2929//! This lint is **warn** by default.
3030use rustc:: lint:: * ;
3131use syntax:: ast;
32- use syntax:: codemap:: { original_sp, DUMMY_SP } ;
32+ use syntax:: codemap:: { original_sp, DUMMY_SP } ;
3333use std:: borrow:: Cow ;
3434
3535use utils:: { in_macro, span_help_and_lint, snippet_block, snippet, trim_multiline} ;
@@ -163,7 +163,7 @@ impl EarlyLintPass for NeedlessContinue {
163163 * // region C
164164 * }
165165 * }
166- */
166+ * * /
167167
168168/// Given an expression, returns true if either of the following is true
169169///
@@ -181,23 +181,27 @@ fn needless_continue_in_else(else_expr: &ast::Expr) -> bool {
181181fn is_first_block_stmt_continue ( block : & ast:: Block ) -> bool {
182182 block. stmts . get ( 0 ) . map_or ( false , |stmt| match stmt. node {
183183 ast:: StmtKind :: Semi ( ref e) |
184- ast:: StmtKind :: Expr ( ref e) => if let ast:: ExprKind :: Continue ( _) = e. node {
185- true
186- } else {
187- false
184+ ast:: StmtKind :: Expr ( ref e) => {
185+ if let ast:: ExprKind :: Continue ( _) = e. node {
186+ true
187+ } else {
188+ false
189+ }
188190 } ,
189191 _ => false ,
190192 } )
191193}
192194
193195/// If `expr` is a loop expression (while/while let/for/loop), calls `func` with
194196/// the AST object representing the loop block of `expr`.
195- fn with_loop_block < F > ( expr : & ast:: Expr , mut func : F ) where F : FnMut ( & ast:: Block ) {
197+ fn with_loop_block < F > ( expr : & ast:: Expr , mut func : F )
198+ where F : FnMut ( & ast:: Block )
199+ {
196200 match expr. node {
197- ast:: ExprKind :: While ( _, ref loop_block, _) |
201+ ast:: ExprKind :: While ( _, ref loop_block, _) |
198202 ast:: ExprKind :: WhileLet ( _, _, ref loop_block, _) |
199- ast:: ExprKind :: ForLoop ( _, _, ref loop_block, _) |
200- ast:: ExprKind :: Loop ( ref loop_block, _) => func ( loop_block) ,
203+ ast:: ExprKind :: ForLoop ( _, _, ref loop_block, _) |
204+ ast:: ExprKind :: Loop ( ref loop_block, _) => func ( loop_block) ,
201205 _ => { } ,
202206 }
203207}
@@ -211,15 +215,16 @@ fn with_loop_block<F>(expr: &ast::Expr, mut func: F) where F: FnMut(&ast::Block)
211215/// - The `else` expression.
212216///
213217fn with_if_expr < F > ( stmt : & ast:: Stmt , mut func : F )
214- where F : FnMut ( & ast:: Expr , & ast:: Expr , & ast:: Block , & ast:: Expr ) {
218+ where F : FnMut ( & ast:: Expr , & ast:: Expr , & ast:: Block , & ast:: Expr )
219+ {
215220 match stmt. node {
216221 ast:: StmtKind :: Semi ( ref e) |
217222 ast:: StmtKind :: Expr ( ref e) => {
218223 if let ast:: ExprKind :: If ( ref cond, ref if_block, Some ( ref else_expr) ) = e. node {
219224 func ( e, cond, if_block, else_expr) ;
220225 }
221226 } ,
222- _ => { } ,
227+ _ => { } ,
223228 }
224229}
225230
@@ -249,45 +254,37 @@ struct LintData<'a> {
249254
250255const MSG_REDUNDANT_ELSE_BLOCK : & ' static str = "This else block is redundant.\n " ;
251256
252- const MSG_ELSE_BLOCK_NOT_NEEDED : & ' static str = "There is no need for an explicit `else` block for this `if` expression\n " ;
257+ const MSG_ELSE_BLOCK_NOT_NEEDED : & ' static str = "There is no need for an explicit `else` block for this `if` \
258+ \n ";
253259
254- const DROP_ELSE_BLOCK_AND_MERGE_MSG : & ' static str =
255- "Consider dropping the else clause and merging the code that follows (in the loop) with the if block, like so:\n ";
260+ const DROP_ELSE_BLOCK_AND_MERGE_MSG : & ' static str = "Consider dropping the else clause and merging the code that \
261+ follows (in the loop) with the if block, like so:\n ";
256262
257- const DROP_ELSE_BLOCK_MSG : & ' static str =
258- "Consider dropping the else clause, and moving out the code in the else block, like so:\n ";
263+ const DROP_ELSE_BLOCK_MSG : & ' static str = "Consider dropping the else clause, and moving out the code in the else \
264+ block, like so:\n ";
259265
260266
261- fn emit_warning < ' a > ( ctx : & EarlyContext ,
262- data : & ' a LintData ,
263- header : & str ,
264- typ : LintType ) {
267+ fn emit_warning < ' a > ( ctx : & EarlyContext , data : & ' a LintData , header : & str , typ : LintType ) {
265268
266269 // snip is the whole *help* message that appears after the warning.
267270 // message is the warning message.
268271 // expr is the expression which the lint warning message refers to.
269272 let ( snip, message, expr) = match typ {
270273 LintType :: ContinueInsideElseBlock => {
271- ( suggestion_snippet_for_continue_inside_else ( ctx, data, header) ,
272- MSG_REDUNDANT_ELSE_BLOCK ,
273- data. else_expr )
274+ ( suggestion_snippet_for_continue_inside_else ( ctx, data, header) , MSG_REDUNDANT_ELSE_BLOCK , data. else_expr )
274275 } ,
275276 LintType :: ContinueInsideThenBlock => {
276- ( suggestion_snippet_for_continue_inside_if ( ctx, data, header) ,
277- MSG_ELSE_BLOCK_NOT_NEEDED ,
278- data. if_expr )
279- }
277+ ( suggestion_snippet_for_continue_inside_if ( ctx, data, header) , MSG_ELSE_BLOCK_NOT_NEEDED , data. if_expr )
278+ } ,
280279 } ;
281280 span_help_and_lint ( ctx, NEEDLESS_CONTINUE , expr. span , message, & snip) ;
282281}
283282
284- fn suggestion_snippet_for_continue_inside_if < ' a > ( ctx : & EarlyContext ,
285- data : & ' a LintData ,
286- header : & str ) -> String {
283+ fn suggestion_snippet_for_continue_inside_if < ' a > ( ctx : & EarlyContext , data : & ' a LintData , header : & str ) -> String {
287284 let cond_code = snippet ( ctx, data. if_cond . span , ".." ) ;
288285
289- let if_code = format ! ( "if {} {{\n continue;\n }}\n " , cond_code) ;
290- /* ^^^^--- Four spaces of indentation. */
286+ let if_code = format ! ( "if {} {{\n continue;\n }}\n " , cond_code) ;
287+ /* ^^^^--- Four spaces of indentation. */
291288 // region B
292289 let else_code = snippet ( ctx, data. else_expr . span , ".." ) . into_owned ( ) ;
293290 let else_code = erode_block ( & else_code) ;
@@ -300,12 +297,9 @@ fn suggestion_snippet_for_continue_inside_if<'a>(ctx: &EarlyContext,
300297 ret
301298}
302299
303- fn suggestion_snippet_for_continue_inside_else < ' a > ( ctx : & EarlyContext ,
304- data : & ' a LintData ,
305- header : & str ) -> String
306- {
300+ fn suggestion_snippet_for_continue_inside_else < ' a > ( ctx : & EarlyContext , data : & ' a LintData , header : & str ) -> String {
307301 let cond_code = snippet ( ctx, data. if_cond . span , ".." ) ;
308- let mut if_code = format ! ( "if {} {{\n " , cond_code) ;
302+ let mut if_code = format ! ( "if {} {{\n " , cond_code) ;
309303
310304 // Region B
311305 let block_code = & snippet ( ctx, data. if_block . span , ".." ) . into_owned ( ) ;
@@ -318,13 +312,12 @@ fn suggestion_snippet_for_continue_inside_else<'a>(ctx: &EarlyContext,
318312 // These is the code in the loop block that follows the if/else construction
319313 // we are complaining about. We want to pull all of this code into the
320314 // `then` block of the `if` statement.
321- let to_annex = data. block_stmts [ data. stmt_idx +1 ..]
322- . iter ( )
323- . map ( |stmt| {
324- original_sp ( stmt. span , DUMMY_SP )
325- } )
326- . map ( |span| snippet_block ( ctx, span, ".." ) . into_owned ( ) )
327- . collect :: < Vec < _ > > ( ) . join ( "\n " ) ;
315+ let to_annex = data. block_stmts [ data. stmt_idx + 1 ..]
316+ . iter ( )
317+ . map ( |stmt| original_sp ( stmt. span , DUMMY_SP ) )
318+ . map ( |span| snippet_block ( ctx, span, ".." ) . into_owned ( ) )
319+ . collect :: < Vec < _ > > ( )
320+ . join ( "\n " ) ;
328321
329322 let mut ret = String :: from ( header) ;
330323
@@ -336,24 +329,22 @@ fn suggestion_snippet_for_continue_inside_else<'a>(ctx: &EarlyContext,
336329}
337330
338331fn check_and_warn < ' a > ( ctx : & EarlyContext , expr : & ' a ast:: Expr ) {
339- with_loop_block ( expr, |loop_block| {
340- for ( i, stmt) in loop_block. stmts . iter ( ) . enumerate ( ) {
341- with_if_expr ( stmt, |if_expr, cond, then_block, else_expr| {
342- let data = & LintData {
343- stmt_idx : i,
344- if_expr : if_expr,
345- if_cond : cond,
346- if_block : then_block,
347- else_expr : else_expr,
348- block_stmts : & loop_block. stmts ,
349- } ;
350- if needless_continue_in_else ( else_expr) {
351- emit_warning ( ctx, data, DROP_ELSE_BLOCK_AND_MERGE_MSG , LintType :: ContinueInsideElseBlock ) ;
352- } else if is_first_block_stmt_continue ( then_block) {
353- emit_warning ( ctx, data, DROP_ELSE_BLOCK_MSG , LintType :: ContinueInsideThenBlock ) ;
354- }
355- } ) ;
356- }
332+ with_loop_block ( expr, |loop_block| for ( i, stmt) in loop_block. stmts . iter ( ) . enumerate ( ) {
333+ with_if_expr ( stmt, |if_expr, cond, then_block, else_expr| {
334+ let data = & LintData {
335+ stmt_idx : i,
336+ if_expr : if_expr,
337+ if_cond : cond,
338+ if_block : then_block,
339+ else_expr : else_expr,
340+ block_stmts : & loop_block. stmts ,
341+ } ;
342+ if needless_continue_in_else ( else_expr) {
343+ emit_warning ( ctx, data, DROP_ELSE_BLOCK_AND_MERGE_MSG , LintType :: ContinueInsideElseBlock ) ;
344+ } else if is_first_block_stmt_continue ( then_block) {
345+ emit_warning ( ctx, data, DROP_ELSE_BLOCK_MSG , LintType :: ContinueInsideThenBlock ) ;
346+ }
347+ } ) ;
357348 } ) ;
358349}
359350
@@ -378,7 +369,7 @@ fn check_and_warn<'a>(ctx: &EarlyContext, expr: &'a ast::Expr) {
378369/// an empty string will be returned in that case.
379370pub fn erode_from_back ( s : & str ) -> String {
380371 let mut ret = String :: from ( s) ;
381- while ret. pop ( ) . map_or ( false , |c| c != '}' ) { }
372+ while ret. pop ( ) . map_or ( false , |c| c != '}' ) { }
382373 while let Some ( c) = ret. pop ( ) {
383374 if !c. is_whitespace ( ) {
384375 ret. push ( c) ;
@@ -409,10 +400,10 @@ pub fn erode_from_back(s: &str) -> String {
409400///
410401pub fn erode_from_front ( s : & str ) -> String {
411402 s. chars ( )
412- . skip_while ( |c| c. is_whitespace ( ) )
413- . skip_while ( |c| * c == '{' )
414- . skip_while ( |c| * c == '\n' )
415- . collect :: < String > ( )
403+ . skip_while ( |c| c. is_whitespace ( ) )
404+ . skip_while ( |c| * c == '{' )
405+ . skip_while ( |c| * c == '\n' )
406+ . collect :: < String > ( )
416407}
417408
418409/// If `s` contains the code for a block, delimited by braces, this function
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