Add `short_item_threshold` config option
Allow custom short item threshold values via config
diff --git a/Configurations.md b/Configurations.md
index ecec97d..a47439b 100644
--- a/Configurations.md
+++ b/Configurations.md
@@ -2200,6 +2200,40 @@
- **Possible values**: any published version (e.g. `"0.3.8"`)
- **Stable**: No (tracking issue: [#3386](https://github.com/rust-lang/rustfmt/issues/3386))
+## `short_array_element_width_threshold`
+
+The width threshold for an array element to be considered "short".
+
+The layout of an array is dependent on the length of each of its elements.
+If the length of every element in an array is below this threshold (all elements are "short") then the array can be formatted in the mixed/compressed style, but if any one element has a length that exceeds this threshold then the array elements will have to be formatted vertically.
+
+- **Default value**: `10`
+- **Possible values**: any positive integer that is less than or equal to the value specified for [`max_width`](#max_width)
+- **Stable**: Yes
+
+#### `10` (default):
+```rust
+fn main() {
+ pub const FORMAT_TEST: [u64; 5] = [
+ 0x0000000000000000,
+ 0xaaaaaaaaaaaaaaaa,
+ 0xbbbbbbbbbbbbbbbb,
+ 0xcccccccccccccccc,
+ 0xdddddddddddddddd,
+ ];
+}
+```
+#### `20`:
+```rust
+fn main() {
+ pub const FORMAT_TEST: [u64; 5] = [
+ 0x0000000000000000, 0xaaaaaaaaaaaaaaaa, 0xbbbbbbbbbbbbbbbb, 0xcccccccccccccccc,
+ 0xdddddddddddddddd,
+ ];
+}
+```
+See also [`max_width`](#max_width).
+
## `skip_children`
Don't reformat out of line modules
diff --git a/src/config/mod.rs b/src/config/mod.rs
index 5041e1e..18e1854 100644
--- a/src/config/mod.rs
+++ b/src/config/mod.rs
@@ -106,6 +106,8 @@
// Misc.
remove_nested_parens: bool, true, true, "Remove nested parens";
combine_control_expr: bool, true, false, "Combine control expressions with function calls";
+ short_array_element_width_threshold: usize, 10, true,
+ "Width threshold for an array element to be considered short";
overflow_delimited_expr: bool, false, false,
"Allow trailing bracket/brace delimited expressions to overflow";
struct_field_align_threshold: usize, 0, false,
@@ -591,6 +593,7 @@
binop_separator = "Front"
remove_nested_parens = true
combine_control_expr = true
+short_array_element_width_threshold = 10
overflow_delimited_expr = false
struct_field_align_threshold = 0
enum_discrim_align_threshold = 0
diff --git a/src/overflow.rs b/src/overflow.rs
index 3475f5c..80aed99 100644
--- a/src/overflow.rs
+++ b/src/overflow.rs
@@ -26,8 +26,6 @@
use crate::types::{can_be_overflowed_type, SegmentParam};
use crate::utils::{count_newlines, extra_offset, first_line_width, last_line_width, mk_sp};
-const SHORT_ITEM_THRESHOLD: usize = 10;
-
/// A list of `format!`-like macros, that take a long format string and a list of arguments to
/// format.
///
@@ -572,7 +570,12 @@
if one_line {
tactic = DefinitiveListTactic::SpecialMacro(num_args_before);
};
- } else if is_every_expr_simple(&self.items) && no_long_items(list_items) {
+ } else if is_every_expr_simple(&self.items)
+ && no_long_items(
+ list_items,
+ self.context.config.short_array_element_width_threshold(),
+ )
+ {
tactic = DefinitiveListTactic::Mixed;
}
}
@@ -755,9 +758,9 @@
}
}
-fn no_long_items(list: &[ListItem]) -> bool {
+fn no_long_items(list: &[ListItem], short_array_element_width_threshold: usize) -> bool {
list.iter()
- .all(|item| item.inner_as_ref().len() <= SHORT_ITEM_THRESHOLD)
+ .all(|item| item.inner_as_ref().len() <= short_array_element_width_threshold)
}
/// In case special-case style is required, returns an offset from which we start horizontal layout.
diff --git a/tests/source/configs/short_array_element_width_threshold/10.rs b/tests/source/configs/short_array_element_width_threshold/10.rs
new file mode 100644
index 0000000..7d0d709
--- /dev/null
+++ b/tests/source/configs/short_array_element_width_threshold/10.rs
@@ -0,0 +1,11 @@
+// rustfmt-short_array_element_width_threshold: 10
+
+fn main() {
+ pub const FORMAT_TEST: [u64; 5] = [
+ 0x0000000000000000,
+ 0xaaaaaaaaaaaaaaaa,
+ 0xbbbbbbbbbbbbbbbb,
+ 0xcccccccccccccccc,
+ 0xdddddddddddddddd,
+ ];
+}
\ No newline at end of file
diff --git a/tests/source/configs/short_array_element_width_threshold/20.rs b/tests/source/configs/short_array_element_width_threshold/20.rs
new file mode 100644
index 0000000..8a93a51
--- /dev/null
+++ b/tests/source/configs/short_array_element_width_threshold/20.rs
@@ -0,0 +1,11 @@
+// rustfmt-short_array_element_width_threshold: 20
+
+fn main() {
+ pub const FORMAT_TEST: [u64; 5] = [
+ 0x0000000000000000,
+ 0xaaaaaaaaaaaaaaaa,
+ 0xbbbbbbbbbbbbbbbb,
+ 0xcccccccccccccccc,
+ 0xdddddddddddddddd,
+ ];
+}
\ No newline at end of file
diff --git a/tests/source/configs/short_array_element_width_threshold/greater_than_max_width.rs b/tests/source/configs/short_array_element_width_threshold/greater_than_max_width.rs
new file mode 100644
index 0000000..710b6fe
--- /dev/null
+++ b/tests/source/configs/short_array_element_width_threshold/greater_than_max_width.rs
@@ -0,0 +1,12 @@
+// rustfmt-max_width: 20
+// rustfmt-short_array_element_width_threshold: 30
+
+fn main() {
+ pub const FORMAT_TEST: [u64; 5] = [
+ 0x0000000000000000,
+ 0xaaaaaaaaaaaaaaaa,
+ 0xbbbbbbbbbbbbbbbb,
+ 0xcccccccccccccccc,
+ 0xdddddddddddddddd,
+ ];
+}
diff --git a/tests/target/configs/short_array_element_width_threshold/10.rs b/tests/target/configs/short_array_element_width_threshold/10.rs
new file mode 100644
index 0000000..78c4adb
--- /dev/null
+++ b/tests/target/configs/short_array_element_width_threshold/10.rs
@@ -0,0 +1,11 @@
+// rustfmt-short_array_element_width_threshold: 10
+
+fn main() {
+ pub const FORMAT_TEST: [u64; 5] = [
+ 0x0000000000000000,
+ 0xaaaaaaaaaaaaaaaa,
+ 0xbbbbbbbbbbbbbbbb,
+ 0xcccccccccccccccc,
+ 0xdddddddddddddddd,
+ ];
+}
diff --git a/tests/target/configs/short_array_element_width_threshold/20.rs b/tests/target/configs/short_array_element_width_threshold/20.rs
new file mode 100644
index 0000000..6084690
--- /dev/null
+++ b/tests/target/configs/short_array_element_width_threshold/20.rs
@@ -0,0 +1,8 @@
+// rustfmt-short_array_element_width_threshold: 20
+
+fn main() {
+ pub const FORMAT_TEST: [u64; 5] = [
+ 0x0000000000000000, 0xaaaaaaaaaaaaaaaa, 0xbbbbbbbbbbbbbbbb, 0xcccccccccccccccc,
+ 0xdddddddddddddddd,
+ ];
+}
diff --git a/tests/target/configs/short_array_element_width_threshold/greater_than_max_width.rs b/tests/target/configs/short_array_element_width_threshold/greater_than_max_width.rs
new file mode 100644
index 0000000..710b6fe
--- /dev/null
+++ b/tests/target/configs/short_array_element_width_threshold/greater_than_max_width.rs
@@ -0,0 +1,12 @@
+// rustfmt-max_width: 20
+// rustfmt-short_array_element_width_threshold: 30
+
+fn main() {
+ pub const FORMAT_TEST: [u64; 5] = [
+ 0x0000000000000000,
+ 0xaaaaaaaaaaaaaaaa,
+ 0xbbbbbbbbbbbbbbbb,
+ 0xcccccccccccccccc,
+ 0xdddddddddddddddd,
+ ];
+}
