protected void ExecuteVarDeclStmt(AstVarDeclStmt stmt)
{
if (HadErrorOrReturn())
{
return;
}
object value = null;
if (stmt.m_initExpr != null)
{
value = EvaluateExpr(stmt.m_initExpr);
}
bool success = m_environment.Define(stmt.m_identifier.m_identifier, value);
if (!success)
{
// TODO: Print the line that the first definition was on? To do that we would have to store
// line numbers in the environment. Also, it wouldn't really make sense for repl mode so we would
// have to have a way to check if we are in repl mode.
m_runtimeError = true;
Lox.Error(stmt.m_startLine, "Redefinition of identifier " + stmt.m_identifier.m_identifier);
}
}
protected void ResolveVarDeclStmt(AstVarDeclStmt stmt)
{
var scope = Scope();
if (scope == null)
{
return; // TODO: Better global handling
}
if (scope.ContainsKey(stmt.m_identifier.m_identifier))
{
m_error = true;
Lox.Error(stmt.m_startLine, "Redefinition of identifier \"" + stmt.m_identifier.m_identifier + "\" in same scope");
return;
}
// Declared but not yet initialized
scope[stmt.m_identifier.m_identifier] = false;
if (stmt.m_initExpr != null)
{
ResolveExpr(stmt.m_initExpr);
}
// Declared and initialized
scope[stmt.m_identifier.m_identifier] = true;
}
public AstForStmt(int startLine, AstVarDeclStmt pre, AstExpr condition, AstExpr post, AstStmt body)
: base(STMTK.For, startLine)
{
m_preDecl = pre;
m_condition = condition;
m_post = post;
m_body = body;
}
protected AstStmt ParseForStmt()
{
PushLoop();
try
{
Token forToken = Previous();
Debug.Assert(forToken.m_tokenk == TOKENK.For);
Token openParen;
Token closeParen;
AstVarDeclStmt preDecl = null;
AstExpr preExpr = null;
AstExpr condition = null;
AstExpr post = null;
Token semicolon;
if ((openParen = TryMatch(TOKENK.OpenParen)) == null)
{
return(ErrorStmt(forToken.m_line, "Expected '(' after \"for\""));
}
if ((semicolon = TryMatch(TOKENK.Semicolon)) == null)
{
Token varToken;
if ((varToken = TryMatch(TOKENK.Var)) != null)
{
AstStmt stmt = ParseVarDeclStmt();
if (stmt == null)
{
return(EmptyErrorStmt());
}
Debug.Assert(stmt.m_stmtk == STMTK.VarDecl);
preDecl = (AstVarDeclStmt)stmt;
}
else
{
AstStmt stmt = ParseExprStmt();
if (stmt == null)
{
return(EmptyErrorStmt());
}
Debug.Assert(stmt.m_stmtk == STMTK.Expr);
preExpr = ((AstExprStmt)stmt).m_expr;
}
}
if ((semicolon = TryMatch(TOKENK.Semicolon)) == null)
{
AstStmt stmt = ParseExprStmt();
if (stmt == null)
{
return(EmptyErrorStmt());
}
Debug.Assert(stmt.m_stmtk == STMTK.Expr);
condition = ((AstExprStmt)stmt).m_expr;
}
if ((closeParen = TryMatch(TOKENK.CloseParen)) == null)
{
post = ParseExpr();
if (post == null)
{
return(EmptyErrorStmt());
}
if ((closeParen = TryMatch(TOKENK.CloseParen)) == null)
{
return(ErrorStmt(forToken.m_line, "Expected ')' at end of \"for\""));
}
}
AstStmt body = ParseStmt();
if (body == null)
{
return(EmptyErrorStmt());
}
if (preDecl != null)
{
return(new AstForStmt(forToken.m_line, preDecl, condition, post, body));
}
else
{
return(new AstForStmt(forToken.m_line, preExpr, condition, post, body));
}
}
finally
{
PopLoop();
}
}
