100% coverage

R/simplify.R

@@ -74,12 +74,16 @@ simplify_exponentiation <- function(f, g) {
   call("^", left, right)
 }
 
+# FIXME: I don't handle named arguments here...
 .simplify_built_in_functions <- c("sin", "cos", "exp")
-simplify_built_in_function <- function(expr, x) {
+simplify_built_in_function <- function(expr) {
   call_name <- as.character(expr[[1]])
-  arguments <- Map(simplify_expr, expr[[-1]])
-  if (all(is.numeric(arguments))) do.call(call_name, arguments)
-  else do.call("call", call_name, arguments)
+  arguments <- vector("list", length(expr) - 1)
+  for (i in seq_along(arguments)) {
+    arguments[i] <- list(simplify_expr(expr[[i + 1]]))
+  }
+  if (all(unlist(Map(is.numeric, arguments)))) do.call(call_name, arguments)
+  else do.call("call", c(list(call_name), arguments), quote = TRUE)
 }
 
 simplify_call <- function(expr) {

tests/testthat/test-simpification.R

@@ -50,3 +50,14 @@ test_that("we can do some simplifications when there are variables involved", {
 
   expect_equal(simplify_expr(quote(x ^ y)), quote(x ^ y))
 })
+
+test_that("we can handle some simple functions", {
+  expect_equal(simplify_expr(quote(sin(x))), quote(sin(x)))
+  expect_equal(simplify_expr(quote(sin(1*x))), quote(sin(x)))
+
+  expect_equal(simplify_expr(quote(sin(0*x))), 0)
+})
+
+test_that("we handle errors correctly", {
+  expect_error(simplify_expr(quote(x %in% y)))
+})