diff --git a/src/expr.rs b/src/expr.rs
index eaa7b362b7d..85ea41fb060 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -8,9 +8,9 @@
// option. This file may not be copied, modified, or distributed
// except according to those terms.
-use visitor::FmtVisitor;
use utils::*;
use lists::{write_list, ListFormatting, SeparatorTactic, ListTactic};
+use rewrite::{Rewrite, RewriteContext};
use syntax::{ast, ptr};
use syntax::codemap::{Pos, Span};
@@ -19,194 +19,239 @@ use syntax::print::pprust;
use MIN_STRING;
-impl<'a> FmtVisitor<'a> {
- fn rewrite_string_lit(&mut self, s: &str, span: Span, width: usize, offset: usize) -> String {
- // FIXME I bet this stomps unicode escapes in the source string
-
- // Check if there is anything to fix: we always try to fixup multi-line
- // strings, or if the string is too long for the line.
- let l_loc = self.codemap.lookup_char_pos(span.lo);
- let r_loc = self.codemap.lookup_char_pos(span.hi);
- if l_loc.line == r_loc.line && r_loc.col.to_usize() <= config!(max_width) {
- return self.snippet(span);
- }
-
- // TODO if lo.col > IDEAL - 10, start a new line (need cur indent for that)
-
- let s = s.escape_default();
-
- let offset = offset + 1;
- let indent = make_indent(offset);
- let indent = &indent;
-
- let mut cur_start = 0;
- let mut result = String::with_capacity(round_up_to_power_of_two(s.len()));
- result.push('"');
- loop {
- let max_chars = if cur_start == 0 {
- // First line.
- width - 2 // 2 = " + \
- } else {
- config!(max_width) - offset - 1 // 1 = either \ or ;
- };
-
- let mut cur_end = cur_start + max_chars;
-
- if cur_end >= s.len() {
- result.push_str(&s[cur_start..]);
- break;
- }
-
- // Make sure we're on a char boundary.
- cur_end = next_char(&s, cur_end);
-
- // Push cur_end left until we reach whitespace
- while !s.char_at(cur_end-1).is_whitespace() {
- cur_end = prev_char(&s, cur_end);
-
- if cur_end - cur_start < MIN_STRING {
- // We can't break at whitespace, fall back to splitting
- // anywhere that doesn't break an escape sequence
- cur_end = next_char(&s, cur_start + max_chars);
- while s.char_at(prev_char(&s, cur_end)) == '\\' {
- cur_end = prev_char(&s, cur_end);
+impl Rewrite for ast::Expr {
+ fn rewrite(&self, context: &RewriteContext, width: usize, offset: usize) -> Option<String> {
+ match self.node {
+ ast::Expr_::ExprLit(ref l) => {
+ match l.node {
+ ast::Lit_::LitStr(ref is, _) => {
+ let result = rewrite_string_lit(context, &is, l.span, width, offset);
+ debug!("string lit: `{:?}`", result);
+ return result;
}
- break;
+ _ => {}
}
}
- // Make sure there is no whitespace to the right of the break.
- while cur_end < s.len() && s.char_at(cur_end).is_whitespace() {
- cur_end = next_char(&s, cur_end+1);
+ ast::Expr_::ExprCall(ref callee, ref args) => {
+ return rewrite_call(context, callee, args, width, offset);
}
- result.push_str(&s[cur_start..cur_end]);
- result.push_str("\\\n");
- result.push_str(indent);
-
- cur_start = cur_end;
+ ast::Expr_::ExprParen(ref subexpr) => {
+ return rewrite_paren(context, subexpr, width, offset);
+ }
+ ast::Expr_::ExprStruct(ref path, ref fields, ref base) => {
+ return rewrite_struct_lit(context, path,
+ fields,
+ base.as_ref().map(|e| &**e),
+ width,
+ offset);
+ }
+ ast::Expr_::ExprTup(ref items) => {
+ return rewrite_tuple_lit(context, items, width, offset);
+ }
+ _ => {}
}
- result.push('"');
- result
+ context.codemap.span_to_snippet(self.span).ok()
+ }
+}
+
+fn rewrite_string_lit(context: &RewriteContext, s: &str, span: Span, width: usize, offset: usize) -> Option<String> {
+ // FIXME I bet this stomps unicode escapes in the source string
+
+ // Check if there is anything to fix: we always try to fixup multi-line
+ // strings, or if the string is too long for the line.
+ let l_loc = context.codemap.lookup_char_pos(span.lo);
+ let r_loc = context.codemap.lookup_char_pos(span.hi);
+ if l_loc.line == r_loc.line && r_loc.col.to_usize() <= config!(max_width) {
+ return context.codemap.span_to_snippet(span).ok();
}
- fn rewrite_call(&mut self,
- callee: &ast::Expr,
- args: &[ptr::P<ast::Expr>],
- width: usize,
- offset: usize)
- -> String
- {
- debug!("rewrite_call, width: {}, offset: {}", width, offset);
+ // TODO if lo.col > IDEAL - 10, start a new line (need cur indent for that)
- // TODO using byte lens instead of char lens (and probably all over the place too)
- let callee_str = self.rewrite_expr(callee, width, offset);
- debug!("rewrite_call, callee_str: `{}`", callee_str);
- // 2 is for parens.
- let remaining_width = width - callee_str.len() - 2;
- let offset = callee_str.len() + 1 + offset;
- let arg_count = args.len();
+ let s = s.escape_default();
- let args_str = if arg_count > 0 {
- let args: Vec<_> = args.iter().map(|e| (self.rewrite_expr(e,
- remaining_width,
- offset), String::new())).collect();
- let fmt = ListFormatting {
- tactic: ListTactic::HorizontalVertical,
- separator: ",",
- trailing_separator: SeparatorTactic::Never,
- indent: offset,
- h_width: remaining_width,
- v_width: remaining_width,
- };
- write_list(&args, &fmt)
+ let offset = offset + 1;
+ let indent = make_indent(offset);
+ let indent = &indent;
+
+ let mut cur_start = 0;
+ let mut result = String::with_capacity(round_up_to_power_of_two(s.len()));
+ result.push('"');
+ loop {
+ let max_chars = if cur_start == 0 {
+ // First line.
+ width - 2 // 2 = " + \
} else {
- String::new()
+ config!(max_width) - offset - 1 // 1 = either \ or ;
};
- format!("{}({})", callee_str, args_str)
- }
+ let mut cur_end = cur_start + max_chars;
- fn rewrite_paren(&mut self, subexpr: &ast::Expr, width: usize, offset: usize) -> String {
- debug!("rewrite_paren, width: {}, offset: {}", width, offset);
- // 1 is for opening paren, 2 is for opening+closing, we want to keep the closing
- // paren on the same line as the subexpr
- let subexpr_str = self.rewrite_expr(subexpr, width-2, offset+1);
- debug!("rewrite_paren, subexpr_str: `{}`", subexpr_str);
- format!("({})", subexpr_str)
- }
-
- fn rewrite_struct_lit(&mut self,
- path: &ast::Path,
- fields: &[ast::Field],
- base: Option<&ast::Expr>,
- width: usize,
- offset: usize)
- -> String
- {
- debug!("rewrite_struct_lit: width {}, offset {}", width, offset);
- assert!(fields.len() > 0 || base.is_some());
-
- let path_str = pprust::path_to_string(path);
- // Foo { a: Foo } - indent is +3, width is -5.
- let indent = offset + path_str.len() + 3;
- let budget = width - (path_str.len() + 5);
-
- let mut field_strs: Vec<_> =
- fields.iter().map(|f| self.rewrite_field(f, budget, indent)).collect();
- if let Some(expr) = base {
- // Another 2 on the width/indent for the ..
- field_strs.push(format!("..{}", self.rewrite_expr(expr, budget - 2, indent + 2)))
+ if cur_end >= s.len() {
+ result.push_str(&s[cur_start..]);
+ break;
}
- // FIXME comments
- let field_strs: Vec<_> = field_strs.into_iter().map(|s| (s, String::new())).collect();
+ // Make sure we're on a char boundary.
+ cur_end = next_char(&s, cur_end);
+
+ // Push cur_end left until we reach whitespace
+ while !s.char_at(cur_end-1).is_whitespace() {
+ cur_end = prev_char(&s, cur_end);
+
+ if cur_end - cur_start < MIN_STRING {
+ // We can't break at whitespace, fall back to splitting
+ // anywhere that doesn't break an escape sequence
+ cur_end = next_char(&s, cur_start + max_chars);
+ while s.char_at(prev_char(&s, cur_end)) == '\\' {
+ cur_end = prev_char(&s, cur_end);
+ }
+ break;
+ }
+ }
+ // Make sure there is no whitespace to the right of the break.
+ while cur_end < s.len() && s.char_at(cur_end).is_whitespace() {
+ cur_end = next_char(&s, cur_end+1);
+ }
+ result.push_str(&s[cur_start..cur_end]);
+ result.push_str("\\\n");
+ result.push_str(indent);
+
+ cur_start = cur_end;
+ }
+ result.push('"');
+
+ Some(result)
+}
+
+fn rewrite_call(context: &RewriteContext,
+ callee: &ast::Expr,
+ args: &[ptr::P<ast::Expr>],
+ width: usize,
+ offset: usize)
+ -> Option<String>
+{
+ debug!("rewrite_call, width: {}, offset: {}", width, offset);
+
+ // TODO using byte lens instead of char lens (and probably all over the place too)
+ let callee_str = try_opt!(callee.rewrite(context, width, offset));
+ debug!("rewrite_call, callee_str: `{:?}`", callee_str);
+ // 2 is for parens.
+ let remaining_width = width - callee_str.len() - 2;
+ let offset = callee_str.len() + 1 + offset;
+ let arg_count = args.len();
+
+ let args_str = if arg_count > 0 {
+ let args_rewritten: Vec<_> =
+ try_opt!(args.iter()
+ .map(|arg| arg.rewrite(context, remaining_width, offset)
+ .map(|arg_str| (arg_str, String::new())))
+ .collect());
let fmt = ListFormatting {
tactic: ListTactic::HorizontalVertical,
separator: ",",
- trailing_separator: if base.is_some() {
- SeparatorTactic::Never
- } else {
- config!(struct_lit_trailing_comma)
- },
- indent: indent,
- h_width: budget,
- v_width: budget,
+ trailing_separator: SeparatorTactic::Never,
+ indent: offset,
+ h_width: remaining_width,
+ v_width: remaining_width,
};
- let fields_str = write_list(&field_strs, &fmt);
- format!("{} {{ {} }}", path_str, fields_str)
+ write_list(&args_rewritten, &fmt)
+ } else {
+ String::new()
+ };
+
+ Some(format!("{}({})", callee_str, args_str))
+}
+
+fn rewrite_paren(context: &RewriteContext, subexpr: &ast::Expr, width: usize, offset: usize) -> Option<String> {
+ debug!("rewrite_paren, width: {}, offset: {}", width, offset);
+ // 1 is for opening paren, 2 is for opening+closing, we want to keep the closing
+ // paren on the same line as the subexpr
+ let subexpr_str = subexpr.rewrite(context, width-2, offset+1);
+ debug!("rewrite_paren, subexpr_str: `{:?}`", subexpr_str);
+ subexpr_str.map(|s| format!("({})", s))
+}
+
+fn rewrite_struct_lit(context: &RewriteContext,
+ path: &ast::Path,
+ fields: &[ast::Field],
+ base: Option<&ast::Expr>,
+ width: usize,
+ offset: usize)
+ -> Option<String>
+{
+ debug!("rewrite_struct_lit: width {}, offset {}", width, offset);
+ assert!(fields.len() > 0 || base.is_some());
+
+ let path_str = pprust::path_to_string(path);
+ // Foo { a: Foo } - indent is +3, width is -5.
+ let indent = offset + path_str.len() + 3;
+ let budget = width - (path_str.len() + 5);
+
+ let field_strs: Vec<_> =
+ try_opt!(fields.iter()
+ .map(|field| rewrite_field(context, field, budget, indent))
+ .chain(base.iter()
+ .map(|expr| expr.rewrite(context,
+ // 2 = ".."
+ budget - 2,
+ indent + 2)
+ .map(|s| format!("..{}", s))))
+ .collect());
+ // FIXME comments
+ let field_strs: Vec<_> = field_strs.into_iter().map(|s| (s, String::new())).collect();
+ let fmt = ListFormatting {
+ tactic: ListTactic::HorizontalVertical,
+ separator: ",",
+ trailing_separator: if base.is_some() {
+ SeparatorTactic::Never
+ } else {
+ config!(struct_lit_trailing_comma)
+ },
+ indent: indent,
+ h_width: budget,
+ v_width: budget,
+ };
+ let fields_str = write_list(&field_strs, &fmt);
+ Some(format!("{} {{ {} }}", path_str, fields_str))
// FIXME if the usual multi-line layout is too wide, we should fall back to
// Foo {
// a: ...,
// }
- }
+}
- fn rewrite_field(&mut self, field: &ast::Field, width: usize, offset: usize) -> String {
- let name = &token::get_ident(field.ident.node);
- let overhead = name.len() + 2;
- let expr = self.rewrite_expr(&field.expr, width - overhead, offset + overhead);
- format!("{}: {}", name, expr)
- }
+fn rewrite_field(context: &RewriteContext, field: &ast::Field, width: usize, offset: usize) -> Option<String> {
+ let name = &token::get_ident(field.ident.node);
+ let overhead = name.len() + 2;
+ let expr = field.expr.rewrite(context, width - overhead, offset + overhead);
+ expr.map(|s| format!("{}: {}", name, s))
+}
- fn rewrite_tuple_lit(&mut self, items: &[ptr::P<ast::Expr>], width: usize, offset: usize)
- -> String {
+fn rewrite_tuple_lit(context: &RewriteContext,
+ items: &[ptr::P<ast::Expr>],
+ width: usize,
+ offset: usize)
+ -> Option<String> {
// opening paren
let indent = offset + 1;
// In case of length 1, need a trailing comma
if items.len() == 1 {
- return format!("({},)", self.rewrite_expr(&*items[0], width - 3, indent));
+ return items[0].rewrite(context, width - 3, indent).map(|s| format!("({},)", s));
}
// Only last line has width-1 as budget, other may take max_width
let item_strs: Vec<_> =
- items.iter()
- .enumerate()
- .map(|(i, item)| self.rewrite_expr(
- item,
- // last line : given width (minus "("+")"), other lines : max_width
- // (minus "("+","))
- if i == items.len() - 1 { width - 2 } else { config!(max_width) - indent - 2 },
- indent))
- .collect();
+ try_opt!(items.iter()
+ .enumerate()
+ .map(|(i, item)| {
+ let rem_width = if i == items.len() - 1 {
+ width - 2
+ } else {
+ config!(max_width) - indent - 2
+ };
+ item.rewrite(context, rem_width, indent)
+ })
+ .collect());
let tactics = if item_strs.iter().any(|s| s.contains('\n')) {
ListTactic::Vertical
} else {
@@ -223,41 +268,5 @@ impl<'a> FmtVisitor<'a> {
v_width: width - 2,
};
let item_str = write_list(&item_strs, &fmt);
- format!("({})", item_str)
+ Some(format!("({})", item_str))
}
-
-
- pub fn rewrite_expr(&mut self, expr: &ast::Expr, width: usize, offset: usize) -> String {
- match expr.node {
- ast::Expr_::ExprLit(ref l) => {
- match l.node {
- ast::Lit_::LitStr(ref is, _) => {
- let result = self.rewrite_string_lit(&is, l.span, width, offset);
- debug!("string lit: `{}`", result);
- return result;
- }
- _ => {}
- }
- }
- ast::Expr_::ExprCall(ref callee, ref args) => {
- return self.rewrite_call(callee, args, width, offset);
- }
- ast::Expr_::ExprParen(ref subexpr) => {
- return self.rewrite_paren(subexpr, width, offset);
- }
- ast::Expr_::ExprStruct(ref path, ref fields, ref base) => {
- return self.rewrite_struct_lit(path,
- fields,
- base.as_ref().map(|e| &**e),
- width,
- offset);
- }
- ast::Expr_::ExprTup(ref items) => {
- return self.rewrite_tuple_lit(items, width, offset);
- }
- _ => {}
- }
-
- self.snippet(expr.span)
- }
-}
diff --git a/src/lib.rs b/src/lib.rs
index a07d31bd87d..1b360433e94 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -59,6 +59,7 @@ mod types;
mod expr;
mod imports;
mod issues;
+mod rewrite;
const MIN_STRING: usize = 10;
// When we get scoped annotations, we should have rustfmt::skip.
diff --git a/src/rewrite.rs b/src/rewrite.rs
new file mode 100644
index 00000000000..354e9b17061
--- /dev/null
+++ b/src/rewrite.rs
@@ -0,0 +1,28 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// A generic trait to abstract the rewriting of an element (of the AST).
+
+use syntax::codemap::CodeMap;
+
+pub trait Rewrite {
+ /// Rewrite self into offset and width.
+ /// `offset` is the indentation of the first line. The next lines
+ /// should begin with a least `offset` spaces (except backwards
+ /// indentation). The first line should not begin with indentation.
+ /// `width` is the maximum number of characters on the last line
+ /// (excluding offset). The width of other lines is not limited by
+ /// `width`.
+ fn rewrite(&self, context: &RewriteContext, width: usize, offset: usize) -> Option<String>;
+}
+
+pub struct RewriteContext<'a> {
+ pub codemap: &'a CodeMap,
+}
diff --git a/src/utils.rs b/src/utils.rs
index 5bcf16ea36b..795c0d98309 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -159,6 +159,15 @@ macro_rules! impl_enum_decodable {
};
}
+// Same as try!, but for Option
+#[macro_export]
+macro_rules! try_opt {
+ ($expr:expr) => (match $expr {
+ Some(val) => val,
+ None => { return None; }
+ })
+}
+
#[test]
fn power_rounding() {
assert_eq!(0, round_up_to_power_of_two(0));
diff --git a/src/visitor.rs b/src/visitor.rs
index 3c9f3ac1b23..0b9a9cfa46b 100644
--- a/src/visitor.rs
+++ b/src/visitor.rs
@@ -16,6 +16,7 @@ use utils;
use SKIP_ANNOTATION;
use changes::ChangeSet;
+use rewrite::{Rewrite, RewriteContext};
pub struct FmtVisitor<'a> {
pub codemap: &'a CodeMap,
@@ -32,9 +33,15 @@ impl<'a, 'v> visit::Visitor<'v> for FmtVisitor<'a> {
self.codemap.lookup_char_pos(ex.span.hi));
self.format_missing(ex.span.lo);
let offset = self.changes.cur_offset_span(ex.span);
- let new_str = self.rewrite_expr(ex, config!(max_width) - offset, offset);
- self.changes.push_str_span(ex.span, &new_str);
- self.last_pos = ex.span.hi;
+ match ex.rewrite(&RewriteContext { codemap: self.codemap },
+ config!(max_width) - offset,
+ offset) {
+ Some(new_str) => {
+ self.changes.push_str_span(ex.span, &new_str);
+ self.last_pos = ex.span.hi;
+ }
+ None => { self.last_pos = ex.span.lo; }
+ }
}
fn visit_stmt(&mut self, stmt: &'v ast::Stmt) {