private static AstNode ParseClass (TokenStream stream)
{
stream.Expect (TokenClass.Keyword, "class");
string name = stream.Expect (TokenClass.Identifier).Value;
List<string> baseClass = new List<string> ();
if (stream.Accept (TokenClass.Colon)) {
do {
baseClass.Add (ParseClassName (stream));
} while (stream.Accept (TokenClass.Comma));
}
ClassDeclaration clazz = new ClassDeclaration (stream.Location, name, baseClass);
stream.Expect (TokenClass.OpenBrace);
while (!stream.Match (TokenClass.CloseBrace)) {
if (stream.Match (TokenClass.Keyword, "func") || stream.Match (TokenClass.Operator,
"@")) {
FunctionDeclaration func = ParseFunction (stream, false, clazz) as FunctionDeclaration;
if (func.Name == name) {
clazz.Constructor = func;
} else {
clazz.Add (func);
}
} else {
clazz.Add (ParseStatement (stream));
}
}
stream.Expect (TokenClass.CloseBrace);
return clazz;
}
public static AstNode ParseAdditive(TokenStream stream)
{
AstNode expr = ParseMultiplicative (stream);
while (stream.Match (TokenClass.Operator)) {
switch (stream.Current.Value) {
case "+":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Add, expr,
ParseMultiplicative (stream));
continue;
case "-":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Sub, expr,
ParseMultiplicative (stream));
continue;
default:
break;
}
break;
}
return expr;
}
private static AstNode ParseBlock(TokenStream stream)
{
CodeBlock ret = new CodeBlock (stream.Location);
stream.Expect (TokenClass.OpenBrace);
while (!stream.Match (TokenClass.CloseBrace)) {
ret.Add (ParseStatement (stream));
}
stream.Expect (TokenClass.CloseBrace);
return ret;
}
public static AstNode ParseMulDivMod(TokenStream stream)
{
AstNode expr = ParseUnary (stream);
while (stream.Match (TokenClass.Operator)) {
switch (stream.Current.Value) {
case "*":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Mul, expr,
ParseUnary (stream));
continue;
case "/":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Div, expr,
ParseUnary (stream));
continue;
case "%":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Mod, expr,
ParseUnary (stream));
continue;
default:
break;
}
break;
}
return expr;
}
private static string ParseModuleName(TokenStream stream)
{
Token initIdent = stream.Expect (TokenClass.Identifier);
if (stream.Match (TokenClass.Operator, ".")) {
StringBuilder accum = new StringBuilder ();
accum.Append (initIdent.Value);
while (stream.Accept (TokenClass.Operator, ".")) {
Token ident = stream.Expect (TokenClass.Identifier);
accum.Append (Path.DirectorySeparatorChar);
accum.Append (ident.Value);
}
return accum.ToString ();
} else {
return initIdent.Value;
}
}
private static AstNode ParseInterface(TokenStream stream)
{
stream.Expect (TokenClass.Keyword, "interface");
string name = stream.Expect (TokenClass.Identifier).Value;
InterfaceDeclaration contract = new InterfaceDeclaration (stream.Location, name);
stream.Expect (TokenClass.OpenBrace);
while (!stream.Match (TokenClass.CloseBrace)) {
if (stream.Match (TokenClass.Keyword, "func")) {
FunctionDeclaration func = ParseFunction (stream, true) as FunctionDeclaration;
contract.Add (func);
} else {
stream.ErrorLog.AddError (ErrorType.ParserError, stream.Location,
"Interface may only contain function prototypes!");
}
while (stream.Accept (TokenClass.SemiColon));
}
stream.Expect (TokenClass.CloseBrace);
return contract;
}
private static AstNode ParseGiven(TokenStream stream)
{
GivenStatement switchStmt = new GivenStatement (stream.Location);
stream.Expect (TokenClass.Keyword, "given");
stream.Expect (TokenClass.OpenParan);
switchStmt.Add (ParseExpression (stream));
stream.Expect (TokenClass.CloseParan);
stream.Expect (TokenClass.OpenBrace);
AstNode defaultBlock = new AstRoot (stream.Location);
AstRoot caseStatements = new AstRoot (stream.Location);
while (!stream.EndOfStream && !stream.Match (TokenClass.CloseBrace)) {
caseStatements.Add (ParseWhen (stream));
if (stream.Accept (TokenClass.Keyword, "default")) {
defaultBlock = ParseStatement (stream);
}
}
switchStmt.Add (caseStatements);
switchStmt.Add (defaultBlock);
stream.Expect (TokenClass.CloseBrace);
return switchStmt;
}
private static AstNode ParseEnum(TokenStream stream)
{
stream.Expect (TokenClass.Keyword, "enum");
string name = stream.Expect (TokenClass.Identifier).Value;
EnumDeclaration decl = new EnumDeclaration (stream.Location, name);
stream.Expect (TokenClass.OpenBrace);
int defaultVal = -1;
while (!stream.Match (TokenClass.CloseBrace)) {
string ident = stream.Expect (TokenClass.Identifier).Value;
if (stream.Accept (TokenClass.Operator, "=")) {
string val = stream.Expect (TokenClass.IntLiteral).Value;
int numVal = 0;
if (val != "") {
numVal = Int32.Parse (val);
}
decl.Items [ident] = numVal;
} else {
decl.Items [ident] = defaultVal--;
}
if (!stream.Accept (TokenClass.Comma)) {
break;
}
}
stream.Expect (TokenClass.CloseBrace);
return decl;
}
private static UseStatement ParseUse(TokenStream stream)
{
stream.Expect (TokenClass.Keyword, "use");
bool relative = stream.Accept (TokenClass.Operator, ".");
string ident = "";
if (!stream.Match (TokenClass.Operator, "*"))
ident = ParseModuleName (stream);
if (stream.Match (TokenClass.Keyword, "from") || stream.Match (TokenClass.Comma) ||
stream.Match (TokenClass.Operator, "*")) {
List<string> items = new List<string> ();
bool wildcard = false;
if (!stream.Accept (TokenClass.Operator, "*")) {
items.Add (ident);
stream.Accept (TokenClass.Comma);
while (!stream.Match (TokenClass.Keyword, "from")) {
Token item = stream.Expect (TokenClass.Identifier);
items.Add (item.Value);
if (!stream.Accept (TokenClass.Comma)) {
break;
}
}
} else {
wildcard = true;
}
stream.Expect (TokenClass.Keyword, "from");
relative = stream.Accept (TokenClass.Operator, ".");
string module = ParseModuleName (stream);
return new UseStatement (stream.Location, module, items, wildcard, relative);
}
return new UseStatement (stream.Location, ident, relative);
}
private static ArgumentList ParseTypeList(TokenStream stream)
{
ArgumentList argList = new ArgumentList (stream.Location);
while (!stream.Match (TokenClass.CloseParan)) {
argList.Add (ParseExpression (stream));
if (!stream.Accept (TokenClass.Comma)) {
break;
}
}
return argList;
}
private static AstNode ParseTuple(AstNode firstVal, TokenStream stream)
{
TupleExpression tuple = new TupleExpression (stream.Location);
tuple.Add (firstVal);
while (!stream.Match (TokenClass.CloseParan)) {
tuple.Add (ParseExpression (stream));
if (!stream.Accept (TokenClass.Comma)) {
break;
}
}
stream.Expect (TokenClass.CloseParan);
return tuple;
}
private static AstNode ParseStatement(TokenStream stream)
{
if (stream.Match (TokenClass.Keyword)) {
switch (stream.Current.Value) {
case "class":
return ParseClass (stream);
case "enum":
return ParseEnum (stream);
case "interface":
return ParseInterface (stream);
case "func":
return ParseFunction (stream);
case "if":
return ParseIf (stream);
case "given":
return ParseGiven (stream);
case "for":
return ParseFor (stream);
case "foreach":
return ParseForeach (stream);
case "with":
return ParseWith (stream);
case "while":
return ParseWhile (stream);
case "do":
return ParseDoWhile (stream);
case "use":
return ParseUse (stream);
case "return":
return ParseReturn (stream);
case "raise":
return ParseRaise (stream);
case "yield":
return ParseYield (stream);
case "try":
return ParseTryExcept (stream);
case "break":
stream.Accept (TokenClass.Keyword);
return new BreakStatement (stream.Location);
case "continue":
stream.Accept (TokenClass.Keyword);
return new ContinueStatement (stream.Location);
case "super":
stream.ErrorLog.AddError (ErrorType.ParserError, stream.Location,
"super () constructor must be called first!");
return ParseSuperCall (stream, new ClassDeclaration (stream.Location, "", null));
}
}
if (stream.Match (TokenClass.OpenBrace)) {
return ParseBlock (stream);
} else if (stream.Accept (TokenClass.SemiColon)) {
return new Statement (stream.Location);
} else if (stream.Match (TokenClass.Operator, "@")) {
return ParseFunction (stream);
} else {
AstNode node = ParseExpression (stream);
if (node == null) {
stream.MakeError ();
}
return new Expression (stream.Location, node);
}
}
private static AstNode ParseRange(TokenStream stream)
{
AstNode expr = ParseBoolOr (stream);
while (stream.Match (TokenClass.Operator)) {
switch (stream.Current.Value) {
case "...":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.ClosedRange, expr,
ParseBoolOr (stream));
continue;
case "..":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.HalfRange, expr,
ParseBoolOr (stream));
continue;
default:
break;
}
break;
}
return expr;
}
public static AstNode ParseBitshift(TokenStream stream)
{
AstNode expr = ParseAdditive (stream);
while (stream.Match (TokenClass.Operator)) {
switch (stream.Current.Value) {
case "<<":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.LeftShift, expr,
ParseAdditive (stream));
continue;
case ">>":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.RightShift, expr,
ParseAdditive (stream));
continue;
default:
break;
}
break;
}
return expr;
}
private static AstNode ParseBoolOr(TokenStream stream)
{
AstNode expr = ParseBoolAnd (stream);
while (stream.Match (TokenClass.Operator)) {
switch (stream.Current.Value) {
case "||":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.BoolOr, expr,
ParseBoolAnd (stream));
continue;
case "??":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.NullCoalescing, expr,
ParseBoolAnd (stream));
continue;
default:
break;
}
break;
}
return expr;
}
private static string ParseClassName(TokenStream stream)
{
StringBuilder ret = new StringBuilder ();
do {
string attr = stream.Expect (TokenClass.Identifier).Value;
ret.Append (attr);
if (stream.Match (TokenClass.Operator, "."))
ret.Append ('.');
} while (stream.Accept (TokenClass.Operator, "."));
return ret.ToString ();
}
public static AstNode ParseCallSubscriptAccess(TokenStream stream, AstNode lvalue)
{
if (stream.Match (TokenClass.OpenParan)) {
return ParseCallSubscriptAccess (stream, new CallExpression (stream.Location, lvalue,
ParseArgumentList (stream)));
} else if (stream.Match (TokenClass.OpenBracket)) {
return ParseCallSubscriptAccess (stream, ParseIndexer (lvalue, stream));
} else if (stream.Match (TokenClass.Operator, ".")) {
return ParseCallSubscriptAccess (stream, ParseGet (lvalue, stream));
}
return lvalue;
}
private static List<string> ParseFuncParameters(TokenStream stream,
out bool isInstanceMethod,
out bool isVariadic,
out bool hasKeywordArgs)
{
isVariadic = false;
hasKeywordArgs = false;
isInstanceMethod = false;
List<string> ret = new List<string> ();
stream.Expect (TokenClass.OpenParan);
if (stream.Accept (TokenClass.Keyword, "self")) {
isInstanceMethod = true;
if (!stream.Accept (TokenClass.Comma)) {
stream.Expect (TokenClass.CloseParan);
return ret;
}
}
while (!stream.Match (TokenClass.CloseParan)) {
if (!hasKeywordArgs && stream.Accept (TokenClass.Operator, "*")) {
if (stream.Accept (TokenClass.Operator, "*")) {
hasKeywordArgs = true;
Token ident = stream.Expect (TokenClass.Identifier);
ret.Add (ident.Value);
} else {
isVariadic = true;
Token ident = stream.Expect (TokenClass.Identifier);
ret.Add (ident.Value);
}
} else {
if (hasKeywordArgs) {
stream.ErrorLog.AddError (ErrorType.ParserError, stream.Location,
"Argument after keyword arguments!");
}
if (isVariadic) {
stream.ErrorLog.AddError (ErrorType.ParserError, stream.Location,
"Argument after params keyword!");
}
Token param = stream.Expect (TokenClass.Identifier);
ret.Add (param.Value);
}
if (!stream.Accept (TokenClass.Comma)) {
break;
}
}
stream.Expect (TokenClass.CloseParan);
return ret;
}
public static AstNode ParseEquals(TokenStream stream)
{
AstNode expr = ParseRelationalOp (stream);
while (stream.Match (TokenClass.Operator)) {
switch (stream.Current.Value) {
case "==":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Equals, expr,
ParseRelationalOp (stream));
continue;
case "!=":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.NotEquals, expr,
ParseRelationalOp (stream));
continue;
default:
break;
}
break;
}
return expr;
}
private static AstNode ParseFunction(TokenStream stream, bool prototype = false,
ClassDeclaration cdecl = null)
{
if (stream.Accept (TokenClass.Operator, "@")) {
/*
* Function decorators in the form of
* @myDecorator
* func foo () {
* }
* are merely syntatic sugar for
* func foo () {
* }
* foo = myDecorator (foo)
*/
AstNode expr = ParseExpression (stream); // Decorator expression
/* This is the original function which is to be decorated */
FunctionDeclaration idecl = ParseFunction (stream, prototype, cdecl) as FunctionDeclaration;
/* We must construct an arglist which will be passed to the decorator */
ArgumentList args = new ArgumentList (stream.Location);
args.Add (new NameExpression (stream.Location, idecl.Name));
/*
* Since two values can not be returned, we must return a single node containing both
* the function declaration and call to the decorator
*/
AstRoot nodes = new AstRoot (stream.Location);
nodes.Add (idecl);
nodes.Add (new Expression (stream.Location, new BinaryExpression (stream.Location,
BinaryOperation.Assign,
new NameExpression (stream.Location, idecl.Name),
new CallExpression (stream.Location, expr, args))));
return nodes;
}
stream.Expect (TokenClass.Keyword, "func");
bool isInstanceMethod;
bool isVariadic;
bool hasKeywordArgs;
Token ident = stream.Expect (TokenClass.Identifier);
List<string> parameters = ParseFuncParameters (stream,
out isInstanceMethod,
out isVariadic,
out hasKeywordArgs);
FunctionDeclaration decl = new FunctionDeclaration (stream.Location, ident != null ?
ident.Value : "",
isInstanceMethod,
isVariadic,
hasKeywordArgs,
parameters);
if (!prototype) {
if (stream.Accept (TokenClass.Operator, "=>")) {
decl.Add (new ReturnStatement (stream.Location, ParseExpression (stream)));
} else {
stream.Expect (TokenClass.OpenBrace);
CodeBlock scope = new CodeBlock (stream.Location);
if (stream.Match (TokenClass.Keyword, "super")) {
scope.Add (ParseSuperCall (stream, cdecl));
}
while (!stream.Match (TokenClass.CloseBrace)) {
scope.Add (ParseStatement (stream));
}
decl.Add (scope);
stream.Expect (TokenClass.CloseBrace);
}
}
return decl;
}
public static AstNode ParseRelationalOp(TokenStream stream)
{
AstNode expr = ParseBitshift (stream);
while (stream.Match (TokenClass.Operator)) {
switch (stream.Current.Value) {
case ">":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.GreaterThan, expr,
ParseBitshift (stream));
continue;
case "<":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.LessThan, expr,
ParseBitshift (stream));
continue;
case ">=":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.GreaterThanOrEqu, expr,
ParseBitshift (stream));
continue;
case "<=":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.LessThanOrEqu, expr,
ParseBitshift (stream));
continue;
case "is":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.InstanceOf, expr,
ParseBitshift (stream));
continue;
case "isnot":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.NotInstanceOf, expr,
ParseBitshift (stream));
continue;
case "as":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.DynamicCast, expr,
ParseBitshift (stream));
continue;
default:
break;
}
break;
}
return expr;
}
private static AstNode ParseHash(TokenStream stream)
{
stream.Expect (TokenClass.OpenBrace);
HashExpression ret = new HashExpression (stream.Location);
while (!stream.Match (TokenClass.CloseBrace)) {
ret.Add (ParseExpression (stream));
stream.Expect (TokenClass.Colon);
ret.Add (ParseExpression (stream));
if (!stream.Accept (TokenClass.Comma)) {
break;
}
}
stream.Expect (TokenClass.CloseBrace);
return ret;
}
public static AstNode ParseUnary(TokenStream stream)
{
if (stream.Match (TokenClass.Operator)) {
switch (stream.Current.Value) {
case "-":
stream.Accept (TokenClass.Operator);
return new UnaryExpression (stream.Location, UnaryOperation.Negate, ParseUnary (
stream));
case "~":
stream.Accept (TokenClass.Operator);
return new UnaryExpression (stream.Location, UnaryOperation.Not, ParseUnary (
stream));
case "!":
stream.Accept (TokenClass.Operator);
return new UnaryExpression (stream.Location, UnaryOperation.BoolNot, ParseUnary (
stream));
}
}
return ParseCallSubscriptAccess (stream);
}
private static AstNode ParseList(TokenStream stream)
{
stream.Expect (TokenClass.OpenBracket);
ListExpression ret = new ListExpression (stream.Location);
while (!stream.Match (TokenClass.CloseBracket)) {
AstNode expr = ParseExpression (stream);
if (stream.Accept (TokenClass.Keyword, "for")) {
string ident = stream.Expect (TokenClass.Identifier).Value;
stream.Expect (TokenClass.Keyword, "in");
AstNode iterator = ParseExpression (stream);
AstNode predicate = null;
if (stream.Accept (TokenClass.Keyword, "when")) {
predicate = ParseExpression (stream);
}
stream.Expect (TokenClass.CloseBracket);
return new ListCompExpression (expr.Location, expr, ident, iterator, predicate);
}
ret.Add (expr);
if (!stream.Accept (TokenClass.Comma)) {
break;
}
}
stream.Expect (TokenClass.CloseBracket);
return ret;
}
private static AstNode ParseArgumentList(TokenStream stream)
{
ArgumentList argList = new ArgumentList (stream.Location);
stream.Expect (TokenClass.OpenParan);
KeywordArgumentList kwargs = null;
while (!stream.Match (TokenClass.CloseParan)) {
if (stream.Accept (TokenClass.Operator, "*")) {
argList.Packed = true;
argList.Add (ParseExpression (stream));
break;
}
AstNode arg = ParseExpression (stream);
if (stream.Accept (TokenClass.Colon)) {
if (kwargs == null) {
kwargs = new KeywordArgumentList (arg.Location);
}
NameExpression ident = arg as NameExpression;
AstNode val = ParseExpression (stream);
if (ident == null) {
stream.ErrorLog.AddError (ErrorType.ParserError, arg.Location,
"Keyword must be a valid identifier");
} else {
kwargs.Add (ident.Value, val);
}
} else
argList.Add (arg);
if (!stream.Accept (TokenClass.Comma)) {
break;
}
}
if (kwargs != null) {
argList.Add (kwargs);
}
stream.Expect (TokenClass.CloseParan);
return argList;
}
private static AstNode ParsePatternOr(TokenStream stream)
{
AstNode expr = ParsePatternAnd (stream);
while (stream.Match (TokenClass.Operator, "|")) {
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Or, expr,
ParsePatternAnd (stream));
}
return expr;
}
private static AstNode ParseAssign(TokenStream stream)
{
AstNode expr = ParseTernaryIfElse (stream);
while (stream.Match (TokenClass.Operator)) {
switch (stream.Current.Value) {
case "=":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Assign,
expr, ParseTernaryIfElse (stream));
continue;
case "+=":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Assign, expr,
new BinaryExpression (stream.Location,
BinaryOperation.Add, expr,
ParseTernaryIfElse (stream)));
continue;
case "-=":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Assign, expr,
new BinaryExpression (stream.Location,
BinaryOperation.Sub,
expr,
ParseTernaryIfElse (stream)));
continue;
case "*=":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Assign, expr,
new BinaryExpression (stream.Location,
BinaryOperation.Mul,
expr,
ParseTernaryIfElse (stream)));
continue;
case "/=":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Assign, expr,
new BinaryExpression (stream.Location,
BinaryOperation.Div,
expr,
ParseTernaryIfElse (stream)));
continue;
case "%=":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Assign, expr,
new BinaryExpression (stream.Location,
BinaryOperation.Mod,
expr,
ParseTernaryIfElse (stream)));
continue;
case "^=":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Assign, expr,
new BinaryExpression (stream.Location,
BinaryOperation.Xor,
expr,
ParseTernaryIfElse (stream)));
continue;
case "&=":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Assign, expr,
new BinaryExpression (stream.Location,
BinaryOperation.And,
expr,
ParseTernaryIfElse (stream)));
continue;
case "|=":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Assign, expr,
new BinaryExpression (stream.Location,
BinaryOperation.Or,
expr,
ParseTernaryIfElse (stream)));
continue;
case "<<=":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Assign, expr,
new BinaryExpression (stream.Location,
BinaryOperation.LeftShift,
expr,
ParseTernaryIfElse (stream)));
continue;
case ">>=":
stream.Accept (TokenClass.Operator);
expr = new BinaryExpression (stream.Location, BinaryOperation.Assign, expr,
new BinaryExpression (stream.Location,
BinaryOperation.RightShift,
expr,
ParseTernaryIfElse (stream)));
continue;
default:
break;
}
break;
}
return expr;
}