Data commit

Task/Extend-your-language/R/extend-your-language-1.r

@@ -0,0 +1,8 @@
+if2 <- function(condition1, condition2, both_true, first_true, second_true, both_false)
+{
+  expr <- if(condition1)
+  {
+    if(condition2) both_true else first_true
+  } else if(condition2) second_true else both_false
+  eval(expr)
+}

Task/Extend-your-language/R/extend-your-language-2.r

@@ -0,0 +1,12 @@
+for(x in 1:2) for(y in letters[1:2])
+{
+  print(if2(x == 1, y == "a",
+    "both conditions are true",
+    x + 99,
+    {
+      yy <- rep.int(y, 10)
+      paste(letters[1:10], yy)
+    },
+    NULL
+  ))
+}

Task/Extend-your-language/R/extend-your-language-3.r

@@ -0,0 +1,10 @@
+if2 <- function(condition1, condition2, expr_list = NULL)
+{
+  cl <- as.call(expr_list)
+  cl_name <- if(condition1)
+  {
+    if(condition2) "" else "else1"
+  } else if(condition2) "else2" else "else"
+  if(!nzchar(cl_name)) cl_name <- which(!nzchar(names(cl)))
+  eval(cl[[cl_name]])
+}

Task/Extend-your-language/R/extend-your-language-4.r

@@ -0,0 +1,13 @@
+for(x in 1:2) for(y in letters[1:2])
+{
+  print(if2(x == 1, y == "a", list(
+    "both conditions are true",
+    else1 = x + 99,
+    else2 =
+    {
+      yy <- rep.int(y, 10)
+      paste(letters[1:10], yy)
+    },
+    "else" = NULL
+  )))
+}