From c790d7d5507118598b7f25cc00e07217046c5f53 Mon Sep 17 00:00:00 2001
From: Marcus Klaas <mail@marcusklaas.nl>
Date: Mon, 4 May 2015 17:16:51 +0200
Subject: [PATCH] Keep import lists on a single line when possible
---
src/imports.rs | 25 ++++++++++++++++---------
src/lists.rs | 16 +++++++++++-----
src/visitor.rs | 19 ++++++++++---------
tests/idem/imports.rs | 14 +++++++-------
4 files changed, 44 insertions(+), 30 deletions(-)
diff --git a/src/imports.rs b/src/imports.rs
index 9cdd89df0cb..9968d8b5315 100644
--- a/src/imports.rs
+++ b/src/imports.rs
@@ -23,10 +23,11 @@ impl<'a> FmtVisitor<'a> {
// Basically just pretty prints a multi-item import.
pub fn rewrite_use_list(&mut self,
block_indent: usize,
- budget: usize, // excluding indentation
+ one_line_budget: usize, // excluding indentation
+ multi_line_budget: usize,
path: &ast::Path,
path_list: &[ast::PathListItem],
- visibility: ast::Visibility) -> Option<String> {
+ visibility: ast::Visibility) -> String {
let path_str = pprust::path_to_string(&path);
let vis = match visibility {
@@ -41,10 +42,16 @@ impl<'a> FmtVisitor<'a> {
// 2 = } + ;
let used_width = indent + 2;
- let remaining_budget = if used_width >= budget {
- return None;
+ // Break as early as possible when we've blown our budget.
+ let remaining_line_budget = if used_width > one_line_budget {
+ 0
} else {
- budget - used_width
+ one_line_budget - used_width
+ };
+ let remaining_multi_budget = if used_width > multi_line_budget {
+ 0
+ } else {
+ multi_line_budget - used_width
};
let fmt = ListFormatting {
@@ -52,8 +59,8 @@ impl<'a> FmtVisitor<'a> {
separator: ",",
trailing_separator: SeparatorTactic::Never,
indent: block_indent + indent,
- h_width: remaining_budget,
- v_width: remaining_budget,
+ h_width: remaining_line_budget,
+ v_width: remaining_multi_budget,
};
// TODO handle any comments inbetween items.
@@ -79,10 +86,10 @@ impl<'a> FmtVisitor<'a> {
ast::PathListItem_::PathListMod{ .. } => None,
}
})).collect();
- Some(if path_str.len() == 0 {
+ if path_str.len() == 0 {
format!("{}use {{{}}};", vis, write_list(&items, &fmt))
} else {
format!("{}use {}::{{{}}};", vis, path_str, write_list(&items, &fmt))
- })
+ }
}
}
diff --git a/src/lists.rs b/src/lists.rs
index 47b6491544d..06fb93f71e1 100644
--- a/src/lists.rs
+++ b/src/lists.rs
@@ -58,18 +58,24 @@ pub fn write_list<'b>(items: &[(String, String)], formatting: &ListFormatting<'b
};
let sep_len = formatting.separator.len();
let total_sep_len = (sep_len + 1) * sep_count;
-
let total_width = calculate_width(items);
+ let fits_single = total_width + total_sep_len <= formatting.h_width;
// Check if we need to fallback from horizontal listing, if possible.
if tactic == ListTactic::HorizontalVertical {
debug!("write_list: total_width: {}, total_sep_len: {}, h_width: {}",
total_width, total_sep_len, formatting.h_width);
- if total_width + total_sep_len > formatting.h_width {
- tactic = ListTactic::Vertical;
+ tactic = if fits_single {
+ ListTactic::Horizontal
} else {
- tactic = ListTactic::Horizontal;
- }
+ ListTactic::Vertical
+ };
+ }
+
+ // Check if we can fit everything on a single line in mixed mode.
+ // The horizontal tactic does not break after v_width columns.
+ if tactic == ListTactic::Mixed && fits_single {
+ tactic = ListTactic::Horizontal;
}
// Now that we know how we will layout, we can decide for sure if there
diff --git a/src/visitor.rs b/src/visitor.rs
index b4fe95c9dd3..55957464ef7 100644
--- a/src/visitor.rs
+++ b/src/visitor.rs
@@ -149,15 +149,16 @@ impl<'a, 'v> visit::Visitor<'v> for FmtVisitor<'a> {
match vp.node {
ast::ViewPath_::ViewPathList(ref path, ref path_list) => {
let block_indent = self.block_indent;
- let budget = IDEAL_WIDTH - block_indent;
- if let Some(new_str) = self.rewrite_use_list(block_indent,
- budget,
- path,
- path_list,
- item.vis) {
- self.changes.push_str_span(item.span, &new_str);
- self.last_pos = item.span.hi;
- }
+ let one_line_budget = MAX_WIDTH - block_indent;
+ let multi_line_budget = IDEAL_WIDTH - block_indent;
+ let new_str = self.rewrite_use_list(block_indent,
+ one_line_budget,
+ multi_line_budget,
+ path,
+ path_list,
+ item.vis);
+ self.changes.push_str_span(item.span, &new_str);
+ self.last_pos = item.span.hi;
}
ast::ViewPath_::ViewPathGlob(_) => {
// FIXME convert to list?
diff --git a/tests/idem/imports.rs b/tests/idem/imports.rs
index 72c4a1fb769..9644c62dde7 100644
--- a/tests/idem/imports.rs
+++ b/tests/idem/imports.rs
@@ -1,20 +1,20 @@
// Imports.
// Long import.
-use syntax::ast::{ItemForeignMod, ItemImpl, ItemMac, ItemMod, ItemStatic,
- ItemDefaultImpl};
+use syntax::ast::{ItemForeignMod, ItemImpl, ItemMac, ItemMod, ItemStatic, ItemDefaultImpl};
+use exceedingly::looooooooooooooooooooooooooooooooooooooooooooooooooooooooooong::import::path::{ItemA,
+ ItemB};
use {Foo, Bar};
use Foo::{Bar, Baz};
-pub use syntax::ast::{Expr_, Expr, ExprAssign, ExprCall, ExprMethodCall,
- ExprPath};
+pub use syntax::ast::{Expr_, Expr, ExprAssign, ExprCall, ExprMethodCall, ExprPath};
mod Foo {
- pub use syntax::ast::{Expr_, ExprEval, ToExpr, ExprMethodCall, ToExprPath};
+ pub use syntax::ast::{ItemForeignMod, ItemImpl, ItemMac, ItemMod, ItemStatic, ItemDefaultImpl};
mod Foo2 {
- pub use syntax::ast::{Expr_, ExprEval, ToExpr, ExprMethodCall,
- ToExprPath};
+ pub use syntax::ast::{ItemForeignMod, ItemImpl, ItemMac, ItemMod,
+ ItemStatic, ItemDefaultImpl};
}
}