Check whether student coded a control statement correctly

Check whether student coded a control statement correctly

check_if_else(state, index = 1, not_found_msg = NULL, append = TRUE)

check_while(state, index = 1, not_found_msg = NULL, append = TRUE)

check_for(state, index = 1, not_found_msg = NULL, append = TRUE)

check_cond(state)

# S3 method for ControlState
check_body(state, ...)

check_if(state)

check_else(state, not_found_msg = NULL, append = TRUE)

Arguments

state	state to start from (for check_ functions)
index	Number of that particular control statement to check
not_found_msg	Custom message in case the control statement was not found
append	Whether or not to append the feedback to feedback built in previous states
...	S3 stuff

Examples

if (FALSE) {
# Example 1: if else
vec <- c("a", "b", "c")
if("a" %in% vec) {
 print("a in here")
} else if(any("b" > vec)) {
 cat("b not smallest")
} else {
 str(vec)
}

# SCT
check_if_else(1) %>%  {
  check_cond(.) %>% {
    check_code(., "%in%")
    check_code(., "vec")
  }
  check_if(.) %>% check_function(., "print")
  check_else(.) %>% check_if_else() %>% {
    check_cond(.) %>% check_code(">")
    check_if(.) %>% check_function("cat")
    check_else(.) %>% check_function("str")
  }
}

# Example 2: while loop
while(x < 18) {
 x <- x + 5
 print(x)
}

# SCT
check_while(1) %>% {
  check_cond(.) %>% check_code(c("< 18", "18 >"))
  check_body(.) %>% {
    check_code(., c("x + 5", "5 + x"))
    check_function(., "print") %>% test_arg("x")
  }
}

# Example 3: for loop
for(i in 1:5) {
 print("hurray!")
}

# SCT
ex() %>% check_for() %>% {
  check_cond(.) %>% {
    check_code(., "in")
    check_code(., "1")
    check_code(., "5")
  }
  check_body(.) %>% check_function("print") %>% check_arg("x") %>% check_equal()
}
}