diff --git a/Assignment 1/Program.cs b/Assignment 1/Program.cs
index 95902da..aa6e0af 100644
--- a/Assignment 1/Program.cs
+++ b/Assignment 1/Program.cs
@@ -71,7 +71,8 @@ namespace Assignment_1
printwords,
printwordcount,
set,
- reverse
+ reverse,
+ h
}
public void StartParsing(Stream source, bool dynamicInput = false)
{
@@ -125,6 +126,13 @@ namespace Assignment_1
case statements.reverse:
Reverse(source);
break;
+ case statements.h:
+ Console.WriteLine("Commands are: ");
+ foreach (var item in Enum.GetValues(typeof(statements)))
+ {
+ Console.WriteLine("\t{0}", ((statements)item).ToString());
+ }
+ break;
}
}
else Console.WriteLine("Failed parsing statement");
@@ -143,10 +151,9 @@ namespace Assignment_1
///
bool Append(Stream source, long lineStart = -1)
{
- // If it wasn't explicitly set, assume line starts the length of 'append ' before the current position
if (lineStart == -1)
{
- lineStart = source.Position - "append ".Length;
+ lineStart = GetLineStart(source, "append");
}
string key;
long keyEndPos = FindIdentifier(source, out key);
@@ -256,18 +263,13 @@ namespace Assignment_1
{
if(lineStart == -1)
{
- lineStart = source.Position - "set ".Length;
+ lineStart = GetLineStart(source, "set");
}
string identifier;
long identifierEndPos = FindIdentifier(source, out identifier);
- if (identifierEndPos < 0 || identifierEndPos == source.Position)
+ if (identifierEndPos <= source.Position + 1 )
{
- string fullLine = GetNextLine(source); // Grab a copy of the line to show the user
- // set x
- string errorMSG = " ^ could not identify object";
- Console.WriteLine(fullLine);
- Console.WriteLine(errorMSG);
- source.SetLength(source.Position);
+ WriteDebugLine(lineStart, "set ".Length, "???", source);
return false;
}
source.Position = identifierEndPos;
@@ -275,6 +277,7 @@ namespace Assignment_1
long expressionEndPos = FindExpression(source, out expression);
if (expressionEndPos < 0)
{
+ WriteDebugLine(lineStart, identifierEndPos, "failed parsing expression", source);
// Couldn't match expression
return false;
}
@@ -282,8 +285,7 @@ namespace Assignment_1
{
if (Symbols[identifier].Item2.HasFlag(VariableFlags.Reserved))
{
- Console.WriteLine("Error: Cannot assign to {0} as it is a reserved constant.", identifier);
- source.SetLength(source.Position); // Wipe the remainder of the stream, so that it doesn't get read
+ WriteDebugLine(lineStart, identifierEndPos - identifier.Length, "cannot assign to a reserved constant", source);
return false;
}
Symbols[identifier] = new Tuple(expression, Symbols[identifier].Item2);
@@ -331,11 +333,29 @@ namespace Assignment_1
{
source.Position = lineStart;
string fullLine = GetNextLine(source);
- string errorMSG = new string (' ', (int)(caratPos - lineStart)) + "^ " + errorMessage;
+ string errorMSG = new string (' ', (caratPos - lineStart) >= 0 ? (int)(caratPos - lineStart):0) + "^ " + errorMessage;
Console.WriteLine(fullLine);
Console.WriteLine(errorMSG);
source.SetLength(source.Position);
}
+ ///
+ /// Gets the starting point of the expression at expected line.
+ ///
+ ///
+ ///
+ ///
+ long GetLineStart(Stream source, string word)
+ {
+ // Decrement and check the previous value is 32 (space), before incrementing back to our current pos
+ // Don't need to guard against oob - implied it's within bounds by the set command being at least 3 bytes long
+ source.Position--;
+ if (source.ReadByte() == 32)
+ {
+ source.Position--;
+ }
+ //source.Position++;
+ return source.Position - word.Length;
+ }
#endregion
#region Data Handling
@@ -507,7 +527,18 @@ namespace Assignment_1
///
static long FindNextWord(Stream s, out string nextWord)
{
- return FindNextOccurance(s, (c, s) => Char.IsWhiteSpace(c), out nextWord);
+ // Find the next occurance of a whitespace character
+ long originalPos = s.Position;
+ string tempstring;
+ long nextWSOccurance = FindNextOccurance(s, (c, s) => Char.IsWhiteSpace(c), out tempstring);
+ while (tempstring.Length == 0)
+ {
+ nextWSOccurance = FindNextOccurance(s, (c, s) => Char.IsWhiteSpace(c), out tempstring);
+ s.Position++;
+ }
+ nextWord = tempstring;
+ s.Position = originalPos;
+ return nextWSOccurance;
}
@@ -532,12 +563,6 @@ namespace Assignment_1
}
else if (p(nextChar, s))
{
- /*if (c == '\n')
- {
- s.Position--;
- if (s.ReadByte() != '\r') s.Position--;
- // Avoid capturing the carriage return
- }*/
charFound = true;
}
else