.toKotlin(context) }
+    }
+
     companion object {
         val type = ObjClass("List", ObjArray).apply {
 
@@ -92,7 +96,7 @@ class ObjList(val list: MutableList<Obj> = mutableListOf()) : Obj() {
             )
             addFn("getAt") {
                 requireExactCount(1)
-                thisAs<ObjList>().getAt(this, requiredArg<ObjInt>(0).value.toInt())
+                thisAs<ObjList>().getAt(this, requiredArg<Obj>(0))
             }
             addFn("putAt") {
                 requireExactCount(2)
@@ -113,7 +117,7 @@ class ObjList(val list: MutableList<Obj> = mutableListOf()) : Obj() {
                     val l = thisAs<ObjList>()
                     var index = l.normalize(
                         this, requiredArg<ObjInt>(0).value.toInt(),
-                        allowisEndInclusive = true
+                        allowsEndInclusive = true
                     )
                     for (i in 1..<args.size) l.list.add(index++, args[i])
                     ObjVoid

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

@@ -36,6 +36,13 @@ data class ObjReal(val value: Double) : Obj(), Numeric {
     override suspend fun mod(context: Context, other: Obj): Obj =
         ObjReal(this.value % other.toDouble())
 
+    /**
+     * Returns unboxed Double value
+     */
+    override suspend fun toKotlin(context: Context): Any {
+        return value
+    }
+
     companion object {
         val type: ObjClass = ObjClass("Real").apply {
             createField(

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

@@ -2,11 +2,20 @@ package net.sergeych.lyng
 
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
+import net.sergeych.sprintf.sprintf
 
 @Serializable
 @SerialName("string")
 data class ObjString(val value: String) : Obj() {
 
+//    fun normalize(context: Context, index: Int, allowsEndInclusive: Boolean = false): Int {
+//        val i = if (index < 0) value.length + index else index
+//        if (allowsEndInclusive && i == value.length) return i
+//        if (i !in value.indices) context.raiseError("index $index out of bounds for length ${value.length} of \"$value\"")
+//        return i
+//    }
+
+
     override suspend fun compareTo(context: Context, other: Obj): Int {
         if (other !is ObjString) return -2
         return this.value.compareTo(other.value)
@@ -27,8 +36,21 @@ data class ObjString(val value: String) : Obj() {
         return ObjString(value + other.asStr.value)
     }
 
-    override suspend fun getAt(context: Context, index: Int): Obj {
-        return ObjChar(value[index])
+    override suspend fun getAt(context: Context, index: Obj): Obj {
+        if( index is ObjInt ) return ObjChar(value[index.toInt()])
+        if( index is ObjRange ) {
+            val start = if(index.start == null || index.start.isNull) 0 else  index.start.toInt()
+            val end = if( index.end  == null || index.end.isNull ) value.length else  {
+                val e = index.end.toInt()
+                if( index.isEndInclusive) e + 1 else e
+            }
+            return ObjString(value.substring(start, end))
+        }
+        context.raiseArgumentError("String index must be Int or Range")
+    }
+
+    override suspend fun callOn(context: Context): Obj {
+        return ObjString(this.value.sprintf(*context.args.toKotlinList(context).toTypedArray()))
     }
 
     override suspend fun contains(context: Context, other: Obj): Boolean {
@@ -41,10 +63,12 @@ data class ObjString(val value: String) : Obj() {
 
     companion object {
         val type = ObjClass("String").apply {
-            addConst("startsWith",
-                statement {
-                    ObjBool(thisAs<ObjString>().value.startsWith(requiredArg<ObjString>(0).value))
-                })
+            addFn("startsWith") {
+                ObjBool(thisAs<ObjString>().value.startsWith(requiredArg<ObjString>(0).value))
+            }
+            addFn("endsWith") {
+                ObjBool(thisAs<ObjString>().value.endsWith(requiredArg<ObjString>(0).value))
+            }
             addConst("length",
                 statement { ObjInt(thisAs<ObjString>().value.length.toLong()) }
             )