// Parse a single statement
ast.Statement ParseSingleStatement()
{
var bmk = t.GetBookmark();
// Special handling for labels
if (t.token == Token.identifier)
{
string label = t.identifier;
t.Next();
if (t.SkipOptional(Token.colon))
{
return new ast.StatementLabel(bmk, label);
}
t.Rewind(bmk);
}
switch (t.token)
{
case Token.semicolon:
{
t.Compiler.RecordWarning(t.GetBookmark(), "unnecessary semicolon");
t.Next();
return null;
}
case Token.openBrace:
{
t.Next();
var stmt = new ast.StatementBlock(t.GetBookmark());
while (!t.SkipOptional(Token.closeBrace))
{
stmt.AddStatement(ParseSingleStatement());
}
return stmt;
}
case Token.kw_debugger:
{
t.Next();
t.SkipRequired(Token.semicolon);
return new ast.StatementDebugger(bmk, Token.kw_debugger);
}
case Token.kw_return:
{
t.Next();
if (t.SkipOptional(Token.semicolon))
{
return new ast.StatementReturnThrow(bmk, Token.kw_return);
}
else
{
var temp=new ast.StatementReturnThrow(bmk, Token.kw_return, ParseCompositeExpression(0));
t.SkipRequired(Token.semicolon);
return temp;
}
}
case Token.kw_throw:
{
t.Next();
var temp = new ast.StatementReturnThrow(bmk, Token.kw_throw, ParseCompositeExpression(0));
t.SkipRequired(Token.semicolon);
return temp;
}
case Token.kw_fallthrough:
{
// Fake statement - comment // fall through
Token op = t.token;
t.Next();
return new ast.StatementBreakContinue(bmk, op, null);
}
case Token.kw_break:
case Token.kw_continue:
{
// Statement
Token op = t.token;
t.Next();
// Optional label
if (!t.SkipOptional(Token.semicolon))
{
t.Require(Token.identifier);
var temp = new ast.StatementBreakContinue(bmk, op, t.identifier);
t.Next();
t.Require(Token.semicolon);
return temp;
}
// No label
return new ast.StatementBreakContinue(bmk, op, null);
}
case Token.kw_if:
{
t.Next();
// Condition
t.SkipRequired(Token.openRound);
var stmt=new ast.StatementIfElse(bmk, ParseCompositeExpression(0));
t.SkipRequired(Token.closeRound);
// True code block
stmt.TrueStatement=ParseStatement();
// Optional else block
if (t.SkipOptional(Token.kw_else))
{
stmt.FalseStatement=ParseStatement();
}
return stmt;
}
case Token.kw_switch:
{
t.Next();
// Value
t.SkipRequired(Token.openRound);
var stmt = new ast.StatementSwitch(bmk, ParseCompositeExpression(0));
t.SkipRequired(Token.closeRound);
// Opening brace
t.SkipRequired(Token.openBrace);
// Parse all cases
ast.StatementSwitch.Case currentCase = null;
while (t.token!=Token.closeBrace)
{
// new case?
if (t.SkipOptional(Token.kw_case))
{
currentCase = stmt.AddCase(ParseCompositeExpression(0));
t.SkipRequired(Token.colon);
continue;
}
// default case?
if (t.SkipOptional(Token.kw_default))
{
currentCase = stmt.AddCase(null);
t.SkipRequired(Token.colon);
continue;
}
// Must have a case
if (currentCase == null)
{
throw new CompileError("Unexpected code in switch statement before 'case' or 'default'", t);
}
currentCase.AddCode(ParseSingleStatement());
}
// Done
t.SkipRequired(Token.closeBrace);
return stmt;
}
case Token.kw_for:
{
// Statement
t.Next();
t.SkipRequired(Token.openRound);
ast.Statement init = null;
if (t.token != Token.semicolon)
{
// Initializers
init = ParseVarDeclStatement(ParseContext.DisableInOperator | ParseContext.AllowCompositeExpressions);
// Foreach iterator
if (t.SkipOptional(Token.kw_in))
{
var stmtForEach = new ast.StatementForIn(bmk);
var decl = init as ast.StatementVariableDeclaration;
if (decl != null)
{
if (decl.HasInitialValue())
{
throw new CompileError("Syntax error - unexpected initializer in for-in statement", t);
}
if (decl.Variables.Count > 1)
{
throw new CompileError("Syntax error - unexpected multiple iterator variables in for-in statement", t);
}
stmtForEach.VariableDeclaration = init;
}
else
{
var exprstmtForEach = init as ast.StatementExpression;
if (exprstmtForEach == null)
{
throw new CompileError("Syntax error - invalid iterator variable declarations in for loop", t);
}
if ((exprstmtForEach.Expression.RootNode as ast.ExprNodeIdentifier) == null &&
(exprstmtForEach.Expression.RootNode as ast.ExprNodeIndexer) == null)
{
throw new CompileError("Syntax error - invalid iterator variable declarations in for loop", t);
}
stmtForEach.Iterator = exprstmtForEach.Expression;
}
// Collection
stmtForEach.Collection = ParseCompositeExpression(0);
t.SkipRequired(Token.closeRound);
// Parse content
stmtForEach.Code = ParseStatement();
return stmtForEach;
}
}
// Create the statement, store the initialization expression(s)
var stmt = new ast.StatementFor(bmk);
stmt.Initialize = init;
t.SkipRequired(Token.semicolon);
// Condition
if (t.token!=Token.semicolon)
stmt.Condition = ParseCompositeExpression(0);
t.SkipRequired(Token.semicolon);
// Iterator
if (t.token!=Token.closeRound)
stmt.Increment = ParseCompositeExpression(ParseContext.AllowCompositeExpressions);
t.SkipRequired(Token.closeRound);
// Parse code block
stmt.Code = ParseStatement();
return stmt;
}
case Token.kw_do:
{
var stmt = new ast.StatementDoWhile(bmk);
t.Next();
stmt.Code = ParseStatement();
t.SkipRequired(Token.kw_while);
t.SkipRequired(Token.openRound);
stmt.Condition = ParseCompositeExpression(ParseContext.AllowCompositeExpressions);
t.SkipRequired(Token.closeRound);
t.SkipRequired(Token.semicolon);
return stmt;
}
case Token.kw_while:
{
var stmt = new ast.StatementWhile(bmk);
t.Next();
t.SkipRequired(Token.openRound);
stmt.Condition = ParseCompositeExpression(ParseContext.AllowCompositeExpressions);
t.SkipRequired(Token.closeRound);
stmt.Code = ParseStatement();
return stmt;
}
case Token.kw_with:
{
var stmt = new ast.StatementWith(bmk);
t.Next();
t.SkipRequired(Token.openRound);
stmt.Expression = ParseCompositeExpression(0);
t.SkipRequired(Token.closeRound);
stmt.Code = ParseStatement();
return stmt;
}
case Token.kw_try:
{
t.Next();
// Create the statement
var stmt = new ast.StatementTryCatchFinally(bmk);
// The code
t.Require(Token.openBrace);
stmt.Code = ParseStatementBlock(TriState.Yes);
// Catch clauses
bmk = t.GetBookmark();
while (t.SkipOptional(Token.kw_catch))
{
var cc=new ast.CatchClause(bmk);
// Catch expression
t.SkipRequired(Token.openRound);
// Exception variable name
t.Require(Token.identifier);
cc.ExceptionVariable=t.identifier;
t.Next();
// Optional 'if <condition>' (firefox extension)
if (t.token==Token.kw_if)
{
t.Next();
cc.Condition=ParseCompositeExpression(0);
}
// End of expression
t.SkipRequired(Token.closeRound);
// Code block
t.Require(Token.openBrace);
cc.Code=ParseStatementBlock(TriState.Yes);
stmt.CatchClauses.Add(cc);
bmk = t.GetBookmark();
}
// Finally
if (t.SkipOptional(Token.kw_finally))
{
t.Require(Token.openBrace);
stmt.FinallyClause = ParseStatementBlock(TriState.Yes);
}
return stmt;
}
case Token.kw_function:
{
// Function declaration
t.Next();
t.Require(Token.identifier);
var stmt = new ast.StatementExpression(bmk, new ast.Expression(ParseFunction()));
t.SkipOptional(Token.semicolon);
return stmt;
}
case Token.directive_comment:
{
var stmt = new ast.StatementComment(bmk, t.RawToken.Substring(0,2) + t.RawToken.Substring(3));
t.Next();
return stmt;
}
case Token.directive_private:
case Token.directive_public:
{
var stmt = new ast.StatementAccessibility(bmk);
foreach (var symbol in t.identifier.Split(','))
{
var spec = new AccessibilitySpec();
if (!spec.Parse(t.token==Token.directive_private ? Accessibility.Private : Accessibility.Public,
symbol))
{
throw new CompileError(string.Format("Invalid private member declaration - `{0}`", symbol), t);
}
stmt.Specs.Add(spec);
}
t.Next();
return stmt;
}
default:
{
// Must be a variable declaration or an expression
var stmt = ParseVarDeclStatement(0);
t.SkipRequired(Token.semicolon);
return stmt;
}
}
}
// Parse a single statement
ast.Statement ParseSingleStatement()
{
var bmk = t.GetBookmark();
// Special handling for labels
if (t.token == Token.identifier)
{
string label = t.identifier;
t.Next();
if (t.SkipOptional(Token.colon))
{
return(new ast.StatementLabel(bmk, label));
}
t.Rewind(bmk);
}
switch (t.token)
{
case Token.semicolon:
{
t.Compiler.RecordWarning(t.GetBookmark(), "unnecessary semicolon");
t.Next();
return(null);
}
case Token.openBrace:
{
t.Next();
var stmt = new ast.StatementBlock(t.GetBookmark());
while (!t.SkipOptional(Token.closeBrace))
{
stmt.AddStatement(ParseSingleStatement());
}
return(stmt);
}
case Token.kw_debugger:
{
t.Next();
t.SkipRequired(Token.semicolon);
return(new ast.StatementDebugger(bmk, Token.kw_debugger));
}
case Token.kw_return:
{
t.Next();
if (t.SkipOptional(Token.semicolon))
{
return(new ast.StatementReturnThrow(bmk, Token.kw_return));
}
else
{
var temp = new ast.StatementReturnThrow(bmk, Token.kw_return, ParseCompositeExpression(0));
t.SkipRequired(Token.semicolon);
return(temp);
}
}
case Token.kw_throw:
{
t.Next();
var temp = new ast.StatementReturnThrow(bmk, Token.kw_throw, ParseCompositeExpression(0));
t.SkipRequired(Token.semicolon);
return(temp);
}
case Token.kw_fallthrough:
{
// Fake statement - comment // fall through
Token op = t.token;
t.Next();
return(new ast.StatementBreakContinue(bmk, op, null));
}
case Token.kw_break:
case Token.kw_continue:
{
// Statement
Token op = t.token;
t.Next();
// Optional label
if (!t.SkipOptional(Token.semicolon))
{
t.Require(Token.identifier);
var temp = new ast.StatementBreakContinue(bmk, op, t.identifier);
t.Next();
t.Require(Token.semicolon);
return(temp);
}
// No label
return(new ast.StatementBreakContinue(bmk, op, null));
}
case Token.kw_if:
{
t.Next();
// Condition
t.SkipRequired(Token.openRound);
var stmt = new ast.StatementIfElse(bmk, ParseCompositeExpression(0));
t.SkipRequired(Token.closeRound);
// True code block
stmt.TrueStatement = ParseStatement();
// Optional else block
if (t.SkipOptional(Token.kw_else))
{
stmt.FalseStatement = ParseStatement();
}
return(stmt);
}
case Token.kw_switch:
{
t.Next();
// Value
t.SkipRequired(Token.openRound);
var stmt = new ast.StatementSwitch(bmk, ParseCompositeExpression(0));
t.SkipRequired(Token.closeRound);
// Opening brace
t.SkipRequired(Token.openBrace);
// Parse all cases
ast.StatementSwitch.Case currentCase = null;
while (t.token != Token.closeBrace)
{
// new case?
if (t.SkipOptional(Token.kw_case))
{
currentCase = stmt.AddCase(ParseCompositeExpression(0));
t.SkipRequired(Token.colon);
continue;
}
// default case?
if (t.SkipOptional(Token.kw_default))
{
currentCase = stmt.AddCase(null);
t.SkipRequired(Token.colon);
continue;
}
// Must have a case
if (currentCase == null)
{
throw new CompileError("Unexpected code in switch statement before 'case' or 'default'", t);
}
currentCase.AddCode(ParseSingleStatement());
}
// Done
t.SkipRequired(Token.closeBrace);
return(stmt);
}
case Token.kw_for:
{
// Statement
t.Next();
t.SkipRequired(Token.openRound);
ast.Statement init = null;
if (t.token != Token.semicolon)
{
// Initializers
init = ParseVarDeclStatement(ParseContext.DisableInOperator | ParseContext.AllowCompositeExpressions);
// Foreach iterator
if (t.SkipOptional(Token.kw_in))
{
var stmtForEach = new ast.StatementForIn(bmk);
var decl = init as ast.StatementVariableDeclaration;
if (decl != null)
{
if (decl.HasInitialValue())
{
throw new CompileError("Syntax error - unexpected initializer in for-in statement", t);
}
if (decl.Variables.Count > 1)
{
throw new CompileError("Syntax error - unexpected multiple iterator variables in for-in statement", t);
}
stmtForEach.VariableDeclaration = init;
}
else
{
var exprstmtForEach = init as ast.StatementExpression;
if (exprstmtForEach == null)
{
throw new CompileError("Syntax error - invalid iterator variable declarations in for loop", t);
}
if ((exprstmtForEach.Expression.RootNode as ast.ExprNodeIdentifier) == null &&
(exprstmtForEach.Expression.RootNode as ast.ExprNodeIndexer) == null)
{
throw new CompileError("Syntax error - invalid iterator variable declarations in for loop", t);
}
stmtForEach.Iterator = exprstmtForEach.Expression;
}
// Collection
stmtForEach.Collection = ParseCompositeExpression(0);
t.SkipRequired(Token.closeRound);
// Parse content
stmtForEach.Code = ParseStatement();
return(stmtForEach);
}
}
// Create the statement, store the initialization expression(s)
var stmt = new ast.StatementFor(bmk);
stmt.Initialize = init;
t.SkipRequired(Token.semicolon);
// Condition
if (t.token != Token.semicolon)
{
stmt.Condition = ParseCompositeExpression(0);
}
t.SkipRequired(Token.semicolon);
// Iterator
if (t.token != Token.closeRound)
{
stmt.Increment = ParseCompositeExpression(ParseContext.AllowCompositeExpressions);
}
t.SkipRequired(Token.closeRound);
// Parse code block
stmt.Code = ParseStatement();
return(stmt);
}
case Token.kw_do:
{
var stmt = new ast.StatementDoWhile(bmk);
t.Next();
stmt.Code = ParseStatement();
t.SkipRequired(Token.kw_while);
t.SkipRequired(Token.openRound);
stmt.Condition = ParseCompositeExpression(ParseContext.AllowCompositeExpressions);
t.SkipRequired(Token.closeRound);
t.SkipRequired(Token.semicolon);
return(stmt);
}
case Token.kw_while:
{
var stmt = new ast.StatementWhile(bmk);
t.Next();
t.SkipRequired(Token.openRound);
stmt.Condition = ParseCompositeExpression(ParseContext.AllowCompositeExpressions);
t.SkipRequired(Token.closeRound);
stmt.Code = ParseStatement();
return(stmt);
}
case Token.kw_with:
{
var stmt = new ast.StatementWith(bmk);
t.Next();
t.SkipRequired(Token.openRound);
stmt.Expression = ParseCompositeExpression(0);
t.SkipRequired(Token.closeRound);
stmt.Code = ParseStatement();
return(stmt);
}
case Token.kw_try:
{
t.Next();
// Create the statement
var stmt = new ast.StatementTryCatchFinally(bmk);
// The code
t.Require(Token.openBrace);
stmt.Code = ParseStatementBlock(TriState.Yes);
// Catch clauses
bmk = t.GetBookmark();
while (t.SkipOptional(Token.kw_catch))
{
var cc = new ast.CatchClause(bmk);
// Catch expression
t.SkipRequired(Token.openRound);
// Exception variable name
t.Require(Token.identifier);
cc.ExceptionVariable = t.identifier;
t.Next();
// Optional 'if <condition>' (firefox extension)
if (t.token == Token.kw_if)
{
t.Next();
cc.Condition = ParseCompositeExpression(0);
}
// End of expression
t.SkipRequired(Token.closeRound);
// Code block
t.Require(Token.openBrace);
cc.Code = ParseStatementBlock(TriState.Yes);
stmt.CatchClauses.Add(cc);
bmk = t.GetBookmark();
}
// Finally
if (t.SkipOptional(Token.kw_finally))
{
t.Require(Token.openBrace);
stmt.FinallyClause = ParseStatementBlock(TriState.Yes);
}
return(stmt);
}
case Token.kw_function:
{
// Function declaration
t.Next();
t.Require(Token.identifier);
var stmt = new ast.StatementExpression(bmk, new ast.Expression(ParseFunction()));
t.SkipOptional(Token.semicolon);
return(stmt);
}
case Token.directive_comment:
{
var stmt = new ast.StatementComment(bmk, t.RawToken.Substring(0, 2) + t.RawToken.Substring(3));
t.Next();
return(stmt);
}
case Token.directive_private:
case Token.directive_public:
{
var stmt = new ast.StatementAccessibility(bmk);
foreach (var symbol in t.identifier.Split(','))
{
var spec = new AccessibilitySpec();
if (!spec.Parse(t.token == Token.directive_private ? Accessibility.Private : Accessibility.Public,
symbol))
{
throw new CompileError(string.Format("Invalid private member declaration - `{0}`", symbol), t);
}
stmt.Specs.Add(spec);
}
t.Next();
return(stmt);
}
default:
{
// Must be a variable declaration or an expression
var stmt = ParseVarDeclStatement(0);
t.SkipRequired(Token.semicolon);
return(stmt);
}
}
}