Use "can't" phrasing in headers of subscript errors (#1736)

Author: lionel-

R/subscript.R

@@ -175,12 +175,20 @@ new_error_subscript_type <- function(i,
 
 #' @export
 cnd_header.vctrs_error_subscript_type <- function(cnd) {
-  action <- cnd_subscript_action(cnd)
+  arg <- cnd[["subscript_arg"]]
+  if (is_subscript_arg(arg)) {
+    with <- glue::glue(" with {format_subscript_arg(arg)}")
+  } else {
+    with <- ""
+  }
+
+  action <- cnd_subscript_action(cnd, assign_to = FALSE)
   elt <- cnd_subscript_element(cnd)
+
   if (cnd_subscript_scalar(cnd)) {
-    glue::glue("Must {action} {elt[[1]]} with a single valid subscript.")
+    glue::glue("Can't {action} {elt[[1]]}{with}.")
   } else {
-    glue::glue("Must {action} {elt[[2]]} with a valid subscript vector.")
+    glue::glue("Can't {action} {elt[[2]]}{with}.")
   }
 }
 #' @export

tests/testthat/_snaps/error-call.md

@@ -218,7 +218,7 @@
     Output
       <error/vctrs_error_subscript_type>
       Error in `my_function()`:
-      ! Must subset elements with a valid subscript vector.
+      ! Can't subset elements with `my_arg`.
       x Can't convert from `my_arg` <double> to <integer> due to loss of precision.
 
 ---
@@ -228,7 +228,7 @@
     Output
       <error/vctrs_error_subscript_type>
       Error in `my_function()`:
-      ! Must subset elements with a valid subscript vector.
+      ! Can't subset elements.
       x Can't convert from <double> to <integer> due to loss of precision.
 
 ---
@@ -238,7 +238,7 @@
     Output
       <error/vctrs_error_subscript_type>
       Error in `my_function()`:
-      ! Must subset elements with a valid subscript vector.
+      ! Can't subset elements with `my_arg`.
       x `my_arg` must be logical, numeric, or character, not an empty list.
 
 ---
@@ -258,7 +258,7 @@
     Output
       <error/vctrs_error_subscript_type>
       Error in `my_function()`:
-      ! Must subset elements with a valid subscript vector.
+      ! Can't subset elements.
       x Subscript can't contain missing values.
       x It has a missing value at location 1.
 
@@ -326,7 +326,7 @@
     Output
       <error/vctrs_error_subscript_type>
       Error in `vec_slice()`:
-      ! Must subset elements with a valid subscript vector.
+      ! Can't subset elements with `i`.
       x `i` must be logical, numeric, or character, not an environment.
 
 # list_sizes() reports error context

tests/testthat/_snaps/slice-assign.md

@@ -16,7 +16,7 @@
     Output
       <error/vctrs_error_subscript_size>
       Error:
-      ! Must assign to elements with a valid subscript vector.
+      ! Can't assign elements.
       x Logical subscript must be size 1 or 2, not 3.
 
 ---
@@ -27,7 +27,7 @@
     Output
       <error/vctrs_error_subscript_size>
       Error:
-      ! Must assign to elements with a valid subscript vector.
+      ! Can't assign elements.
       x Logical subscript must be size 1 or 32, not 2.
 
 # must assign existing elements
@@ -72,7 +72,7 @@
     Output
       <error/vctrs_error_subscript_type>
       Error:
-      ! Must assign to elements with a valid subscript vector.
+      ! Can't assign elements.
       x Negative and positive locations can't be mixed.
       i Subscript has a positive value at location 2.
     Code
@@ -81,7 +81,7 @@
     Output
       <error/vctrs_error_subscript_type>
       Error:
-      ! Must assign to elements with a valid subscript vector.
+      ! Can't assign elements.
       x Negative locations can't have missing values.
       i Subscript has a missing value at location 2.
 

tests/testthat/_snaps/slice-chop.md

@@ -158,7 +158,7 @@
     Output
       <error/vctrs_error_subscript_type>
       Error:
-      ! Must subset elements with a valid subscript vector.
+      ! Can't subset elements.
       x Subscript can't contain `0` values.
       i It has a `0` value at location 1.
     Code
@@ -167,7 +167,7 @@
     Output
       <error/vctrs_error_subscript_type>
       Error:
-      ! Must subset elements with a valid subscript vector.
+      ! Can't subset elements.
       x Subscript can't contain negative locations.
 
 # list_unchop() fails with complex foreign S3 classes
@@ -298,15 +298,15 @@
     Output
       <error/vctrs_error_subscript_type>
       Error:
-      ! Must subset elements with a valid subscript vector.
+      ! Can't subset elements.
       x Subscript must be numeric, not the string "x".
     Code
       (expect_error(list_unchop(list(1), indices = list(foobar(1L))), class = "vctrs_error_subscript_type")
       )
     Output
       <error/vctrs_error_subscript_type>
       Error:
-      ! Must subset elements with a valid subscript vector.
+      ! Can't subset elements.
       x Subscript must be numeric, not a <vctrs_foobar> object.
 
 # can ignore names in `list_unchop()` by providing a `zap()` name-spec (#232)

tests/testthat/_snaps/slice.md

@@ -5,15 +5,15 @@
     Output
       <error/vctrs_error_subscript_type>
       Error in `vec_slice()`:
-      ! Must subset elements with a valid subscript vector.
+      ! Can't subset elements with `i`.
       x `i` must be logical, numeric, or character, not a <Date> object.
     Code
       (expect_error(vec_slice(1:3, matrix(TRUE, nrow = 1)), class = "vctrs_error_subscript_type")
       )
     Output
       <error/vctrs_error_subscript_type>
       Error in `vec_slice()`:
-      ! Must subset elements with a valid subscript vector.
+      ! Can't subset elements with `i`.
       x Subscript `i` must be a simple vector, not a matrix.
 
 # can't index beyond the end of a vector
@@ -42,7 +42,7 @@
     Output
       <error/vctrs_error_subscript_type>
       Error:
-      ! Must subset elements with a valid subscript vector.
+      ! Can't subset elements with `2^31`.
       x Can't convert from `2^31` <double> to <integer> due to loss of precision.
 
 # Unnamed vector with character subscript is caught
@@ -59,7 +59,7 @@
       vec_slice(1:3, -c(1L, NA))
     Condition
       Error in `vec_slice()`:
-      ! Must subset elements with a valid subscript vector.
+      ! Can't subset elements with `i`.
       x Negative locations can't have missing values.
       i Subscript `i` has a missing value at location 2.
 
@@ -69,7 +69,7 @@
       vec_slice(1:3, c(-1L, 1L))
     Condition
       Error in `vec_slice()`:
-      ! Must subset elements with a valid subscript vector.
+      ! Can't subset elements with `i`.
       x Negative and positive locations can't be mixed.
       i Subscript `i` has a positive value at location 2.