Make a New Rustacean-inspired refactor.

In the process of writing New Rustacean [e020], I realized that
the structure I was building wasn't quite right: it was treating
`Metadata` as fundamental to the `item` module, and `item`
as a child of the `builder` element, when in fact `item`s are
their own distinct concepts, and `Metadata` deserved to have
its own module. So here we are! It was also a good opportunity
to move `parse_metadata` to `Metadata::parse`, which is a far
more Rustic way of structuring this.

[e020]: http://newrustacean.com/show_notes/e020/

P.S. If this commit message seems a bit more articulate, you
can thank [The Bike Shed 105] for reminding me that this kind
of context can be incredibly helpful. Probably not so much in
*this* specific commit, but generally speaking.

[The Bike Shed 105]: http://bikeshed.fm/105

src/builder/mod.rs

@@ -1,7 +1,5 @@
 //! Generate the site content.
 
-mod item;
-
 // Standard library
 use std::fs::File;
 use std::io::prelude::*;
@@ -15,7 +13,7 @@ use syntect::highlighting::ThemeSet;
 // First party
 use config::Config;
 use syntax_highlighting::syntax_highlight;
-
+use item;
 
 /// Load the `Paths` for all markdown files in the specified content directory.
 fn glob_md_paths(site_directory: &PathBuf, config: &Config) -> Result<Paths, String> {
@@ -58,7 +56,7 @@ pub fn build(site_directory: PathBuf) -> Result<(), String> {
     for path_result in markdown_paths {
         let path = path_result.map_err(|e| format!("{:?}", e))?;
         let contents = load_file(&path)?;
-        let metadata = item::parse_metadata(&contents, &path)?;
+        let metadata = item::Metadata::parse(&contents, &path)?;
 
         let mut pandoc = pandoc.clone();
         pandoc.set_input(InputKind::Pipe(contents));
@@ -95,10 +93,11 @@ fn write_file(output_dir: &Path, slug: &str, contents: &str) -> Result<(), Strin
     let path = output_dir.join(slug).with_extension("html");
 
     let mut fd = File::create(&path).map_err(|err| {
-            format!("Could not open {} for write: {}",
-                    path.to_string_lossy(),
-                    err)
-        })?;
+                     format!("Could not open {} for write: {}",
+                             path.to_string_lossy(),
+                             err)
+                 })?;
 
     write!(fd, "{}", contents).map_err(|err| format!("{:?}", err.kind()))
 }
+

src/builder/item.rs → src/item/metadata.rs

@@ -5,7 +5,6 @@
 use std::collections::HashMap;
 use std::error::Error;
 use std::path::Path;
-use std::str::FromStr;
 
 // Third-party
 use yaml_rust::{yaml, Yaml, YamlLoader};
@@ -20,6 +19,46 @@ pub struct Metadata {
     pub extra: Option<HashMap<String, ExtraMetadata>>,
 }
 
+impl Metadata {
+    pub fn parse(content: &str, file_name: &Path) -> Result<Metadata, String> {
+        let metadata = extract_metadata(&content)
+        .ok_or(format!("file `{}` passed to `Metadata::parse` has no metadata",
+                       file_name.to_string_lossy()))?;
+
+        let bad_yaml_message = |reason: &str| {
+            format!("file `{}` passed to `Metadata::parse` had invalid metadata: {}\n{}",
+                    file_name.to_string_lossy(),
+                    metadata,
+                    reason)
+        };
+
+        let yaml = YamlLoader::load_from_str(&metadata)
+                          .map_err(|reason| bad_yaml_message(&reason.description()))?;
+
+        let yaml = yaml.into_iter()
+            .next()
+            .ok_or(bad_yaml_message("empty metadata block"))?;
+        let yaml = yaml.as_hash().ok_or(bad_yaml_message("could not parse as hash"))?;
+
+        // TODO: Parse from YAML
+        let slug = file_name.file_stem()
+            .ok_or(format!("file name `{}` passed to `Metadata::parse` has no stem",
+                           file_name.to_string_lossy()))?
+            .to_str()
+            .ok_or(format!("file name `{}` passed to `Metadata::parse` has invalid UTF-8",
+                           file_name.to_string_lossy()))?;
+
+        let title = case_insensitive_string("title", "Title", yaml, Required::No)
+            .unwrap_or("".into());
+
+        Ok(Metadata {
+               title: title,
+               slug: slug.to_string(),
+               extra: None,
+           })
+    }
+}
+
 pub enum ExtraMetadata {
     SingleLineString(String),
     MultiLineString(String),
@@ -61,41 +100,6 @@ fn extract_metadata<'c>(content: &'c str) -> Option<String> {
 }
 
 
-pub fn parse_metadata(content: &str, file_name: &Path) -> Result<Metadata, String> {
-    let metadata = extract_metadata(&content)
-        .ok_or(format!("file `{}` passed to `parse_metadata` has no metadata",
-                       file_name.to_string_lossy()))?;
-
-    let bad_yaml_message = |reason: &str| {
-        format!("file `{}` passed to `parse_metadata` had invalid metadata: {}\n{}",
-                file_name.to_string_lossy(), metadata, reason)
-    };
-
-    let yaml = YamlLoader::load_from_str(&metadata)
-                          .map_err(|reason| bad_yaml_message(&reason.description()))?;
-
-    let yaml = yaml.into_iter().next().ok_or(bad_yaml_message("empty metadata block"))?;
-    let yaml = yaml.as_hash().ok_or(bad_yaml_message("could not parse as hash"))?;
-
-    // TODO: Parse from YAML
-    let slug = file_name.file_stem()
-                        .ok_or(
-                            format!("file name `{}` passed to `parse_metadata` has no stem",
-                                    file_name.to_string_lossy()))?
-                        .to_str()
-                        .ok_or(
-                            format!("file name `{}` passed to `parse_metadata` has invalid UTF-8",
-                                    file_name.to_string_lossy()))?;
-
-    let title = case_insensitive_string("title", "Title", yaml, Required::No).unwrap_or("".into());
-
-    Ok(Metadata {
-        title: title,
-        slug: slug.to_string(),
-        extra: None,
-    })
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -109,9 +113,8 @@ Title: With Terminal Dashes
 Some other text!e
         ";
 
-        assert_eq!(
-            extract_metadata(&has_metadata),
-            Some("Title: With Terminal Dashes".into()));
+        assert_eq!(extract_metadata(&has_metadata),
+                   Some("Title: With Terminal Dashes".into()));
 
         let has_metadata_terminal_dots = "---
 Title: With Terminal Dots
@@ -120,9 +123,8 @@ Title: With Terminal Dots
 Some other text!
         ";
 
-        assert_eq!(
-            extract_metadata(&has_metadata_terminal_dots),
-            Some("Title: With Terminal Dots".into()));
+        assert_eq!(extract_metadata(&has_metadata_terminal_dots),
+                   Some("Title: With Terminal Dots".into()));
 
         let no_metadata = "
 Some text, no metadata though.
@@ -150,9 +152,8 @@ Title: Who cares how many *initial* empty lines there are?
 ---
         ";
 
-        assert_eq!(
-            extract_metadata(&has_space_before_opening),
-            Some("Title: Who cares how many *initial* empty lines there are?".into()));
+        assert_eq!(extract_metadata(&has_space_before_opening),
+                   Some("Title: Who cares how many *initial* empty lines there are?".into()));
 
         let multiline_metadata = "---
 Jedi: Luke Skywalker
@@ -163,9 +164,8 @@ Badass: Princess Leia
 Whatever other content...
         ";
 
-        assert_eq!(
-            extract_metadata(&multiline_metadata),
-            Some("Jedi: Luke Skywalker\nRogue: Han Solo\nBadass: Princess Leia".into()));
+        assert_eq!(extract_metadata(&multiline_metadata),
+                   Some("Jedi: Luke Skywalker\nRogue: Han Solo\nBadass: Princess Leia".into()));
 
         let whole_lines_only_please = "---This: Is Not Valid
 Even: Thought it *almost* looks valid.
@@ -175,3 +175,4 @@ Even: Thought it *almost* looks valid.
         assert_eq!(extract_metadata(&whole_lines_only_please), None);
     }
 }
+

src/item/mod.rs

@@ -0,0 +1,3 @@
+pub mod metadata;
+
+pub use self::metadata::{Metadata,ExtraMetadata};

src/lib.rs

@@ -10,12 +10,13 @@ mod builder;
 mod config;
 mod creator;
 mod initializer;
+mod item;
 mod server;
 mod syntax_highlighting;
 mod validated_types;
 mod yaml_util;
 
-pub use initializer::init;
 pub use builder::build;
 pub use creator::create;
+pub use initializer::init;
 pub use server::serve;