restructure parsing and typing modules

* parsing backend submodules
* move typing to its own module

src/ast/module.rs

@@ -0,0 +1,66 @@
+use std::path::Path;
+use super::Definition;
+
+#[derive(Debug, PartialEq, Clone)]
+pub struct ModulePath {
+    components: Vec<String>,
+}
+
+impl std::fmt::Display for ModulePath {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_fmt(format_args!("{}", self.components.join("::")))
+    }
+}
+
+impl From<&Path> for ModulePath {
+    fn from(path: &Path) -> Self {
+        let meta = std::fs::metadata(path).unwrap();
+        ModulePath {
+            components: path
+                .components()
+                .map(|component| match component {
+                    std::path::Component::Normal(n) => {
+                        if meta.is_file() {
+                            n.to_str().unwrap().split(".").nth(0).unwrap().to_string()
+                        } else if meta.is_dir() {
+                            n.to_str().unwrap().to_string()
+                        } else {
+                            // XXX: symlinks?
+                            unreachable!()
+                        }
+                    }
+                    _ => unreachable!(),
+                })
+                .collect(),
+        }
+    }
+}
+
+impl From<&str> for ModulePath {
+    fn from(string: &str) -> Self {
+        ModulePath {
+            components: string.split("::").map(|c| c.to_string()).collect(),
+        }
+    }
+}
+
+type ImportPath = ModulePath;
+
+#[derive(Debug, PartialEq)]
+pub struct Module {
+    pub file: Option<std::path::PathBuf>,
+    pub path: ModulePath,
+    pub definitions: Vec<Definition>,
+    pub imports: Vec<ImportPath>,
+}
+
+impl Module {
+    pub fn new(path: ModulePath) -> Self {
+        Module {
+            path,
+            file: None,
+            definitions: vec![],
+            imports: vec![],
+        }
+    }
+}