]> git.lizzy.rs Git - rust.git/blobdiff - src/closures.rs
Fixup formatting
[rust.git] / src / closures.rs
index b9009598f1a527527a32d472ddacbc203c163c7b..fa656cc351eea68c857d6bbe8ce99cdd3acaa384 100644 (file)
@@ -8,17 +8,18 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use syntax::{ast, ptr};
-use syntax::codemap::Span;
+use config::lists::*;
 use syntax::parse::classify;
+use syntax::source_map::Span;
+use syntax::{ast, ptr};
 
-use codemap::SpanUtils;
-use expr::{block_contains_comment, is_simple_block, is_unsafe_block, rewrite_cond, ToExpr};
+use expr::{block_contains_comment, is_simple_block, is_unsafe_block, rewrite_cond};
 use items::{span_hi_for_arg, span_lo_for_arg};
-use lists::{definitive_tactic, itemize_list, write_list, DefinitiveListTactic, ListFormatting,
-            ListTactic, Separator, SeparatorPlace, SeparatorTactic};
+use lists::{definitive_tactic, itemize_list, write_list, ListFormatting, Separator};
+use overflow::OverflowableItem;
 use rewrite::{Rewrite, RewriteContext};
 use shape::Shape;
+use source_map::SpanUtils;
 use utils::{last_line_width, left_most_sub_expr, stmt_expr};
 
 // This module is pretty messy because of the rules around closures and blocks:
@@ -33,6 +34,8 @@
 
 pub fn rewrite_closure(
     capture: ast::CaptureBy,
+    asyncness: ast::IsAsync,
+    movability: ast::Movability,
     fn_decl: &ast::FnDecl,
     body: &ast::Expr,
     span: Span,
@@ -41,15 +44,18 @@ pub fn rewrite_closure(
 ) -> Option<String> {
     debug!("rewrite_closure {:?}", body);
 
-    let (prefix, extra_offset) =
-        rewrite_closure_fn_decl(capture, fn_decl, body, span, context, shape)?;
+    let (prefix, extra_offset) = rewrite_closure_fn_decl(
+        capture, asyncness, movability, fn_decl, body, span, context, shape,
+    )?;
     // 1 = space between `|...|` and body.
     let body_shape = shape.offset_left(extra_offset)?;
 
-    if let ast::ExprKind::Block(ref block) = body.node {
+    if let ast::ExprKind::Block(ref block, _) = body.node {
         // The body of the closure is an empty block.
-        if block.stmts.is_empty() && !block_contains_comment(block, context.codemap) {
-            return Some(format!("{} {{}}", prefix));
+        if block.stmts.is_empty() && !block_contains_comment(block, context.source_map) {
+            return body
+                .rewrite(context, shape)
+                .map(|s| format!("{} {}", prefix, s));
         }
 
         let result = match fn_decl.output {
@@ -93,7 +99,7 @@ fn get_inner_expr<'a>(
     prefix: &str,
     context: &RewriteContext,
 ) -> &'a ast::Expr {
-    if let ast::ExprKind::Block(ref block) = expr.node {
+    if let ast::ExprKind::Block(ref block, _) = expr.node {
         if !needs_block(block, prefix, context) {
             // block.stmts.len() == 1
             if let Some(expr) = stmt_expr(&block.stmts[0]) {
@@ -107,8 +113,26 @@ fn get_inner_expr<'a>(
 
 // Figure out if a block is necessary.
 fn needs_block(block: &ast::Block, prefix: &str, context: &RewriteContext) -> bool {
-    is_unsafe_block(block) || block.stmts.len() > 1
-        || block_contains_comment(block, context.codemap) || prefix.contains('\n')
+    is_unsafe_block(block)
+        || block.stmts.len() > 1
+        || block_contains_comment(block, context.source_map)
+        || prefix.contains('\n')
+}
+
+fn veto_block(e: &ast::Expr) -> bool {
+    match e.node {
+        ast::ExprKind::Call(..)
+        | ast::ExprKind::Binary(..)
+        | ast::ExprKind::Cast(..)
+        | ast::ExprKind::Type(..)
+        | ast::ExprKind::Assign(..)
+        | ast::ExprKind::AssignOp(..)
+        | ast::ExprKind::Field(..)
+        | ast::ExprKind::Index(..)
+        | ast::ExprKind::Range(..)
+        | ast::ExprKind::Try(..) => true,
+        _ => false,
+    }
 }
 
 // Rewrite closure with a single expression wrapping its body with block.
@@ -119,25 +143,23 @@ fn rewrite_closure_with_block(
     shape: Shape,
 ) -> Option<String> {
     let left_most = left_most_sub_expr(body);
-    let veto_block = left_most != body && !classify::expr_requires_semi_to_be_stmt(left_most);
+    let veto_block = veto_block(body) && !classify::expr_requires_semi_to_be_stmt(left_most);
     if veto_block {
         return None;
     }
 
     let block = ast::Block {
-        stmts: vec![
-            ast::Stmt {
-                id: ast::NodeId::new(0),
-                node: ast::StmtKind::Expr(ptr::P(body.clone())),
-                span: body.span,
-            },
-        ],
+        stmts: vec![ast::Stmt {
+            id: ast::NodeId::new(0),
+            node: ast::StmtKind::Expr(ptr::P(body.clone())),
+            span: body.span,
+        }],
         id: ast::NodeId::new(0),
         rules: ast::BlockCheckMode::Default,
         span: body.span,
         recovered: false,
     };
-    let block = ::expr::rewrite_block_with_visitor(context, "", &block, shape, false)?;
+    let block = ::expr::rewrite_block_with_visitor(context, "", &block, None, None, shape, false)?;
     Some(format!("{} {}", prefix, block))
 }
 
@@ -152,7 +174,7 @@ fn allow_multi_line(expr: &ast::Expr) -> bool {
         match expr.node {
             ast::ExprKind::Match(..)
             | ast::ExprKind::Block(..)
-            | ast::ExprKind::Catch(..)
+            | ast::ExprKind::TryBlock(..)
             | ast::ExprKind::Loop(..)
             | ast::ExprKind::Struct(..) => true,
 
@@ -168,7 +190,7 @@ fn allow_multi_line(expr: &ast::Expr) -> bool {
 
     // When rewriting closure's body without block, we require it to fit in a single line
     // unless it is a block-like expression or we are inside macro call.
-    let veto_multiline = (!allow_multi_line(expr) && !context.inside_macro)
+    let veto_multiline = (!allow_multi_line(expr) && !context.inside_macro())
         || context.config.force_multiline_blocks();
     expr.rewrite(context, shape)
         .and_then(|rw| {
@@ -194,20 +216,30 @@ fn rewrite_closure_block(
 // Return type is (prefix, extra_offset)
 fn rewrite_closure_fn_decl(
     capture: ast::CaptureBy,
+    asyncness: ast::IsAsync,
+    movability: ast::Movability,
     fn_decl: &ast::FnDecl,
     body: &ast::Expr,
     span: Span,
     context: &RewriteContext,
     shape: Shape,
 ) -> Option<(String, usize)> {
+    let is_async = if asyncness.is_async() { "async " } else { "" };
     let mover = if capture == ast::CaptureBy::Value {
         "move "
     } else {
         ""
     };
+    let immovable = if movability == ast::Movability::Static {
+        "static "
+    } else {
+        ""
+    };
     // 4 = "|| {".len(), which is overconservative when the closure consists of
     // a single expression.
-    let nested_shape = shape.shrink_left(mover.len())?.sub_width(4)?;
+    let nested_shape = shape
+        .shrink_left(is_async.len() + mover.len() + immovable.len())?
+        .sub_width(4)?;
 
     // 1 = |
     let argument_offset = nested_shape.indent + 1;
@@ -215,23 +247,20 @@ fn rewrite_closure_fn_decl(
     let ret_str = fn_decl.output.rewrite(context, arg_shape)?;
 
     let arg_items = itemize_list(
-        context.codemap,
+        context.snippet_provider,
         fn_decl.inputs.iter(),
         "|",
         ",",
         |arg| span_lo_for_arg(arg),
         |arg| span_hi_for_arg(context, arg),
         |arg| arg.rewrite(context, arg_shape),
-        context.codemap.span_after(span, "|"),
+        context.snippet_provider.span_after(span, "|"),
         body.span.lo(),
         false,
     );
     let item_vec = arg_items.collect::<Vec<_>>();
     // 1 = space between arguments and return type.
-    let horizontal_budget = nested_shape
-        .width
-        .checked_sub(ret_str.len() + 1)
-        .unwrap_or(0);
+    let horizontal_budget = nested_shape.width.saturating_sub(ret_str.len() + 1);
     let tactic = definitive_tactic(
         &item_vec,
         ListTactic::HorizontalVertical,
@@ -243,18 +272,11 @@ fn rewrite_closure_fn_decl(
         _ => arg_shape,
     };
 
-    let fmt = ListFormatting {
-        tactic: tactic,
-        separator: ",",
-        trailing_separator: SeparatorTactic::Never,
-        separator_place: SeparatorPlace::Back,
-        shape: arg_shape,
-        ends_with_newline: false,
-        preserve_newline: true,
-        config: context.config,
-    };
+    let fmt = ListFormatting::new(arg_shape, context.config)
+        .tactic(tactic)
+        .preserve_newline(true);
     let list_str = write_list(&item_vec, &fmt)?;
-    let mut prefix = format!("{}|{}|", mover, list_str);
+    let mut prefix = format!("{}{}{}|{}|", is_async, immovable, mover, list_str);
 
     if !ret_str.is_empty() {
         if prefix.contains('\n') {
@@ -278,17 +300,21 @@ pub fn rewrite_last_closure(
     expr: &ast::Expr,
     shape: Shape,
 ) -> Option<String> {
-    if let ast::ExprKind::Closure(capture, _, ref fn_decl, ref body, _) = expr.node {
+    if let ast::ExprKind::Closure(capture, asyncness, movability, ref fn_decl, ref body, _) =
+        expr.node
+    {
         let body = match body.node {
-            ast::ExprKind::Block(ref block)
-                if !is_unsafe_block(block) && is_simple_block(block, context.codemap) =>
+            ast::ExprKind::Block(ref block, _)
+                if !is_unsafe_block(block)
+                    && is_simple_block(block, Some(&body.attrs), context.source_map) =>
             {
                 stmt_expr(&block.stmts[0]).unwrap_or(body)
             }
             _ => body,
         };
-        let (prefix, extra_offset) =
-            rewrite_closure_fn_decl(capture, fn_decl, body, expr.span, context, shape)?;
+        let (prefix, extra_offset) = rewrite_closure_fn_decl(
+            capture, asyncness, movability, fn_decl, body, expr.span, context, shape,
+        )?;
         // If the closure goes multi line before its body, do not overflow the closure.
         if prefix.contains('\n') {
             return None;
@@ -319,9 +345,9 @@ pub fn rewrite_last_closure(
 
         // When overflowing the closure which consists of a single control flow expression,
         // force to use block if its condition uses multi line.
-        let is_multi_lined_cond = rewrite_cond(context, body, body_shape)
-            .map(|cond| cond.contains('\n') || cond.len() > body_shape.width)
-            .unwrap_or(false);
+        let is_multi_lined_cond = rewrite_cond(context, body, body_shape).map_or(false, |cond| {
+            cond.contains('\n') || cond.len() > body_shape.width
+        });
         if is_multi_lined_cond {
             return rewrite_closure_with_block(body, &prefix, context, body_shape);
         }
@@ -333,25 +359,20 @@ pub fn rewrite_last_closure(
 }
 
 /// Returns true if the given vector of arguments has more than one `ast::ExprKind::Closure`.
-pub fn args_have_many_closure<T>(args: &[&T]) -> bool
-where
-    T: ToExpr,
-{
+pub fn args_have_many_closure(args: &[OverflowableItem]) -> bool {
     args.iter()
-        .filter(|arg| {
-            arg.to_expr()
-                .map(|e| match e.node {
-                    ast::ExprKind::Closure(..) => true,
-                    _ => false,
-                })
-                .unwrap_or(false)
+        .filter_map(|arg| arg.to_expr())
+        .filter(|expr| match expr.node {
+            ast::ExprKind::Closure(..) => true,
+            _ => false,
         })
-        .count() > 1
+        .count()
+        > 1
 }
 
 fn is_block_closure_forced(context: &RewriteContext, expr: &ast::Expr) -> bool {
     // If we are inside macro, we do not want to add or remove block from closure body.
-    if context.inside_macro {
+    if context.inside_macro() {
         false
     } else {
         is_block_closure_forced_inner(expr)