From 75cda24e0eb81f48649ad97283b657324082dd3b Mon Sep 17 00:00:00 2001
From: strange <kawk256@gmail.com>
Date: Tue, 1 Dec 2009 15:53:38 -0700
Subject: [PATCH] Added GDB::StringFollower.

StringFollower basically will replace all of the ugly-looking dynamic_cast<>s
that are required to get data out of a String instance.
---
 src/interface/gdb/BreakpointObserver.cpp |  2 ++
 src/interface/gdb/StringFollower.cpp     | 53 ++++++++++++++++++++++++++++++++
 src/interface/gdb/StringFollower.h       | 47 ++++++++++++++++++++++++++++
 3 files changed, 102 insertions(+)
 create mode 100644 src/interface/gdb/StringFollower.cpp
 create mode 100644 src/interface/gdb/StringFollower.h

diff --git a/src/interface/gdb/BreakpointObserver.cpp b/src/interface/gdb/BreakpointObserver.cpp
index 0fd3241..e0aafd9 100644
--- a/src/interface/gdb/BreakpointObserver.cpp
+++ b/src/interface/gdb/BreakpointObserver.cpp
@@ -1,3 +1,5 @@
+#include <iostream>
+
 #include "BreakpointObserver.h"
 
 namespace Aesalon {
diff --git a/src/interface/gdb/StringFollower.cpp b/src/interface/gdb/StringFollower.cpp
new file mode 100644
index 0000000..fda3703
--- /dev/null
+++ b/src/interface/gdb/StringFollower.cpp
@@ -0,0 +1,53 @@
+#include <sstream>
+
+#include "StringFollower.h"
+
+namespace Aesalon {
+namespace Interface {
+namespace GDB {
+
+std::string StringFollower::follow(std::string path) {
+    std::stringstream stream;
+    stream << path;
+    
+    std::string token;
+    
+    while(stream >> token) {
+        if(token[0] == '[') { /* list element */
+            if(token[token.length()-1] != ']') {
+                throw StringFollowerInvalidPathException("Expected terminating ']' at end of token.");
+            }
+            std::istringstream number_stream(token.substr(1, token.length()-2));
+            int number;
+            number_stream >> number;
+            
+            data = data.to<ParseList>()->get_element(number);
+        }
+        else if(token[0] == '\'') { /* tuple element */
+            if(token[token.length()-1] != '\'') {
+                throw StringFollowerInvalidPathException("Expected terminating \' at end of token.");
+            }
+            std::string key = token.substr(1, token.length()-2);
+            data = data.to<ParseTuple>()->get_element(key);
+        }
+        else if(token[0] == '\"') { /* tuple element */
+            if(token[token.length()-1] != '\"') {
+                throw StringFollowerInvalidPathException("Expected terminating \" at end of token.");
+            }
+            std::string key = token.substr(1, token.length()-2);
+            data = data.to<ParseTuple>()->get_element(key);
+        }
+        else if(token == "lhs") { /* left side of a result */
+            data = new ParseString(data.to<ParseResult>()->get_name());
+        }
+        else if(token == "rhs") { /* right side of a result */
+            data = data.to<ParseResult>()->get_value();
+        }
+    }
+    
+    return data.to<ParseString>()->get_data();
+}
+
+} // namespace GDB
+} // namespace Interface
+} // namespace Aesalon
diff --git a/src/interface/gdb/StringFollower.h b/src/interface/gdb/StringFollower.h
new file mode 100644
index 0000000..a9f3889
--- /dev/null
+++ b/src/interface/gdb/StringFollower.h
@@ -0,0 +1,47 @@
+#ifndef AESALON_INTERFACE_GDB_STRING_FOLLOWER_H
+#define AESALON_INTERFACE_GDB_STRING_FOLLOWER_H
+
+#include <string>
+
+#include "misc/Exception.h"
+#include "String.h"
+
+namespace Aesalon {
+namespace Interface {
+namespace GDB {
+
+class StringFollowerException : public Misc::Exception {
+public:
+    StringFollowerException(std::string message) : Misc::Exception(message) {}
+    virtual ~StringFollowerException() {}
+};
+
+class StringFollowerInvalidPathException : public StringFollowerException {
+public:
+    StringFollowerInvalidPathException(std::string message) : StringFollowerException(message) {}
+    virtual ~StringFollowerInvalidPathException() {}
+};
+
+/** Class to find an element within a String. */
+class StringFollower {
+private:
+    Misc::SmartPointer<ParseData> data;
+public:
+    StringFollower(Misc::SmartPointer<String> string) : data(string->get_data()) {}
+    virtual ~StringFollower() {}
+    
+    /** Syntax used:
+        [n]         nth item in ParseList
+        'string'    'string' index in tuple
+        "string"    "string" index in tuple
+        lhs         Left side of a result (e.g. 'reason' in "reason=breakpoint-hit")
+        rhs         Right side of a result (e.g. 'breakpoint-hit' in "reason=breakpoint-hit")
+    */
+    virtual std::string follow(std::string path);
+};
+
+} // namespace GDB
+} // namespace Interface
+} // namespace Aesalon
+
+#endif
-- 
2.11.4.GIT