1 files changed, 95 insertions, 0 deletions
diff --git a/libbuild2/script/lexer.hxx b/libbuild2/script/lexer.hxx
new file mode 100644
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+++ b/libbuild2/script/lexer.hxx
@@ -0,0 +1,95 @@
+// file      : libbuild2/script/lexer.hxx -*- C++ -*-
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef LIBBUILD2_SCRIPT_LEXER_HXX
+#define LIBBUILD2_SCRIPT_LEXER_HXX
+
+#include <libbuild2/types.hxx>
+#include <libbuild2/utility.hxx>
+
+#include <libbuild2/lexer.hxx>
+
+#include <libbuild2/script/token.hxx>
+
+namespace build2
+{
+  namespace script
+  {
+    struct lexer_mode: build2::lexer_mode
+    {
+      using base_type = build2::lexer_mode;
+
+      enum
+      {
+        command_expansion = base_type::value_next,
+        here_line_single,
+        here_line_double,
+
+        value_next
+      };
+
+      lexer_mode () = default;
+      lexer_mode (value_type v): base_type (v) {}
+      lexer_mode (base_type v): base_type (v) {}
+    };
+
+    class lexer: public build2::lexer
+    {
+    public:
+      using base_lexer = build2::lexer;
+      using base_mode = build2::lexer_mode;
+
+      // Note that neither the name nor escape arguments are copied.
+      //
+      lexer (istream& is,
+             const path_name& name,
+             lexer_mode m,
+             const char* escapes = nullptr)
+          : base_lexer (is, name, 1 /* line */,
+                        nullptr     /* escapes */,
+                        false       /* set_mode */)
+      {
+        mode (m, '\0', escapes);
+      }
+
+      virtual void
+      mode (base_mode,
+            char = '\0',
+            optional<const char*> = nullopt) override;
+
+      // Number of quoted (double or single) tokens since last reset.
+      //
+      size_t
+      quoted () const {return quoted_;}
+
+      void
+      reset_quoted (size_t q) {quoted_ = q;}
+
+      virtual token
+      next () override;
+
+    protected:
+      lexer (istream& is, const path_name& name, uint64_t line,
+             const char* escapes,
+             bool set_mode)
+          : base_lexer (is, name, line, escapes, set_mode) {}
+
+      // Return the next token if it is a command operator (|, ||, &&,
+      // redirect, or cleanup) and nullopt otherwise.
+      //
+      optional<token>
+      next_cmd_op (const xchar&, // The token first character (last got char).
+                   bool sep,     // The token is separated.
+                   lexer_mode);  // The current (potentially "expired") mode.
+
+    private:
+      token
+      next_line ();
+
+    protected:
+      size_t quoted_;
+    };
+  }
+}
+
+#endif // LIBBUILD2_SCRIPT_LEXER_HXX