Simplified file structure

src/token/List.go

@@ -0,0 +1,78 @@
+package token
+
+import (
+	"strings"
+)
+
+// List is a slice of tokens.
+type List []Token
+
+// IndexKind returns the position of a token kind within a token list.
+func (list List) IndexKind(kind Kind) int {
+	for i, token := range list {
+		if token.Kind == kind {
+			return i
+		}
+	}
+
+	return -1
+}
+
+// LastIndexKind returns the position of the last token kind within a token list.
+func (list List) LastIndexKind(kind Kind) int {
+	for i := len(list) - 1; i >= 0; i-- {
+		if list[i].Kind == kind {
+			return i
+		}
+	}
+
+	return -1
+}
+
+// Split calls the callback function on each set of tokens in a comma separated list.
+func (list List) Split(call func(List) error) error {
+	start := 0
+	groupLevel := 0
+
+	for i, t := range list {
+		switch t.Kind {
+		case GroupStart, ArrayStart, BlockStart:
+			groupLevel++
+
+		case GroupEnd, ArrayEnd, BlockEnd:
+			groupLevel--
+
+		case Separator:
+			if groupLevel > 0 {
+				continue
+			}
+
+			parameter := list[start:i]
+			err := call(parameter)
+
+			if err != nil {
+				return err
+			}
+
+			start = i + 1
+		}
+	}
+
+	if start != len(list) {
+		parameter := list[start:]
+		return call(parameter)
+	}
+
+	return nil
+}
+
+// Text returns the concatenated token text.
+func (list List) Text(source []byte) string {
+	tmp := strings.Builder{}
+
+	for _, t := range list {
+		tmp.WriteString(t.Text(source))
+	}
+
+	return tmp.String()
+}