fixed bug with callable argument in calls, added more docs

docs/tutorial.md

@@ -316,6 +316,14 @@ one could be with ellipsis that means "the rest pf arguments as List":
     assert( { a, b...-> [a,...b] }(100, 1, 2, 3) == [100, 1, 2, 3]) 
     void
 
+### Using lambda as the parameter
+
+    fun mapValues(iterable, transform) {
+        var result = []
+        for( x in iterable ) result += transform(x)
+    }
+    assert( [11, 21, 31] == mapValues( [1,2,3], { it*10+1 }))
+    >>> void
 
 # Lists (aka arrays)
 

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

@@ -499,7 +499,7 @@ class Compiler(
 
                 else -> {
                     cc.previous()
-                    parseStatement(cc)?.let { args += ParsedArgument(it, t.pos) }
+                    parseExpression(cc)?.let { args += ParsedArgument(it, t.pos) }
                         ?: throw ScriptError(t.pos, "Expecting arguments list")
                 }
             }

library/src/commonTest/kotlin/ScriptTest.kt

@@ -1138,7 +1138,8 @@ class ScriptTest {
 
     @Test
     fun testIsPrimeSampleBug() = runTest {
-        eval("""
+        eval(
+            """
                 fun naive_is_prime(candidate) {
                     val x = if( candidate !is Int) candidate.toInt() else candidate
                     var divisor = 1
@@ -1151,6 +1152,20 @@ class ScriptTest {
                 }
                 naive_is_prime(4)
     
-        """.trimIndent())
+        """.trimIndent()
+        )
+    }
+
+    @Test
+    fun testLambdaAsFnCallArg() = runTest {
+        eval(
+            """
+            fun mapValues(iterable, transform) {
+                var result = []
+                for( x in iterable ) result += transform(x)
+            }
+            assert( [11, 21, 31] == mapValues( if( true) [1,2,3] else [10], { it*10+1 }))
+    """.trimIndent()
+        )
     }
 }