public Expression GetExpression(LsmContext lsmContext)
{
return Expression.IfThenElse(
LsmCommonExpressions.CharMatch(lsmContext, _constant),
Actions.GetExpression(lsmContext),
Expression.Empty());
}
public Expression GetExpression(LsmContext lsmContext)
{
return Expression.IfThenElse(
GetCharacterMatchExpression(lsmContext),
Actions.GetExpression(lsmContext),
Expression.Empty());
}
public Expression GetBodyExpression(LsmContext lsmContext)
{
return Expression.IfThenElse(
LsmCommonExpressions.EndOfStream(lsmContext),
PostStreamActions.GetExpression(lsmContext),
MatchRules.GetExpression(lsmContext));
}
public static Expression AcceptChar(LsmContext lsmContext)
{
return Expression.Call(
lsmContext.tokenTextVariable,
typeof(StringBuilder).GetMethod("Append", new[] { typeof(char) }),
lsmContext.currentCharVariable);
}
public static Expression AcceptToken(LsmContext lsmContext, int typeID)
{
return Expression.Call(
lsmContext.tokenListVariable,
typeof(List<LsmToken>).GetMethod("Add", new[] {typeof(LsmToken)}),
LsmCommonExpressions.NewToken(lsmContext, typeID));
}
public LsmTokenizeFunction BuildLexerFunction()
{
LsmContext context = new LsmContext();
LabelTarget breakTarget = Expression.Label();
Expression block = Expression.Block(
context.GetLocalVariables(),
context.GetInitializationBlock(StartState.ID),
Expression.Loop(
Expression.Block(
LsmCommonExpressions.AssignPeekValue(context),
Expression.IfThenElse(
LsmCommonExpressions.EndOfStream(context),
Expression.Empty(),
LsmCommonExpressions.AssignCurrentChar(context)),
States.GetExpression(context),
LsmCommonExpressions.UpdateCharIndexInState(context),
Expression.IfThenElse(
LsmCommonExpressions.EndOfStream(context),
Expression.Break(breakTarget),
Expression.Empty())),
breakTarget),
context.currentStateVariable);
Expression<LsmTokenizeFunction> finalExpression
= Expression.Lambda<LsmTokenizeFunction>(
block,
context.textReaderParameter,
context.tokenListVariable);
return finalExpression.Compile();
}
public static Expression CallCharMatchFunc(LsmContext lsmContext,
Func<char, bool> func)
{
return Expression.Call(
null,
func.Method,
lsmContext.currentCharVariable);
}
public Expression GetExpression(LsmContext lsmContext)
{
return Expression.IfThenElse(
LsmCommonExpressions.CallCharMatchFunc(
lsmContext, _matchFunc),
Actions.GetExpression(lsmContext),
Expression.Empty());
}
public Expression GetExpression(LsmContext lsmContext)
{
return Expression.IfThenElse(
Expression.Equal(
lsmContext.currentStateVariable,
Expression.Constant(this.ID)),
GetBodyExpression(lsmContext),
Expression.Empty());
}
public static Expression AlphaNumericMatch(LsmContext lsmContext)
{
return Expression.Call(
null,
typeof(char).GetMethod(
"IsLetterOrDigit",
new[] { typeof(char) }),
lsmContext.currentCharVariable);
}
public static Expression AssignCurrentChar(LsmContext lsmContext)
{
return Expression.Assign(
lsmContext.currentCharVariable,
Expression.Call(
null,
typeof(Convert).GetMethod("ToChar", new[] {typeof(int)}),
LsmCommonExpressions.PeekValue(lsmContext)));
}
public Expression GetExpression(LsmContext lsmContext)
{
return Expression.IfThenElse(
Expression.Equal(
lsmContext.charIndexInStateVariable,
Expression.Constant(_charIndex)),
Actions.GetExpression(lsmContext),
Expression.Empty());
}
public static Expression IfElseChain(IEnumerable<ILsmExpressable> expressableConditions,
Expression defaultExpression, LsmContext lsmContext)
{
List<ILsmExpressable> expressables = expressableConditions.Reverse().ToList();
ConditionalExpression lastOuterExpression = expressables[0].GetExpression(lsmContext)
as ConditionalExpression;
expressables.RemoveAt(0);
lastOuterExpression = Expression.IfThenElse(
lastOuterExpression.Test,
lastOuterExpression.IfTrue,
defaultExpression);
while (expressables.Count > 0)
{
ConditionalExpression outerExpression = expressables[0].GetExpression(lsmContext)
as ConditionalExpression;
lastOuterExpression = Expression.IfThenElse(outerExpression.Test,
outerExpression.IfTrue,
lastOuterExpression);
expressables.RemoveAt(0);
}
return lastOuterExpression;
}
public Expression GetExpression(LsmContext lsmContext)
{
return LsmCommonExpressions.AcceptToken(lsmContext, _tokenTypeID);
}
public static Expression WhiteSpaceMatch(LsmContext lsmContext)
{
return Expression.Call(
null,
typeof(char).GetMethod(
"IsWhiteSpace",
new[] { typeof(char) }),
lsmContext.currentCharVariable);
}
public Expression GetExpression(LsmContext lsmContext)
{
return LsmCommonExpressions.AcceptChar(lsmContext);
}
public static Expression UpdateCharIndexInState(LsmContext lsmContext)
{
return Expression.IfThenElse(
Expression.Equal(
lsmContext.currentStateVariable,
lsmContext.lastStateVariable),
Expression.PreIncrementAssign(lsmContext.charIndexInStateVariable),
Expression.Block(
Expression.Assign(
lsmContext.charIndexInStateVariable,
Expression.Constant(0)),
Expression.Assign(
lsmContext.lastStateVariable,
lsmContext.currentStateVariable)));
}
public Expression GetExpression(LsmContext lsmContext)
{
return LsmCommonExpressions.ChangeState(lsmContext, _newState.ID);
}
public static Expression CharMatch(LsmContext lsmContext, char constant)
{
return Expression.Equal(
lsmContext.currentCharVariable,
Expression.Constant(constant));
}
public Expression GetExpression(LsmContext lsmContext)
{
return Expression.Block(
LsmCommonExpressions.ReadChar(lsmContext),
LsmCommonExpressions.IncrementCharIndex(lsmContext));
}
public static Expression EndOfStream(LsmContext lsmContext)
{
return Expression.Equal(
lsmContext.peekValueVariable,
Expression.Constant(-1));
}
public Expression GetExpression(LsmContext lsmContext)
{
return LsmCommonExpressions.ClearTokenText(lsmContext);
}
public static Expression AssignPeekValue(LsmContext lsmContext)
{
return Expression.Assign(
lsmContext.peekValueVariable,
LsmCommonExpressions.PeekValue(lsmContext));
}
public static Expression IncrementCharIndex(LsmContext lsmContext)
{
return Expression.PostIncrementAssign(lsmContext.charIndexVariable);
}
public static Expression ChangeState(LsmContext context, int stateID)
{
return Expression.Assign(
context.currentStateVariable,
Expression.Constant(stateID));
}
public static Expression MarkTokenStart(LsmContext lsmContext)
{
return Expression.Assign(
lsmContext.tokenStartVariable,
lsmContext.charIndexVariable);
}
public static Expression ClearTokenText(LsmContext lsmContext)
{
return Expression.Call(
lsmContext.tokenTextVariable,
typeof(StringBuilder).GetMethod("Clear", Type.EmptyTypes));
}
public static Expression ReadChar(LsmContext lsmContext)
{
return Expression.Call(
lsmContext.textReaderParameter,
typeof(TextReader).GetMethod("Read", Type.EmptyTypes));
}
public static Expression NewToken(LsmContext lsmContext, int typeID)
{
return Expression.New(
typeof(LsmToken).GetConstructor(
new [] {typeof(int), typeof(string), typeof(int)}),
Expression.Constant(typeID),
LsmCommonExpressions.GetTokenText(lsmContext),
lsmContext.tokenStartVariable);
}
public Expression GetExpression(LsmContext lsmContext)
{
return LsmCommonExpressions.MarkTokenStart(lsmContext);
}
