public void Invoke(ParserContext context)
{
// Retrieve the current token.
Token token = context.Stream.Current;
// Abstract the token's type.
TokenType type = token.Type;
// Skip unknown tokens for error recovery.
if (type == SyntaxAnalysis.TokenType.Unknown)
{
// Create the warning.
context.NoticeRepository.UnknownToken(token.Value);
// Skip token.
context.Stream.Skip();
// Return immediately.
return;
}
// Function definition or global variable.
else if (TokenIdentifier.IsPrimitiveType(type) || type == TokenType.SymbolBracketL)
{
// Peek the token after identifier.
Token afterIdentifier = context.Stream.Peek(2);
// Function definition.
if (type == TokenType.SymbolBracketL || afterIdentifier.Type == SyntaxAnalysis.TokenType.SymbolParenthesesL)
{
// Invoke the function parser.
Function function = new FunctionParser().Parse(context);
// Emit the function.
function.Emit(this.ModulePipeContext);
}
// Otherwise, global variable declaration.
else
{
// Invoke the global variable parser.
GlobalVar globalVariable = new GlobalVarParser().Parse(context);
// Emit the global variable.
globalVariable.Emit(this.ModulePipeContext);
}
}
// Struct definition.
else if (type == SyntaxAnalysis.TokenType.KeywordStruct)
{
// Invoke the struct parser.
StructDef @struct = new StructDefParser().Parse(context);
// Emit the struct construct.
@struct.Emit(this.ModulePipeContext);
}
// External definition.
else if (type == SyntaxAnalysis.TokenType.KeywordExternal)
{
// Invoke the external definition parser.
Extern @extern = new ExternParser().Parse(context);
// Emit the external definition.
@extern.Emit(this.ModulePipeContext);
}
// TODO: Enforce a single namespace definition per-file.
// Namespace definition.
else if (type == SyntaxAnalysis.TokenType.KeywordNamespace)
{
// Invoke the namespace definition parser.
Namespace @namespace = new NamespaceParser().Parse(context);
// Process the namespace definition reaction.
@namespace.Invoke(this.ModulePipeContext.Target);
}
// Directive.
else if (type == SyntaxAnalysis.TokenType.SymbolHash)
{
// Invoke the directive parser.
Directive directive = new DirectiveParser().Parse(context);
// Invoke the directive onto the symbol table.
directive.Invoke(context);
}
// Otherwise, throw an error.
else
{
throw new Exception("Unexpected top-level entity");
}
}
/// <summary>
/// Process the next sequence. Returns true
/// if the sequence was successfully processed.
/// </summary>
public bool Next()
{
// TODO: What if EOF token has not been processed itself?
// End reached.
if (stream.LastItem)
{
return(false);
}
// TODO: Finish fixing this, parsers overflowing (+1) because of this issue with the Program start (05/02/2019).
TokenType type = stream.Get().Type;
// Skip program start token.
if (type == TokenType.ProgramStart)
{
stream.Skip();
// Assign type as next token type, continue execution.
type = stream.Get().Type;
}
// Skip unknown tokens for error recovery.
if (type == TokenType.Unknown)
{
// TODO: Use error reporting.
Console.WriteLine("Warning: Skipping unknown token");
return(false);
}
// Function definition or global variable.
else if (TokenIdentifier.IsType(type))
{
// Peek the token after identifier.
Token afterIdentifier = stream.Peek(2);
// Function definition.
if (afterIdentifier.Type == TokenType.SymbolParenthesesL)
{
// Invoke the function parser.
Function function = new FunctionParser().Parse(stream);
// Emit the function.
function.Emit(Module.Source);
}
// Otherwise, global variable declaration.
else
{
// Invoke the global variable parser.
GlobalVar globalVariable = new GlobalVarParser().Parse(stream);
// Emit the global variable.
globalVariable.Emit(Module.Source);
}
}
// External definition.
else if (type == TokenType.KeywordExternal)
{
// Invoke the external definition parser.
Extern external = new ExternParser().Parse(stream);
// Emit the external definition.
external.Emit(Module.Source);
}
// Otherwise, top-level expression.
else
{
// Invoke the top-level expression parser.
Function exprDelegate = new TopLevelExprParser().Parse(stream);
// Emit the top-level expression.
exprDelegate.Emit(Module.Source);
}
// At this point, an entity was processed.
return(true);
}