Implemented a basic scanner

src/scanner/scanner.go

@@ -0,0 +1,147 @@
+package scanner
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+
+	"git.urbach.dev/cli/q/src/build"
+	"git.urbach.dev/cli/q/src/fs"
+)
+
+// scanner is used to scan files before the actual compilation step.
+type scanner struct {
+	files  chan *fs.File
+	errors chan error
+	build  *build.Build
+	queued sync.Map
+	group  sync.WaitGroup
+}
+
+// queue scans the list of files.
+func (s *scanner) queue(files ...string) {
+	for _, file := range files {
+		stat, err := os.Stat(file)
+
+		if err != nil {
+			s.errors <- err
+			return
+		}
+
+		if stat.IsDir() {
+			s.queueDirectory(file, "main")
+		} else {
+			s.queueFile(file, "main")
+		}
+	}
+}
+
+// queueDirectory queues an entire directory to be scanned.
+func (s *scanner) queueDirectory(directory string, pkg string) {
+	_, loaded := s.queued.LoadOrStore(directory, nil)
+
+	if loaded {
+		return
+	}
+
+	err := fs.Walk(directory, func(name string) {
+		if !strings.HasSuffix(name, ".q") {
+			return
+		}
+
+		tmp := name[:len(name)-2]
+
+		for {
+			underscore := strings.LastIndexByte(tmp, '_')
+
+			if underscore == -1 {
+				break
+			}
+
+			condition := tmp[underscore+1:]
+
+			switch condition {
+			case "linux":
+				if s.build.OS != build.Linux {
+					return
+				}
+
+			case "mac":
+				if s.build.OS != build.Mac {
+					return
+				}
+
+			case "unix":
+				if s.build.OS != build.Linux && s.build.OS != build.Mac {
+					return
+				}
+
+			case "windows":
+				if s.build.OS != build.Windows {
+					return
+				}
+
+			case "x86":
+				if s.build.Arch != build.X86 {
+					return
+				}
+
+			case "arm":
+				if s.build.Arch != build.ARM {
+					return
+				}
+
+			default:
+				return
+			}
+
+			tmp = tmp[:underscore]
+		}
+
+		fullPath := filepath.Join(directory, name)
+		s.queueFile(fullPath, pkg)
+	})
+
+	if err != nil {
+		s.errors <- err
+	}
+}
+
+// queueFile queues a single file to be scanned.
+func (s *scanner) queueFile(file string, pkg string) {
+	_, loaded := s.queued.LoadOrStore(file, nil)
+
+	if loaded {
+		return
+	}
+
+	s.group.Add(1)
+
+	go func() {
+		defer s.group.Done()
+		err := s.scanFile(file, pkg)
+
+		if err != nil {
+			s.errors <- err
+		}
+	}()
+}
+
+// scanFile scans a single file.
+func (s *scanner) scanFile(path string, pkg string) error {
+	contents, err := os.ReadFile(path)
+
+	if err != nil {
+		return err
+	}
+
+	file := &fs.File{
+		Path:    path,
+		Package: pkg,
+		Bytes:   contents,
+	}
+
+	s.files <- file
+	return nil
+}