visitor: Handle specified line ranges in visit_stmt

This commit adds a very rough implementation of handling the specified
line ranges in `config.file_lines_map` for statements. It reformats a
statement if its span is fully contained in the set of lines specified
for the file.

The implementation here is intended as a proof of concept, and
demonstration that the machinery added in the preceding commits is
functional. A final implementation would likely hook in via the
`Rewrite` trait.

Refs #434

Author: kamalmarhubi

src/visitor.rs

@@ -16,7 +16,7 @@ use strings::string_buffer::StringBuffer;
 
 use Indent;
 use utils;
-use codemap::SpanUtils;
+use codemap::{LineRangeUtils, SpanUtils};
 use config::Config;
 use rewrite::{Rewrite, RewriteContext};
 use comment::rewrite_comment;
@@ -47,6 +47,11 @@ impl<'a> FmtVisitor<'a> {
                self.codemap.lookup_char_pos(stmt.span.lo),
                self.codemap.lookup_char_pos(stmt.span.hi));
 
+        // FIXME(#434): Move this check to somewhere more central, eg Rewrite.
+        if !self.config.file_lines.contains(&self.codemap.lookup_line_range(stmt.span)) {
+            return;
+        }
+
         match stmt.node {
             ast::StmtKind::Decl(ref decl, _) => {
                 if let ast::DeclKind::Item(ref item) = decl.node {

tests/source/file-lines-1.rs

@@ -0,0 +1,29 @@
+// rustfmt-file_lines: [{"file":"tests/source/file-lines-1.rs","range":[4,8]}]
+
+fn floaters() {
+    let x = Foo {
+                field1: val1,
+                field2: val2,
+            }
+            .method_call().method_call();
+
+    let y = if cond {
+                val1
+            } else {
+                val2
+            }
+                .method_call();
+
+    {
+        match x {
+            PushParam => {
+                // params are 1-indexed
+                stack.push(mparams[match cur.to_digit(10) {
+                                            Some(d) => d as usize - 1,
+                                            None => return Err("bad param number".to_owned()),
+                                        }]
+                               .clone());
+            }
+        }
+    }
+}

tests/source/file-lines-2.rs

@@ -0,0 +1,29 @@
+// rustfmt-file_lines: [{"file":"tests/source/file-lines-2.rs","range":[10,15]}]
+
+fn floaters() {
+    let x = Foo {
+                field1: val1,
+                field2: val2,
+            }
+            .method_call().method_call();
+
+    let y = if cond {
+                val1
+            } else {
+                val2
+            }
+            .method_call();
+
+    {
+        match x {
+            PushParam => {
+                // params are 1-indexed
+                stack.push(mparams[match cur.to_digit(10) {
+                                            Some(d) => d as usize - 1,
+                                            None => return Err("bad param number".to_owned()),
+                                        }]
+                               .clone());
+            }
+        }
+    }
+}

tests/source/file-lines-3.rs

@@ -0,0 +1,29 @@
+// rustfmt-file_lines: [{"file":"tests/source/file-lines-3.rs","range":[4,8]},{"file":"tests/source/file-lines-3.rs","range":[10,15]}]
+
+fn floaters() {
+    let x = Foo {
+                field1: val1,
+                field2: val2,
+            }
+            .method_call().method_call();
+
+    let y = if cond {
+                val1
+            } else {
+                val2
+            }
+                .method_call();
+
+    {
+        match x {
+            PushParam => {
+                // params are 1-indexed
+                stack.push(mparams[match cur.to_digit(10) {
+                                            Some(d) => d as usize - 1,
+                                            None => return Err("bad param number".to_owned()),
+                                        }]
+                               .clone());
+            }
+        }
+    }
+}

tests/source/file-lines-4.rs

@@ -0,0 +1,30 @@
+// rustfmt-file_lines: []
+// (Test that nothing is formatted if an empty array is specified.)
+
+fn floaters() {
+    let x = Foo {
+                field1: val1,
+                field2: val2,
+            }
+            .method_call().method_call();
+
+    let y = if cond {
+                val1
+            } else {
+                val2
+            }
+                .method_call();
+
+    {
+        match x {
+            PushParam => {
+                // params are 1-indexed
+                stack.push(mparams[match cur.to_digit(10) {
+                                            Some(d) => d as usize - 1,
+                                            None => return Err("bad param number".to_owned()),
+                                        }]
+                               .clone());
+            }
+        }
+    }
+}

tests/target/file-lines-1.rs

@@ -0,0 +1,30 @@
+// rustfmt-file_lines: [{"file":"tests/source/file-lines-1.rs","range":[4,8]}]
+
+fn floaters() {
+    let x = Foo {
+            field1: val1,
+            field2: val2,
+        }
+        .method_call()
+        .method_call();
+
+    let y = if cond {
+                val1
+            } else {
+                val2
+            }
+                .method_call();
+
+    {
+        match x {
+            PushParam => {
+                // params are 1-indexed
+                stack.push(mparams[match cur.to_digit(10) {
+                                            Some(d) => d as usize - 1,
+                                            None => return Err("bad param number".to_owned()),
+                                        }]
+                               .clone());
+            }
+        }
+    }
+}

tests/target/file-lines-2.rs

@@ -0,0 +1,29 @@
+// rustfmt-file_lines: [{"file":"tests/source/file-lines-2.rs","range":[10,15]}]
+
+fn floaters() {
+    let x = Foo {
+                field1: val1,
+                field2: val2,
+            }
+            .method_call().method_call();
+
+    let y = if cond {
+            val1
+        } else {
+            val2
+        }
+        .method_call();
+
+    {
+        match x {
+            PushParam => {
+                // params are 1-indexed
+                stack.push(mparams[match cur.to_digit(10) {
+                                            Some(d) => d as usize - 1,
+                                            None => return Err("bad param number".to_owned()),
+                                        }]
+                               .clone());
+            }
+        }
+    }
+}

tests/target/file-lines-3.rs

@@ -0,0 +1,30 @@
+// rustfmt-file_lines: [{"file":"tests/source/file-lines-3.rs","range":[4,8]},{"file":"tests/source/file-lines-3.rs","range":[10,15]}]
+
+fn floaters() {
+    let x = Foo {
+            field1: val1,
+            field2: val2,
+        }
+        .method_call()
+        .method_call();
+
+    let y = if cond {
+            val1
+        } else {
+            val2
+        }
+        .method_call();
+
+    {
+        match x {
+            PushParam => {
+                // params are 1-indexed
+                stack.push(mparams[match cur.to_digit(10) {
+                                            Some(d) => d as usize - 1,
+                                            None => return Err("bad param number".to_owned()),
+                                        }]
+                               .clone());
+            }
+        }
+    }
+}

tests/target/file-lines-4.rs

@@ -0,0 +1,30 @@
+// rustfmt-file_lines: []
+// (Test that nothing is formatted if an empty array is specified.)
+
+fn floaters() {
+    let x = Foo {
+                field1: val1,
+                field2: val2,
+            }
+            .method_call().method_call();
+
+    let y = if cond {
+                val1
+            } else {
+                val2
+            }
+                .method_call();
+
+    {
+        match x {
+            PushParam => {
+                // params are 1-indexed
+                stack.push(mparams[match cur.to_digit(10) {
+                                            Some(d) => d as usize - 1,
+                                            None => return Err("bad param number".to_owned()),
+                                        }]
+                               .clone());
+            }
+        }
+    }
+}