Add some parsing test

src/main.v

@@ -18,11 +18,17 @@ fn main() {
 		eprintln(fp.usage())
 		exit(1)
 	}
+	mut deps := []DependencyGraph{}
 	for folder in folders {
 		println('Processing ${folder} ...')
 		dep := process_folder(folder, a_string) or {
 			eprintln(err)
 			continue
 		}
+		deps << dep
+	}
+	output_d2(deps) or {
+		eprintln(err)
+		exit(1)
 	}
 }

src/output_d2.v

@@ -0,0 +1,5 @@
+module main
+
+fn output_d2(deps []DependencyGraph) ![]string {
+	return []string{}
+}

src/process_file.v

@@ -14,9 +14,12 @@ fn process_file(file string, language string) !DependencyGraph {
 	if !os.is_file(file) {
 		return error("not a file ${file}")
 	}
-	dep := DependencyGraph{
+	mut dep := DependencyGraph{
 		language: language,
 		file_path: file,
 	}
+	if is_haskell_file(file) {
+		process_file_haskell(mut dep)!
+	}
 	return dep
 }

src/process_file_haskell.v

@@ -0,0 +1,26 @@
+module main
+
+import os
+import regex
+
+fn is_haskell_file(file string) bool {
+	return file.ends_with('.hs')
+}
+
+fn process_file_haskell(mut dep &DependencyGraph) ! {
+	mut name := dep.file_path.split(os.path_separator)
+	if 'src' in name {
+		name.drop(name.index('src'))
+	}
+	if 'app' in name {
+		name.drop(name.index('app'))
+	}
+	dep.name << name.join('.')
+	query := r'^import (qualified)? ([\w.]+)'
+	mut re := regex.regex_opt(query)!
+	lines := os.read_file(dep.file_path)!
+	for imports in re.find_all_str(lines) {
+		dep_tmp := re.get_group_by_id(imports, 2)
+		dep.dependencies << dep_tmp
+	}
+}