1 files changed, 18 insertions, 0 deletions
diff --git a/src/include/token.H b/src/include/token.H
index 71d6cb10..b57b69d6 100644
--- a/src/include/token.H
+++ b/src/include/token.H
@@ -79,6 +79,19 @@ namespace OpenAxiom {
    using LineNumber = std::size_t;
    using ColumnIndex = std::size_t;
 
+   struct Locus {
+      LineNumber line;
+      ColumnIndex column;
+   };
+
+   std::ostream& operator<<(std::ostream&, const Locus&);
+
+   // Program text region
+   struct Region {
+      Locus start;
+      Locus end;
+   };
+
    // Given a symbolic or alphabetic token, retrieve its category
    // and associated abstract value.
    struct TokenClassification {
@@ -92,6 +105,11 @@ namespace OpenAxiom {
 
    TokenClassification classify(const std::string&);
 
+   // Token data structure: a region of text with a classification.
+   struct Token : TokenClassification, Region {
+      using Location = Locus;
+   };
+
    // Cursor into a fragment.
    struct FragmentCursor {
       std::size_t line;         // index of a line in a fragment