public static EXPRESSION parse(iSCOPE context)
{
Token token = get();
forget();
Span begin = token.span;
CONDITIONAL result = new CONDITIONAL();
EXPRESSION elsePart = null;
EXPRESSION condition = EXPRESSION.parse(null, context);
expect(TokenCode.Then);
EXPRESSION thenPart = EXPRESSION.parse(null, context);
COND_IF_THEN cit = new COND_IF_THEN(condition, thenPart);
condition.parent = result;
thenPart.parent = result;
cit.parent = result;
result.add(cit);
token = get();
while (true)
{
if (token.code == TokenCode.Elsif)
{
forget();
condition = EXPRESSION.parse(null, context);
expect(TokenCode.Then);
thenPart = EXPRESSION.parse(null, context);
cit = new COND_IF_THEN(condition, thenPart);
cit.setSpan(token.span, thenPart.span);
condition.parent = result;
thenPart.parent = result;
cit.parent = result;
result.add(cit);
token = get();
// go to next iteration
}
else
{
break;
}
}
token = expect(TokenCode.Else);
elsePart = EXPRESSION.parse(null, context);
elsePart.parent = result;
result.add(elsePart);
result.setSpan(begin, elsePart.span);
// context.add(result); ?? why ??
return(result);
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public static void parse(bool hidden, bool final, Token start, iSCOPE context)
{
Debug.Indent();
Debug.WriteLine("Entering CONSTANT.parse");
CONSTANT constant = new CONSTANT();
// 'const' and 'is' keywords were already parsed
Token token = get();
if (token.code == TokenCode.End)
{
forget(); goto FinalActions;
} // empty list
while (true)
{
EXPRESSION left = EXPRESSION.parse(null, context);
token = get();
if (token.code == TokenCode.DotDot) // range
{
forget();
EXPRESSION right = EXPRESSION.parse(null, context);
BINARY range = new BINARY(left, right);
range.setSpan(left.span, right.span);
range.parent = constant;
constant.constants.Add(range);
}
else // single expression
{
left.parent = constant;
constant.constants.Add(left);
}
token = get();
if (token.code == TokenCode.Comma)
{
forget(); continue;
}
if (token.code == TokenCode.End)
{
forget(); break;
}
else
{
error(token, "syntax-error"); break;
}
}
FinalActions:
constant.setSpecs(hidden, final);
context.add(constant);
constant.parent = context.self;
constant.setSpan(start, token);
Debug.WriteLine("Exiting CONSTANT.parse");
Debug.Unindent();
}
public static new EXPRESSION parse(Token first, iSCOPE context)
{
EXPRESSION result = ADDITIVE.parse(first, context);
Token token = get();
switch (token.code)
{
case TokenCode.Less:
case TokenCode.LessEqual:
case TokenCode.Greater:
case TokenCode.GreaterEqual:
case TokenCode.Equal:
case TokenCode.NotEqual:
case TokenCode.EqualEqual:
case TokenCode.NotEqualDeep:
forget(); break;
case TokenCode.In:
forget();
EXPRESSION left = EXPRESSION.parse(null, context);
token = get();
if (token.code == TokenCode.DotDot)
{
forget();
EXPRESSION right = EXPRESSION.parse(null, context);
RANGE_TYPE range = new RANGE_TYPE(left, right);
range.setSpan(left.span, right.span);
Span start = result.span;
IN_EXPRESSION r = new IN_EXPRESSION(token, result, range);
result.parent = r;
result = r;
result.setSpan(start, range.span);
goto Out;
}
else
{
// Something's wrong: right part of the in-expression
// should always be a range-type
goto Out;
}
default:
goto Out;
}
EXPRESSION second = ADDITIVE.parse(null, context);
Span start2 = result.span;
result = new RELATIONAL(token, result, second);
result.setSpan(start2, second.span);
Out:
return(result);
}
private static void parseVariant(LOOP result)
{
while (true)
{
EXPRESSION inv = EXPRESSION.parse(null, result);
if (inv == null)
{
return;
}
result.addv(inv);
inv.parent = result;
Token token = get();
if (token.code == TokenCode.Comma || wasEOL)
{
forget();
}
}
}
public static CALL parse(EXPRESSION reference, iSCOPE context)
{
CALL call = new CALL(reference);
Token token;
while (true)
{
EXPRESSION arg = EXPRESSION.parse(null, context);
call.add(arg);
token = get();
if (token.code == TokenCode.Comma)
{
forget(); continue;
}
break;
}
token = expect(TokenCode.RParen);
call.setSpan(reference.span, token.span);
return(call);
}
/// <summary>
///
/// </summary>
/// <syntax>
/// Loop : while BooleanExpression
/// loop
/// [ invariant PredicateList ]
/// [ StatementList ]
/// [ variant PredicateList ]
/// end [ loop ]
///
/// | loop
/// [ invariant PredicateList ]
/// [ StatementList ]
/// [ variant PredicateList ]
/// [ while BooleanExpression ]
/// end [ loop ]
/// </syntax>
/// <returns></returns>
public static void parse(Token id, iSCOPE context)
{
Debug.Indent();
Debug.WriteLine("Entering LOOP.parse");
// If id != null, then 'id' is a loop label.
// ':' after label is already parsed.
LOOP loop = new LOOP();
Context.enter(loop);
Token token = get();
Token begin = token;
if (token.code == TokenCode.While)
{
forget();
loop.prefix = true;
EXPRESSION whileExpr = EXPRESSION.parse(null, context);
token = get();
if (token.code == TokenCode.Loop)
{
forget();
loop.addw(whileExpr);
whileExpr.parent = loop;
}
else // Syntax error
{
error(token, "no-loop");
}
token = get();
if (token.code == TokenCode.Invariant)
{
forget();
parseInvariant(loop);
}
BODY body = new BODY();
body.parent = loop;
loop.body = body;
Context.enter(body);
token = get();
BODY.parse(TokenCode.End, TokenCode.Variant, TokenCode.ERROR, body);
body.setSpan(token, get());
Context.exit();
token = get();
if (token.code == TokenCode.Variant)
{
forget();
parseVariant(loop);
}
}
else if (token.code == TokenCode.Loop)
{
loop.prefix = false;
forget();
token = get();
if (token.code == TokenCode.Invariant)
{
forget();
parseInvariant(loop);
}
BODY body = new BODY();
body.parent = loop;
loop.body = body;
Context.enter(body);
token = get();
BODY.parse(TokenCode.End, TokenCode.Variant, TokenCode.While, body);
body.setSpan(token, get());
Context.exit();
token = get();
if (token.code == TokenCode.Variant)
{
forget();
parseVariant(loop);
}
token = get();
if (token.code == TokenCode.While)
{
forget();
EXPRESSION whileExpr = EXPRESSION.parse(null, context);
loop.addw(whileExpr);
whileExpr.parent = loop;
}
}
else // Compiler error
{
error(token, "system-bug");
}
token = get();
if (token.code != TokenCode.End) // Syntax error
{
error(token, "no-end", "loop");
}
else
{
forget();
token = get();
if (token.code == TokenCode.Loop)
{
forget();
}
}
if (loop != null)
{
loop.setSpan(begin, token);
}
context.add(loop);
Context.exit();
Debug.WriteLine("Exiting LOOP.parse");
Debug.Unindent();
}
public static void parse(Token routineName, bool hidden, bool final, bool isOverride, int pure_safe, iSCOPE context)
{
ROUTINE routine = null;
if (routineName.code == TokenCode.Init)
{
Debug.Indent();
Debug.WriteLine("Entering INITIALIZER.parse");
routine = new INITIALIZER();
goto Init;
}
Debug.Indent();
Debug.WriteLine("Entering ROUTINE.parse (" + routineName.image + ")");
string image = routineName.image;
Token token = get(); // What's after the routine name?
switch (routineName.image)
{
case "and":
if (token.code == TokenCode.Then)
{
forget();
image += " then";
Span span = new Span(routineName.span, token.span);
routineName = new Token(span, TokenCode.Identifier, image, new Category(CategoryCode.identifier));
}
break;
case "or":
token = get();
if (token.code == TokenCode.Else)
{
forget();
image += " else";
Span span = new Span(routineName.span, token.span);
routineName = new Token(span, TokenCode.Identifier, image, new Category(CategoryCode.identifier));
}
break;
}
routine = new ROUTINE(pure_safe, isOverride, routineName);
Init:
routine.setSpecs(hidden, final);
Context.enter(routine);
if (routineName.code == TokenCode.Init)
{
goto Init2;
}
token = get();
if (token.code == TokenCode.Alias)
{
forget();
token = expect(TokenCode.Identifier);
routine.alias = new IDENTIFIER(token.image);
}
if (token.code == TokenCode.LBracket)
{
// Generic routine
forget();
while (true)
{
var generic = FORMAL_GENERIC.parse(context);
routine.add(generic);
token = get();
switch (token.code)
{
case TokenCode.Comma:
case TokenCode.Semicolon: forget(); continue;
case TokenCode.RBracket: forget(); goto Finish;
default: { /* Syntax error */ break; }
}
}
Finish:
;
}
Init2:
token = get();
if (token.code == TokenCode.LParen)
{
forget(); token = get();
if (token.code == TokenCode.RParen)
{
// Empty parameter list
forget();
goto Weiter;
}
while (true)
{
VARIABLE.parse(false, false, false, false, null, null, routine);
token = get();
if (token.code == TokenCode.Comma)
{
forget(); continue;
}
if (token.code == TokenCode.Semicolon)
{
forget(); continue;
}
break;
}
expect(TokenCode.RParen);
}
Weiter:
token = get();
if (token.code == TokenCode.Colon)
{
forget();
bool ref_val, conc; // TEMP SOLUTION
Span span2;
routine.type = VARIABLE.parseTypeSpecifier(routine, out ref_val, out conc, out span2);
if (routine.type != null)
{
routine.type.parent = routine;
routine.type.setSpan(span2);
}
}
token = get();
if (token.code == TokenCode.Require)
{
forget(); token = get();
if (token.code == TokenCode.Else)
{
forget(); routine.requireElse = true;
}
while (true)
{
EXPRESSION precondition = EXPRESSION.parse(null, routine);
routine.addPre(precondition);
precondition.parent = routine;
token = get();
if (token.code == TokenCode.Is || token.code == TokenCode.Arrow)
{
break;
}
}
}
if (token.code == TokenCode.Arrow)
{
forget();
BODY body = new BODY();
routine.routineBody = body;
body.parent = routine;
Context.enter(body);
EXPRESSION expression = EXPRESSION.parse(null, body);
RETURN ret = new RETURN(expression);
expression.parent = ret;
ret.setSpan(expression.span);
ret.parent = body;
body.add(ret);
body.setSpan(ret.span);
Context.exit();
}
else if (token.code == TokenCode.Is)
{
forget(); token = get();
if (token.code == TokenCode.Abstract)
{
forget();
routine.isAbstract = true;
}
else if (token.code == TokenCode.Foreign)
{
forget();
routine.isForeign = true;
}
else
{
BODY body = new BODY();
body.parent = routine;
routine.routineBody = body;
Context.enter(body);
BODY.parse(TokenCode.End, TokenCode.Ensure, TokenCode.ERROR, body);
Context.exit();
}
token = get();
if (token.code == TokenCode.Ensure)
{
forget();
token = get();
if (token.code == TokenCode.Then)
{
forget(); routine.ensureThen = true;
}
ENTITY.weAreWithinEnsure = true;
while (true)
{
EXPRESSION postcondition = EXPRESSION.parse(null, routine);
routine.addPre(postcondition);
postcondition.parent = routine;
token = get();
if (token.code == TokenCode.End)
{
forget(); break;
}
}
ENTITY.weAreWithinEnsure = false;
}
else if (!routine.isAbstract && !routine.isForeign)
{
expect(TokenCode.End);
}
}
token = get();
if (token.code == TokenCode.Semicolon)
{
forget();
}
Context.exit();
context.add(routine);
routine.parent = context.self;
routine.setSpan(routineName, token);
if (routineName.code == TokenCode.Init)
{
Debug.WriteLine("Exiting INITIALIZER.parse");
}
else
{
Debug.WriteLine("Exiting ROUTINE.parse");
}
Debug.Unindent();
}
/// <summary>
///
/// </summary>
/// <syntax>
/// UnitTypeName : CompoundName [ GenericInstantiation ]
///
/// GenericInstantiation : "[" (Type|Expression) { "," (Type|Expression) } "]"
/// </syntax>
/// <returns></returns>
public static UNIT_REF parse(Token id, bool opt, iSCOPE context)
{
Debug.Indent();
Debug.WriteLine("Entering UNIT_REF.parse");
Token token = null;
// We assume that 'id' is 'identifier'.
if (id == null)
{
token = get(); forget();
}
else
{
token = id;
}
token = IDENTIFIER.parseCompoundName(token);
if (token == null) /* an error was detected earlier */ return {
(null);
}
Token start = token;
UNIT_REF unit_ref = new UNIT_REF(token.image);
unit_ref.opt = opt;
unit_ref.as_sign = true;
DECLARATION unit = Context.find(token);
if (unit != null && (unit is UNIT || unit is FORMAL_TYPE))
{
unit_ref.unit_ref = unit;
}
token = get();
if (token.code == TokenCode.LBracket)
{
forget();
while (true)
{
TYPE type = null;
token = get();
if (token.code == TokenCode.LParen)
{
type = TUPLE_TYPE.parse(context);
unit_ref.add(type);
goto Delimiter;
}
EXPRESSION expr = EXPRESSION.parse(null, context);
if (expr is REFERENCE || expr is UNRESOLVED)
{
string name = null;
if (expr is REFERENCE)
{
if ((expr as REFERENCE).declaration is UNIT)
{
name = (expr as REFERENCE).declaration.name.identifier;
}
else
{
goto NonType;
}
}
else // UNRESOLVED
{
name = (expr as UNRESOLVED).name.identifier;
}
id = new Token(expr.span, TokenCode.Identifier, name, new Category(CategoryCode.identifier));
type = UNIT_REF.parse(id, false, context); // Recursive call
unit_ref.add(type);
type.parent = unit_ref;
goto Delimiter;
}
// else -- expr is perhaps a non-type argument
NonType:
token = get();
if (token.code == TokenCode.DotDot)
{
// This is actually a range _type_
forget();
EXPRESSION right = EXPRESSION.parse(null, context);
RANGE_TYPE range = new RANGE_TYPE(expr, right);
range.setSpan(expr.span, right.span);
unit_ref.add(range);
range.parent = unit_ref;
}
else // Definitely a non-type argument
{
unit_ref.add(expr);
expr.parent = unit_ref;
}
Delimiter:
token = get();
switch (token.code)
{
case TokenCode.Comma: forget(); continue;
case TokenCode.RBracket: forget(); goto Finish;
default: { /* Syntax error in generic actuals */ break; }
}
}
Finish:
unit_ref.setSpan(start.span, token.span);
}
else
{
unit_ref.setSpan(start);
}
Debug.WriteLine("Exiting UNIT_REF.parse");
Debug.Unindent();
return(unit_ref);
}
/// <summary>
///
/// </summary>
/// <returns></returns>
new public static TUPLE_TYPE parse(iSCOPE context)
{
Debug.Indent();
Debug.WriteLine("Entering TUPLE_TYPE.parse");
TUPLE_TYPE tuple = new TUPLE_TYPE();
Token begin = expect(TokenCode.LParen);
int count = 0;
Token token = get();
if (token.code == TokenCode.RParen)
{
// Empty tuple
forget(); goto OutLoop;
}
var ids = new List <Token>();
UNIT_REF unit_type;
while (true)
{
token = expect(TokenCode.Identifier);
Token delimiter = get();
switch (delimiter.code)
{
case TokenCode.Comma:
// Identifier is the current name in the list of fields
forget();
ids.Add(token);
continue;
case TokenCode.Colon:
// Identifier is the last name in the field of fields
forget();
ids.Add(token);
// Now we treat collected ids as names of tuple fields,
// and the construct following ':' as unit name.
unit_type = UNIT_REF.parse(null, false, context);
unit_type.parent = tuple;
foreach (Token id in ids)
{
if (tuple.exists(id.image)) // Error: duplicate name
{
}
else
{
tuple.add(id.image, unit_type);
}
}
token = get();
if (token.code == TokenCode.Is)
{
forget();
EXPRESSION expr = EXPRESSION.parse(null, context);
foreach (Token id in ids)
{
if (tuple.exists(id.image))
{
}
else
{
tuple.add(id.image, expr);
}
}
}
ids.Clear();
break;
case TokenCode.Is:
ids.Add(token);
// No explicit type for the field(s) but only initializer
forget();
EXPRESSION expr2 = EXPRESSION.parse(null, context);
foreach (Token id in ids)
{
if (tuple.exists(id.image)) // Error: duplicate name
{
}
else
{
tuple.add(id.image, expr2);
}
}
ids.Clear();
break;
case TokenCode.RParen:
case TokenCode.Semicolon:
forget();
Token stop = delimiter;
// ')': The end of the tuple type; this means that all previous ids were
// actually simple type names.
// ';': The end of the current part of the tuple type. Again, this means
// that all ids were type names.
// In both cases, field names were omitted, and we have to assign
// artifical names for those fields.
ids.Add(token);
foreach (Token id in ids)
{
unit_type = UNIT_REF.parse(id, false, context);
count++;
string n = "$" + count.ToString();
tuple.add(n, unit_type);
}
ids.Clear();
if (stop.code == TokenCode.Semicolon)
{
continue;
}
else
{
goto OutLoop;
}
case TokenCode.LBracket:
ids.Add(token);
// 'ids' collected before, are actually unit names:
// all of them before the last one, were simple names,
// and the last one is like 'name[...'.
foreach (Token id in ids)
{
unit_type = UNIT_REF.parse(id, false, context);
count++;
string n = "$" + count.ToString();
tuple.add(n, unit_type);
}
break;
} // switch
} // while
OutLoop:
tuple.setSpan(begin, token);
Debug.WriteLine("Exiting TUPLE_TYPE.parse");
Debug.Unindent();
return(tuple);
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public static new EXPRESSION parse(Token first, iSCOPE context)
{
EXPRESSION result = null;
Token token = (first == null) ? get() : first;
Token begin = token;
switch (token.code)
{
case TokenCode.This:
forget();
UNIT unit = Context.unit();
if (unit == null)
{
// Error message!
result = new THIS(null);
}
else
{
result = new THIS(unit);
result.setSpan(token);
}
break;
case TokenCode.Return:
if (!ENTITY.weAreWithinEnsure)
{
break;
}
forget();
ROUTINE routine = Context.routine();
if (routine == null)
{
} // error
else
{
result = new RETURN_EXPR(routine);
result.setSpan(token);
}
break;
case TokenCode.Old:
forget();
result = EXPRESSION.parse(null, context);
Span end = result.span;
OLD old = new OLD(result);
result.parent = old;
result = old;
result.setSpan(begin.span, end);
break;
case TokenCode.If:
result = CONDITIONAL.parse(context);
break;
case TokenCode.LParen:
forget();
Span start_tuple = token.span;
result = EXPRESSION.parse(null, context);
token = get();
if (token.code == TokenCode.Comma)
{
// Seems to be a tuple
forget();
TUPLE_EXPR tuple = new TUPLE_EXPR();
tuple.add(result);
while (true)
{
EXPRESSION expr = EXPRESSION.parse(null, context);
tuple.add(expr);
token = get();
if (token.code != TokenCode.Comma)
{
break;
}
forget();
}
result = tuple;
}
end = expect(TokenCode.RParen).span;
result.setSpan(token.span, end);
break;
case TokenCode.Identifier:
if (first == null)
{
forget(); ////// perhaps the same condition should be added for all cases?
}
DECLARATION d = Context.find(token);
if (d == null)
{
result = new UNRESOLVED(context, new IDENTIFIER(token));
}
else
{
result = new REFERENCE(d);
}
Token token2 = get();
if (token2.code == TokenCode.LBracket)
{
UNIT_REF unitRef = UNIT_REF.parse(token, false, context);
result = new NEW(unitRef);
result.setSpan(unitRef.span);
}
else
{
result.setSpan(token);
}
break;
case TokenCode.Integer:
case TokenCode.Real:
case TokenCode.String:
case TokenCode.Character:
result = new LITERAL(token.value, token.span, token.code);
result.setSpan(token);
forget();
break;
default:
return(null);
}
// result.setSpan(token);
return(result);
}
public static new EXPRESSION parse(Token first, iSCOPE context)
{
EXPRESSION result = PRIMARY.parse(first, context);
if (result == null)
{
return(null);
}
Span begin = result.span;
while (true)
{
Token token = get();
switch (token.code)
{
case TokenCode.Dot:
forget();
IDENTIFIER identifier;
token = get();
if (token.code == TokenCode.Init)
{
forget();
// Initializer call in full form
identifier = new IDENTIFIER(INITIALIZER.initName);
}
else if (token.code == TokenCode.Identifier)
{
forget();
identifier = new IDENTIFIER(token);
}
else // syntax error
{
identifier = new IDENTIFIER("ERROR");
}
result = new MEMBER(result, identifier);
result.setSpan(begin, token.span);
break;
case TokenCode.LParen:
forget();
result = new CALL(result);
while (true)
{
token = get();
if (token.code == TokenCode.RParen)
{
forget(); break;
}
EXPRESSION actual = EXPRESSION.parse(null, context);
(result as CALL).add(actual);
token = get();
if (token.code == TokenCode.Comma)
{
forget(); continue;
}
token = expect(TokenCode.RParen);
break;
}
result.setSpan(begin, token.span);
break;
default:
goto Out;
}
}
Out:
return(result);
}
/// <summary>
/// The function processes all kinds of statements including
/// assignments, calls, and variable/constant declarations.
/// </summary>
/// <param name="context"></param>
/// <returns>true, if any construct (a statement, or a simple declaration)
/// was processed, and false otherwise.</returns>
public static bool parse(iSCOPE context, TokenCode stop1, TokenCode stop2, TokenCode stop3)
{
Debug.Indent();
Debug.WriteLine("Entering STATEMENT.parse");
bool result = true;
Token token = get();
Token begin = token;
if (token.code == stop1 && stop1 != TokenCode.ERROR)
{
goto Finish;
}
if (token.code == stop2 && stop2 != TokenCode.ERROR)
{
goto Finish;
}
if (token.code == stop3 && stop3 != TokenCode.ERROR)
{
goto Finish;
}
switch (token.code)
{
// case TokenCode.Pure: -- doesn't make any sense
case TokenCode.Safe:
case TokenCode.Routine:
ROUTINE.parse(token, false, false, false, 0, context);
break;
case TokenCode.If:
IF.parse(context);
break;
case TokenCode.While:
case TokenCode.Loop:
LOOP.parse(null, context);
break;
// Break
// : break [ Label ]
//
// Label
// : Identifier
case TokenCode.Break:
BREAK.parse(context);
break;
// Statement
// : ...
// | raise [ Expression ]
case TokenCode.Raise:
forget();
RAISE.parse(token.span, context);
break;
// Statement
// : ...
// | check PredicatesList end
// | ...
case TokenCode.Check:
CHECK.parse(context);
break;
// Statement
// : ...
// | return [ Expression ]
// | ...
case TokenCode.Return:
forget();
EXPRESSION expr = EXPRESSION.parse(null, context); // can be null
RETURN ret = new RETURN(expr);
if (expr != null)
{
expr.parent = ret;
ret.setSpan(begin.span, expr.span);
}
else
{
ret.setSpan(begin);
}
context.add(ret);
break;
// Statement
// : ...
// | Try
// | ...
//
// Try
// : try { Statement } Catches [ Else ] end
//
// Catches
// : catch [ "(" [ Identifier ":" ] Type ")" ] { Statement }
//
// Else
// : else { Statement }
case TokenCode.Try:
TRY.parse(context);
break;
// Statement
// : ...
// | ? Identifier
// | ...
//
case TokenCode.Question:
break;
case TokenCode.Init:
// Initializer call
forget();
Token start = token;
DECLARATION init = Context.find(INITIALIZER.initName);
EXPRESSION initRef;
if (init != null)
{
initRef = new REFERENCE(init);
}
else
{
initRef = new UNRESOLVED(context, new IDENTIFIER(INITIALIZER.initName));
}
CALL call = new CALL(initRef);
token = expect(TokenCode.LParen);
while (true)
{
EXPRESSION argument = EXPRESSION.parse(null, context);
call.add(argument);
argument.parent = call;
token = get();
if (token.code == TokenCode.Comma)
{
forget(); continue;
}
break;
}
token = expect(TokenCode.RParen);
call.setSpan(start.span, token.span);
context.add(call);
break;
case TokenCode.Identifier:
{
// Several different cases:
// - a label in front of while/loop
// - a declaration
// - a statement
forget();
Token next = get();
if (next.code == TokenCode.LParen)
{
forget();
TokenCode codeAfter = saveTokensUntilRightParenth(next);
switch (codeAfter)
{
case TokenCode.Colon:
case TokenCode.Is:
// case TokenCode.Do:
case TokenCode.Arrow:
//This as a routine declaration!!
ROUTINE.parse(token, false, false, false, 0, context);
goto Weiter;
}
}
EXPRESSION attempt = EXPRESSION.parse(token, context);
if (attempt is UNRESOLVED)
{
// Might be a label or a declaration...
Token idd = new Token(attempt.span, TokenCode.Identifier,
(attempt as UNRESOLVED).name.identifier,
new Category(CategoryCode.identifier));
token = get();
switch (token.code)
{
case TokenCode.Is:
case TokenCode.Comma:
// This is definitely a declaration
forget();
VARIABLE.parse(false, false, false, false, idd, token, context);
goto Weiter;
case TokenCode.Colon:
forget();
Token token2 = get();
if (token2.code == TokenCode.While || token2.code == TokenCode.Loop)
{
// This is a real label! Don't 'forget()'.
LOOP.parse(idd, context);
}
else
{
// This is definitely a variable declaration.
// Don't forget()
VARIABLE.parse(false, false, false, false, idd, token, context);
}
goto Weiter;
default:
// Nothing to do; just going further
break;
}
}
// 'attempt' is something else: a call or the left part of an assignment
token = get();
if (token.code == TokenCode.Assign)
{
forget();
EXPRESSION right = EXPRESSION.parse(null, context);
ASSIGNMENT res = new ASSIGNMENT(attempt, right);
res.setSpan(attempt.span, right.span);
context.add(res);
}
else
{
if (!(attempt is CALL)) // something's wrong
{
result = false;
}
context.add(attempt);
}
Weiter:
break;
}
case TokenCode.Const:
// Something like
// const a is 5...
// OR
// const is a, b, ... end
forget(); token = get();
if (token.code == TokenCode.Is)
{
forget();
CONSTANT.parse(context);
}
else
{
VARIABLE.parse(false, false, true, false, null, null, context);
}
break;
default:
// Something else, e.g., (a... or this...
// Either a function call or an assignment.
//
// this := ...
// (if cond then a else b).f ...
// ^
EXPRESSION e = EXPRESSION.parse(null, context);
if (e == null)
{
// Either an error or just the end of statement sequence
result = false;
break;
}
token = get();
if (token.code == TokenCode.Assign)
{
forget();
EXPRESSION right = EXPRESSION.parse(null, context);
ASSIGNMENT assignment = new ASSIGNMENT(e, right);
assignment.setSpan(e.span, right.span);
context.add(assignment);
}
else
{
context.add(e);
}
break;
}
Finish:
Debug.WriteLine("Exiting STATEMENT.parse");
Debug.Unindent();
return(result);
}
/// <summary>
///
/// <syntax><code>
/// Объявление-переменных
/// : Список-идентификаторов [ : Спецификатор-типа ] is Выражение
/// | Список-идентификаторов : Спецификатор-типа
///
/// Спецификатор-типа
/// : [ ? | ref | val | concurrent ] Тип
/// | as Составное-имя
/// </code></syntax>
/// </summary>
/// <param name="id"></param>
/// <returns></returns>
public static void parse(bool hidden, bool ffinal, bool isConst, bool isOverride, Token id, Token afterId, iSCOPE context)
{
Debug.Indent();
Debug.WriteLine("Entering VARIABLE.parse");
TYPE type = null;
EXPRESSION initializer = null;
bool RefVal = false; // 'val' by default
bool Conc = false;
bool Abstr = false;
bool Foreign = false;
Token token = id;
Span final = null;
// If id==null, then we just start processing the declaration.
// In this case, always afterId==null.
//
// If id != null then it contains an identifier.
// In this case, afterId contains ':', ',' or 'is' - three
// options starting a declaration.
List <Token> identifiers = new List <Token>();
if (token == null)
{
// We just start parsing variable declaration
token = get(); forget();
identifiers.Add(token);
// Parsing the rest of identifiers in the list (if any)
while (true)
{
token = get();
if (token.code != TokenCode.Comma)
{
break;
}
forget();
token = expect(TokenCode.Identifier);
identifiers.Add(token);
}
}
else
{
if (afterId.code == TokenCode.Is)
{
// id is ...
identifiers.Add(id);
token = afterId;
}
else if (afterId.code == TokenCode.Colon)
{
// 'token' contains an identifier.
// Check what's after this identifier?
//
// id : ...
// ^
identifiers.Add(id);
token = afterId;
}
else if (afterId.code == TokenCode.Comma)
{
// 'token' contains an identifier,
// and comma goes after it (comma was parsed already).
//
// id, ...
// ^
identifiers.Add(id);
// Parsing the rest of the list of identifiers.
while (true)
{
token = expect(TokenCode.Identifier);
identifiers.Add(token);
if (token.code != TokenCode.Comma)
{
break;
}
forget();
}
}
else
{
// Syntax error
error(afterId, "syntax-error", "declaration");
}
}
// Here, we have parsed the list of identifiers.
// 'token' contains the token after the list.
// Only two valid options are ':' or 'is'.
if (token.code == TokenCode.Colon)
{
// Type is expected.
if (afterId == null)
{
forget();
}
type = parseTypeSpecifier(context, out RefVal, out Conc, out final);
token = get();
}
if (token.code == TokenCode.Is)
{
forget(); token = get();
if (token.code == TokenCode.Abstract)
{
forget();
Abstr = true;
final = token.span;
}
else if (token.code == TokenCode.Foreign)
{
forget();
Foreign = true;
final = token.span;
}
else
{
forget();
initializer = EXPRESSION.parse(token, context);
if (type == null)
{
// Type inference
// initializer.calculateType();
type = initializer.type;
}
final = initializer.span;
}
}
// Here, we have the list of identifiers, their type,
// and perhaps the initializer.
// Create the final node(s) for variable declaration(s)
// out of identifier(s), type and initializer.
foreach (Token ident in identifiers)
{
VARIABLE varDecl = new VARIABLE(new IDENTIFIER(ident), type, initializer);
varDecl.setSpecs(hidden, ffinal);
varDecl.setVarSpecs(isConst, isOverride, RefVal, Conc, Abstr, Foreign);
varDecl.setSpan(ident.span, final != null ? final : ident.span);
context.add(varDecl);
varDecl.parent = context.self;
if (type != null)
{
type.parent = varDecl;
}
if (initializer != null)
{
initializer.parent = varDecl;
}
}
Debug.WriteLine("Exiting VARIABLE.parse");
Debug.Unindent();
}