public static bool IsDoubleQuote(LexerContext context)
{
return(!context.IsEnded() &&
!context.IsLast() &&
context.GetCurrentChar().Equals('\'') &&
context.GetNextChar().Equals('\''));
}
internal Token(LexerContext ctx, int index, TokenType type, string value)
{
this.ctx = ctx;
Index = index;
Type = type;
Value = value;
}
public static bool IsOctalNumberBegin(LexerContext context)
{
return(context.GetCurrentChar().Equals('&') &&
!context.IsEnded() &&
!context.IsLast() &&
OctalDigits.Contains(context.GetNextChar()));
}
public static bool IsDelphiCommentBegin(LexerContext context)
{
return(!context.IsEnded() &&
!context.IsLast() &&
context.GetCurrentChar().Equals('/') &&
context.GetNextChar().Equals('/'));
}
public static bool IsOldStyleCommentEnd(LexerContext context)
{
return(!context.IsEnded() &&
!context.IsLast() &&
context.GetCurrentChar().Equals('*') &&
context.GetNextChar().Equals(')'));
}
public static bool IsBinaryNumberBegin(LexerContext context)
{
return(context.GetCurrentChar().Equals('%') &&
!context.IsEnded() &&
!context.IsLast() &&
HexadecimalDigits.Contains(context.GetNextChar()));
}
public static bool IsNumberBegin(LexerContext context)
{
return(IsDecimalNumberBegin(context) ||
IsHexNumberBegin(context) ||
IsOctalNumberBegin(context) ||
IsBinaryNumberBegin(context));
}
public Token Lex(ISource source, int start)
{
using (var context = new LexerContext(source, start))
{
return(context.GetToken());
}
}
public static bool IsStringBegin(LexerContext context)
{
return(!context.IsEnded() &&
!context.IsLast() &&
(
context.GetCurrentChar().Equals('\'') && IsStringSymbol(context.GetNextChar()) ||
context.GetCurrentChar().Equals('#') && Char.IsDigit(context.GetNextChar())
));
}
/// <summary>
/// 指示当前对象是否等于同一类型的另一个对象。
/// </summary>
/// <param name="other">与此对象进行比较的对象。</param>
/// <returns>如果当前对象等于 <paramref name="other"/>，
/// 则为 <c>true</c>；否则为 <c>false</c>。</returns>
/// <overloads>
/// <summary>
/// 指示当前对象是否等于另一个对象。
/// </summary>
/// </overloads>
public bool Equals(LexerContext other)
{
if (object.ReferenceEquals(other, this))
{
return(true);
}
if (this.index != other.index)
{
return(false);
}
if (this.contextType != other.contextType)
{
return(false);
}
return(this.label == other.label);
}
/// <summary>
/// 指示当前对象是否等于同一类型的另一个对象。
/// </summary>
/// <param name="other">与此对象进行比较的对象。</param>
/// <returns>如果当前对象等于 <paramref name="other"/>，
/// 则为 <c>true</c>；否则为 <c>false</c>。</returns>
/// <overloads>
/// <summary>
/// 指示当前对象是否等于另一个对象。
/// </summary>
/// </overloads>
public bool Equals(LexerContext other)
{
if (object.ReferenceEquals(other, this))
{
return true;
}
if (this.index != other.index)
{
return false;
}
if (this.contextType != other.contextType)
{
return false;
}
return this.label == other.label;
}
/// <summary>
/// Restore a previously saved Lexer context.
/// https://github.com/TypeCobolTeam/TypeCobol/issues/1000
/// </summary>
public static void RestoreLexerContext()
{
if (UseStack.Count > 0)
{
LexerContext ctx = UseStack.Pop();
System.Console.In.Close();
System.Console.SetIn(ctx.In);
CurrentFile = ctx.CurrentFile;
current_line = ctx.CurrentLine;
current_position = ctx.CurrentPosition;
absolute_position = ctx.AbsolutePosition;
next_char = ctx.NextChar;
next_char2 = ctx.NextChar2;
next_char3 = ctx.NextChar3;
next_char4 = ctx.NextChar4;
}
}
/// <summary>
/// Switch the current lexer context to a new one.
/// https://github.com/TypeCobolTeam/TypeCobol/issues/1000
/// </summary>
/// <param name="filePath">The new file path</param>
/// <param name="sr">The new stream reader</param>
public static void SwitchLexerContext(string filePath, System.IO.StreamReader sr)
{
LexerContext ctx = new LexerContext();
ctx.FilePath = filePath;
ctx.In = System.Console.In;
ctx.CurrentFile = CurrentFile;
ctx.CurrentLine = current_line;
ctx.CurrentPosition = current_position;
ctx.AbsolutePosition = absolute_position;
ctx.NextChar = next_char;
ctx.NextChar2 = next_char2;
ctx.NextChar3 = next_char3;
ctx.NextChar4 = next_char4;
UseStack.Push(ctx);
System.Console.SetIn(sr);
current_line = 1;
current_position = 1;
absolute_position = 1;
CurrentFile = filePath;
InitLookaheads();
}
public static bool IsBinaryDigit(LexerContext context)
{
return(BinaryDigits.Contains(context.GetCurrentChar()));
}
public static bool IsHexadecimalDigit(LexerContext context)
{
return(HexadecimalDigits.Contains(context.GetCurrentChar()));
}
public static bool IsDecimalDigit(LexerContext context)
{
return(Char.IsDigit(context.GetCurrentChar()));
}
/// <summary>
/// Changes the lexer's current context.
/// </summary>
/// <param name="context">The lexer's new context.</param>
private static void ChangeContext(LexerContext context)
{
currentContext = context ?? cachedLexerContext_Default;
currentContext.Initialize();
}
public static bool IsCommentBegin(LexerContext context)
{
return(IsOldStyleCommentBegin(context) ||
IsTurboPascalCommentBegin(context) ||
IsDelphiCommentBegin(context));
}
public static bool IsTurboPascalCommentEnd(LexerContext context)
{
return(!context.IsEnded() &&
context.GetCurrentChar().Equals('}'));
}
public static bool IsIdentifierBegin(LexerContext context)
{
return(context.GetCurrentChar() == '_' || Char.IsLetter(context.GetCurrentChar()));
}
public static bool IsSpecialPair(LexerContext context)
{
return(SpecialPairs.Contains(context.GetCharPair()));
}
public Token Lex(ISource source, int start)
{
var context = new LexerContext(source, start, Cache);
return(context.GetToken());
}
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/** The actual routine to return one Symbol. This is normally called from
* next_token(), but for debugging purposes can be called indirectly from
* debug_next_token().
*/
protected static Symbol real_next_token()
{
int sym_num;
for (;;)
{
/* look for white space */
if (next_char == ' ' || next_char == '\t' || next_char == '\n' ||
next_char == '\f' || next_char == '\r')
{
/* advance past it and try the next character */
advance();
continue;
}
/* look for a single character symbol */
sym_num = find_single_char(next_char);
if (sym_num != -1)
{
/* found one -- advance past it and return a Symbol for it */
advance();
return(new Symbol(sym_num));
}
/* look for : or ::= */
if (next_char == ':')
{
/* if we don't have a second ':' return COLON */
if (next_char2 != ':')
{
advance();
return(new Symbol(sym.COLON));
}
/* move forward and look for the '=' */
advance();
if (next_char2 == '=')
{
advance(); advance();
return(new Symbol(sym.COLON_COLON_EQUALS));
}
else
{
/* return just the colon (already consumed) */
return(new Symbol(sym.COLON));
}
}
/* find a "%prec" string and return it. otherwise, a '%' was found,
* which has no right being in the specification otherwise */
if (next_char == '%')
{
advance();
if ((next_char == 'p') && (next_char2 == 'r') && (next_char3 == 'e') &&
(next_char4 == 'c'))
{
advance();
advance();
advance();
advance();
return(new Symbol(sym.PERCENT_PREC));
}
else
{
emit_error("Found extraneous percent sign");
}
}
/* look for a comment */
if (next_char == '/' && (next_char2 == '*' || next_char2 == '/'))
{
/* swallow then continue the scan */
swallow_comment();
continue;
}
/* look for start of code string */
if (next_char == '{' && next_char2 == ':')
{
return(do_code_string());
}
/* look for an id or keyword */
if (id_start_char(next_char))
{
return(do_id());
}
if (next_char == '#' && current_position == 1 && (next_char2 == 'u') && (next_char3 == 's') &&
(next_char4 == 'e'))
{ //https://github.com/TypeCobolTeam/TypeCobol/issues/1000
//#use directive must appears as the first character in the line.
//Read the whole line after the #use directive and trim it as being the file path to be included.
string useLine = System.Console.In.ReadLine();
current_line += 1;
lexer.InitLookaheads();
return(LexerContext.HandleUseDirective(useLine?.Trim()));
}
/* look for EOF */
if (next_char == EOF_CHAR)
{
return(new Symbol(sym.EOF));
}
/* if we get here, we have an unrecognized character */
emit_warn("Unrecognized character '" +
next_char + "'(" + next_char +
") -- ignored");
/* advance past it */
advance();
}
}
public static bool IsSpecial(LexerContext context)
{
return(SpecialCharacters.Contains(context.GetCurrentChar()));
}
