Create info module with business logic routines

Currently these routines number two: file type checking based on a file's name, and source file checking, also based on the file's name.

1 files changed, 42 insertions, 0 deletions

diff --git a/src/info/sources.rs b/src/info/sources.rs
new file mode 100644
index 0000000..e4b5e0c
--- /dev/null
+++ b/src/info/sources.rs
@@ -0,0 +1,42 @@
+use std::path::PathBuf;
+
+use fs::File;
+
+
+impl<'_> File<'_> {
+
+    /// For this file, return a vector of alternate file paths that, if any of
+    /// them exist, mean that *this* file should be coloured as “compiled”.
+    ///
+    /// The point of this is to highlight compiled files such as `foo.o` when
+    /// their source file `foo.c` exists in the same directory. It's too
+    /// dangerous to highlight *all* compiled, so the paths in this vector
+    /// are checked for existence first: for example, `foo.js` is perfectly
+    /// valid without `foo.coffee`.
+    pub fn get_source_files(&self) -> Vec<PathBuf> {
+        if let Some(ref ext) = self.ext {
+            match &ext[..] {
+                "class" => vec![self.path.with_extension("java")],  // Java
+                "css"   => vec![self.path.with_extension("sass"),   self.path.with_extension("less")],  // SASS, Less
+                "elc"   => vec![self.path.with_extension("el")],    // Emacs Lisp
+                "hi"    => vec![self.path.with_extension("hs")],    // Haskell
+                "js"    => vec![self.path.with_extension("coffee"), self.path.with_extension("ts")],  // CoffeeScript, TypeScript
+                "o"     => vec![self.path.with_extension("c"),      self.path.with_extension("cpp")], // C, C++
+                "pyc"   => vec![self.path.with_extension("py")],    // Python
+
+                "aux" => vec![self.path.with_extension("tex")],  // TeX: auxiliary file
+                "bbl" => vec![self.path.with_extension("tex")],  // BibTeX bibliography file
+                "blg" => vec![self.path.with_extension("tex")],  // BibTeX log file
+                "lof" => vec![self.path.with_extension("tex")],  // TeX list of figures
+                "log" => vec![self.path.with_extension("tex")],  // TeX log file
+                "lot" => vec![self.path.with_extension("tex")],  // TeX list of tables
+                "toc" => vec![self.path.with_extension("tex")],  // TeX table of contents
+
+                _ => vec![],  // No source files if none of the above
+            }
+        }
+        else {
+            vec![]  // No source files if there's no extension, either!
+        }
+    }
+}