/// <summary>
/// program-heading :: "program" identifier [ '(' program-parameter-list ')' ] .
/// program-block :: block .
/// </summary>
/// <returns>A compiled program.</returns>
private ICompiledProgramPart ParseProgramHeading()
{
// "PROGRAM".
ExpectAndEat(TokenCode.TOK_KEY_PROGRAM, "The 'PROGRAM' key word expected.");
// An identifier.
Expect(TokenCode.TOK_IDENT, "A program name expected.");
var program = new CompiledProgramParts.Program(Tokenizer.CurrentToken.StringValue);
// program-parameter-list?
var t = Tokenizer.NextToken();
if (t.TokenCode == TokenCode.TOK_LBRA)
{
// Eat '('.
Tokenizer.NextToken();
ParseProgramParameterList(program);
// ')'.
ExpectAndEat(TokenCode.TOK_RBRA, "The end of program parameter list ')' expected.");
}
return(program);
}
/// <summary>
/// program-parameter-list :: identifier-list .
/// identifier-list :: identifier { ',' identifier } .
/// </summary>
private void ParseProgramParameterList(CompiledProgramParts.Program program)
{
Expect(TokenCode.TOK_IDENT, "An external file descriptor identifier expected.");
var t = Tokenizer.CurrentToken;
while (t.TokenCode != TokenCode.TOK_EOF)
{
Expect(TokenCode.TOK_IDENT, "An external file descriptor identifier expected.");
program.AddExternalFileDescriptor(t.StringValue);
// Eat identifier.
t = Tokenizer.NextToken();
if (t.TokenCode == TokenCode.TOK_LIST_SEP)
{
// Eat ','.
t = Tokenizer.NextToken();
continue;
}
break;
}
}
