From 27d6558964dd9e5704d23a722d3ae8598bd3c13c Mon Sep 17 00:00:00 2001
From: Marcus Klaas <mail@marcusklaas.nl>
Date: Tue, 2 Jun 2015 18:44:33 +0200
Subject: [PATCH] Remove empty list imports
---
src/imports.rs | 15 ++++++++-------
src/visitor.rs | 27 +++++++++++++++++++--------
2 files changed, 27 insertions(+), 15 deletions(-)
diff --git a/src/imports.rs b/src/imports.rs
index cab3fa452e4..586caa76b64 100644
--- a/src/imports.rs
+++ b/src/imports.rs
@@ -15,8 +15,6 @@ use syntax::ast;
use syntax::parse::token;
use syntax::print::pprust;
-
-// TODO remove empty lists (if they're even possible)
// TODO (some day) remove unused imports, expand globs, compress many single imports into a list import
fn rewrite_single_use_list(path_str: String, vpi: ast::PathListItem, vis: &str) -> String {
@@ -40,13 +38,14 @@ fn rewrite_single_use_list(path_str: String, vpi: ast::PathListItem, vis: &str)
impl<'a> FmtVisitor<'a> {
// Basically just pretty prints a multi-item import.
+ // Returns None when the import can be removed.
pub fn rewrite_use_list(&mut self,
block_indent: usize,
one_line_budget: usize, // excluding indentation
multi_line_budget: usize,
path: &ast::Path,
path_list: &[ast::PathListItem],
- visibility: ast::Visibility) -> String {
+ visibility: ast::Visibility) -> Option<String> {
let path_str = pprust::path_to_string(path);
let vis = match visibility {
@@ -54,8 +53,10 @@ impl<'a> FmtVisitor<'a> {
_ => ""
};
- if path_list.len() == 1 {
- return rewrite_single_use_list(path_str, path_list[0], vis);
+ match path_list.len() {
+ 0 => return None,
+ 1 => return Some(rewrite_single_use_list(path_str, path_list[0], vis)),
+ _ => ()
}
// 2 = ::
@@ -110,10 +111,10 @@ impl<'a> FmtVisitor<'a> {
ast::PathListItem_::PathListMod{ .. } => None,
}
})).collect();
- if path_str.len() == 0 {
+ Some(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/visitor.rs b/src/visitor.rs
index c15b3c34af0..630638e7bda 100644
--- a/src/visitor.rs
+++ b/src/visitor.rs
@@ -152,19 +152,30 @@ impl<'a, 'v> visit::Visitor<'v> for FmtVisitor<'a> {
match item.node {
ast::Item_::ItemUse(ref vp) => {
- self.format_missing_with_indent(item.span.lo);
match vp.node {
ast::ViewPath_::ViewPathList(ref path, ref path_list) => {
let block_indent = self.block_indent;
let one_line_budget = config!(max_width) - block_indent;
let multi_line_budget = config!(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);
+ let formatted = self.rewrite_use_list(block_indent,
+ one_line_budget,
+ multi_line_budget,
+ path,
+ path_list,
+ item.vis);
+
+ if let Some(new_str) = formatted {
+ self.format_missing_with_indent(item.span.lo);
+ self.changes.push_str_span(item.span, &new_str);
+ } else {
+ // Format up to last newline
+ let span = codemap::mk_sp(self.last_pos, item.span.lo);
+ let span_end = match self.snippet(span).rfind('\n') {
+ Some(offset) => self.last_pos + BytePos(offset as u32),
+ None => item.span.lo
+ };
+ self.format_missing(span_end);
+ }
self.last_pos = item.span.hi;
}
ast::ViewPath_::ViewPathGlob(_) => {