public Expr Parse(ParserContext context)
{
// Ensure current token is parentheses start.
context.Stream.EnsureCurrent(TokenType.SymbolParenthesesL);
// Peek at the next token.
Token peek = context.Stream.Peek();
// Lambda expresion.
if (TokenIdentifier.IsType(peek, context) || peek.Type == TokenType.SymbolParenthesesR)
{
// Delegate to the lambda expression parser.
return(new LambdaExprParser().Parse(context));
}
// Skip the parentheses start token.
context.Stream.Skip();
// Parse the expression.
Expr expr = new ExprParser().Parse(context);
// Ensure current token is parentheses end.
context.Stream.EnsureCurrent(TokenType.SymbolParenthesesR);
// Skip the parentheses end token.
context.Stream.Skip();
// Return the expression.
return(expr);
}
public List <Expr> Parse(ParserContext context)
{
// Create the resulting argument list.
List <Expr> arguments = new List <Expr>();
// Parse the next value.
Expr value = new ExprParser().Parse(context);
// Append value to the argument list.
arguments.Add(value);
// Capture the current token.
Token token = context.Stream.Current;
// Expect either a comma or pipe symbol.
if (token.Type != SyntaxAnalysis.TokenType.OperatorPipe && token.Type != SyntaxAnalysis.TokenType.SymbolComma)
{
throw new Exception($"Expected next token to be of type either comma symbol or pipe operator, but got '{token.Type}'");
}
// There is another value.
else if (token.Type == SyntaxAnalysis.TokenType.SymbolComma)
{
// Skip comma token.
context.Stream.Skip();
// Recursively invoke a new pipe args parser instance.
List <Expr> nextArguments = new PipeArgsParser().Parse(context);
// Append resulting arguments.
arguments.AddRange(nextArguments);
}
// Return the resulting argument list.
return(arguments);
}
public Expr Parse(ParserContext context)
{
// Ensure current return keyword.
context.Stream.EnsureCurrent(SyntaxAnalysis.TokenType.KeywordReturn);
// Skip over the return keyword.
context.Stream.Skip();
// Capture the current token.
Token token = context.Stream.Current;
// There is no return expression.
if (token.Type == SyntaxAnalysis.TokenType.SymbolSemiColon)
{
// Skip the semi-colon.
context.Stream.Skip();
// TODO: Should return void? Investigate.
// Return null as no expression/return value was captured.
return(null);
}
// Otherwise, invoke the expression parser.
Expr expr = new ExprParser().Parse(context);
// Ensure current is a semi-colon.
context.Stream.EnsureCurrent(SyntaxAnalysis.TokenType.SymbolSemiColon);
// Skip the semi-colon.
context.Stream.Skip();
// Return the expression.
return(expr);
}
public VarDeclareExpr Parse(ParserContext context)
{
// Parse the type.
Type type = new TypeParser().Parse(context);
// Create the variable declaration & link the type.
VarDeclareExpr declaration = new VarDeclareExpr(type, null);
// Invoke identifier parser.
string identifier = new IdentifierParser().Parse(context);
// Assign the name.
declaration.SetName(identifier);
// Capture current token.
Token token = context.Stream.Current;
// A value is being assigned.
if (token.Type == SyntaxAnalysis.TokenType.OperatorAssignment)
{
// Skip the assignment operator.
context.Stream.Skip();
// Parse value.
Expr value = new ExprParser().Parse(context);
// Assign value.
declaration.Value = value;
}
// Return the resulting declaration construct.
return(declaration);
}
public Expr Parse(TokenStream stream)
{
// Skip return keyword.
stream.Skip(TokenType.KeywordReturn);
// Look at the next token.
Token nextToken = stream.Peek();
// There is no return expression.
if (nextToken.Type == TokenType.SymbolSemiColon)
{
// Skip to the semi-colon.
stream.Skip(TokenType.SymbolSemiColon);
// Return null as no expression/return value was captured.
return(null);
}
// Otherwise, invoke the expression parser.
Expr expr = new ExprParser().Parse(stream);
// Consume semi-colon after the expression.
stream.Skip(TokenType.SymbolSemiColon);
return(expr);
}
public Expr Parse(TokenStream stream)
{
// Skip to parentheses start token.
stream.Skip(TokenType.SymbolParenthesesL);
// Parse the expression.
Expr expr = new ExprParser().Parse(stream);
// Skip to parentheses end token.
stream.Skip(TokenType.SymbolParenthesesR);
return(expr);
}
public ArrayExpr Parse(ParserContext context)
{
// Ensure current token is bracket start.
context.Stream.EnsureCurrent(TokenType.SymbolBracketL);
// Skip bracket start token.
context.Stream.Skip();
// Create the value buffer list.
List <Expr> values = new List <Expr>();
// Begin parsing values.
context.Stream.NextUntil(TokenType.SymbolBracketR, (Token token) =>
{
// Invoke expression parser.
Expr value = new ExprParser().Parse(context);
// Add the captured expression to the list.
values.Add(value);
// Capture current token.
Token current = context.Stream.Current;
// Ensure current token is either semi-colon or bracket end.
if (current.Type != TokenType.SymbolComma && current.Type != TokenType.SymbolBracketR)
{
throw new Exception($"Expected token in array expression to be of type comma or bracket end, but got '{current.Type}'");
}
// Skip comma token.
else if (current.Type == TokenType.SymbolComma)
{
context.Stream.Skip();
}
// Signal to update iterator to current token, since parsers where invoked.
return(true);
});
// Ensure current token is bracket end.
context.Stream.EnsureCurrent(TokenType.SymbolBracketR);
// Skip bracket end token.
context.Stream.Skip();
// Create the resulting array construct.
ArrayExpr arrayExpr = new ArrayExpr(this.type, values.ToArray());
// Return the resulting array construct.
return(arrayExpr);
}
public List <Expr> Parse(ParserContext context)
{
// Ensure current token is parentheses start.
context.Stream.EnsureCurrent(TokenType.SymbolParenthesesL);
// Skip parentheses start.
context.Stream.Skip();
// Create the argument list result.
List <Expr> args = new List <Expr>();
// Contains at least one argument.
if (context.Stream.Current.Type != TokenType.SymbolParenthesesR)
{
while (true)
{
// Invoke the expression parser to parse the argument.
Expr arg = new ExprParser().Parse(context);
// Append the parsed argument.
args.Add(arg);
// Capture the current token's type.
TokenType currentTokenType = context.Stream.Current.Type;
// Arguments ended.
if (currentTokenType == TokenType.SymbolParenthesesR)
{
break;
}
// Otherwise, expect a comma.
else if (currentTokenType != TokenType.SymbolComma)
{
throw new Exception("Unexpected token in function call argument list");
}
// Skip token.
context.Stream.Skip();
}
}
// Ensure current token is parentheses end.
context.Stream.EnsureCurrent(TokenType.SymbolParenthesesR);
// Skip parentheses end.
context.Stream.Skip();
return(args);
}
public Function Parse(TokenStream stream)
{
// TODO: Use expression? Maybe add it to the body block?
// Parse the expression.
Expr expr = new ExprParser().Parse(stream);
// Create the anonymous function.
var function = new Function();
// Set the function name to anonymous.
function.SetNameAnonymous();
// Create default prototype.
function.CreatePrototype();
// TODO: Finish implementing (continue Kaleidoscope tutorial).
Block body = function.CreateBody();
return(function);
}
public StructProperty Parse(ParserContext context)
{
// Invoke identifier parser.
string identifier = new IdentifierParser().Parse(context);
// Ensure current token is symbol colon.
context.Stream.EnsureCurrent(TokenType.SymbolColon);
// Skip colon symbol token.
context.Stream.Skip();
// Invoke expression parser to capture the value.
Expr value = new ExprParser().Parse(context);
// Create the resulting property construct.
StructProperty property = new StructProperty(identifier, value, this.index);
// Return the resulting property construct.
return(property);
}
public VarDeclareExpr Parse(TokenStream stream)
{
// Consume the type string.
var typeValue = stream.Next().Value;
// Create the type.
var type = new Type(typeValue);
// Create the variable declaration & link the type.
var declaration = new VarDeclareExpr(type, null);
// Consume the variable name.
var name = stream.Next().Value;
// Ensure captured name is not null nor empty.
if (string.IsNullOrEmpty(name))
{
throw new Exception("Unexpected variable declaration identifier to be null or empty");
}
// Assign the name.
declaration.SetName(name);
// Peek next token for value.
Token nextToken = stream.Peek();
// Value is being assigned.
if (nextToken.Type == TokenType.OperatorAssignment)
{
// Skip over the Assignment operator
stream.Skip();
// Parse value.
Expr value = new ExprParser().Parse(stream);
// Assign value.
declaration.Value = value;
}
return(declaration);
}
public List <Expr> Parse(TokenStream stream)
{
// Create the argument list result.
var args = new List <Expr>();
// Contains at least one argument.
if (stream.Get().Type != TokenType.SymbolParenthesesL)
{
while (true)
{
// Invoke the expression parser to parse the argument.
Expr arg = new ExprParser().Parse(stream);
// Append the parsed argument.
args.Add(arg);
TokenType currentTokenType = stream.Get().Type;
// Arguments ended.
if (currentTokenType == TokenType.SymbolParenthesesR)
{
break;
}
// Otherwise, expect a comma.
else if (currentTokenType != TokenType.SymbolComma)
{
throw new Exception("Unexpected token in function call argument list");
}
// Skip token.
stream.Skip();
}
}
return(args);
}
