public static LinkedListNode <Lexeme> TryParse(LinkedListNode <Lexeme> lexemes, out Var resultNode)
{
resultNode = null;
if (lexemes.Value.Type != LT.IDENT)
{
return(lexemes);
}
resultNode = new Var {
Token = lexemes.Value
};
var nextLexeme = lexemes.Next;
if (nextLexeme.Value.Type == LT.OP_SQBRACKET_O)
{
nextLexeme = nextLexeme.Next;
nextLexeme = BinaryExpr.TryParseExpr(nextLexeme, out var expr);
if (expr == null)
{
throw new Exception($"Opening square bracket found, but no array index at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
if (nextLexeme.Value.Type != LT.OP_SQBRACKET_C)
{
throw new Exception($"Missing closing square bracket after array index at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
resultNode = new ArrayVar {
Token = lexemes.Value, Index = expr
};
return(nextLexeme.Next);
}
return(nextLexeme);
}
public static LinkedListNode <Lexeme> TryParse(LinkedListNode <Lexeme> lexemes, out StructLitStmt resultNode)
{
resultNode = null;
if (lexemes.Value.Type != LT.IDENT)
{
return(lexemes);
}
var nextLexeme = lexemes.Next;
if (nextLexeme.Value.Type != LT.OP_COLON)
{
return(lexemes);
}
nextLexeme = nextLexeme.Next;
nextLexeme = BinaryExpr.TryParseExpr(nextLexeme, out var data);
if (data != null)
{
resultNode = new StructLitStmt {
Data = data, Token = lexemes.Value
};
return(nextLexeme);
}
return(lexemes);
}
public static LinkedListNode <Lexeme> TryParse(LinkedListNode <Lexeme> lexemes, out ReturnStmt resultNode)
{
resultNode = null;
if (lexemes.Value.Type != LT.KW_RETURN)
{
return(lexemes);
}
var nextLexeme = lexemes.Next;
nextLexeme = BinaryExpr.TryParseExpr(nextLexeme, out Expr expr);
if (nextLexeme.Value.Type != LT.OP_SC)
{
throw new Exception($"Missing semicolon after return statement at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
resultNode = new ReturnStmt
{
Value = expr,
Token = nextLexeme.Value
};
nextLexeme = nextLexeme.Next;
return(nextLexeme);
}
public static LinkedListNode <Lexeme> TryParseNoLit(LinkedListNode <Lexeme> lexemes, out Expr resultNode)
{
Expr node = null;
resultNode = null;
LinkedListNode <Lexeme> nextLexeme = lexemes;
if (lexemes.Value.Type == LT.OP_PAREN_O)
{
nextLexeme = BinaryExpr.TryParseExpr(lexemes.Next, out Expr expr);
if (expr != null)
{
node = expr;
if (nextLexeme.Value.Type != LT.OP_PAREN_C)
{
throw new Exception($"Missing closing parenthesis at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
nextLexeme = nextLexeme.Next;
}
}
if (node == null)
{
nextLexeme = FnCall.TryParse(lexemes, out FnCall fnc);
node = fnc;
}
if (node == null)
{
nextLexeme = Var.TryParse(lexemes, out Var v);
node = v;
}
if (node == null)
{
return(lexemes);
}
while (nextLexeme.Value.Type == LT.OP_PNT)
{
nextLexeme = Var.TryParse(nextLexeme.Next, out Var v);
if (v == null)
{
throw new Exception($"No trailing points allowed! At {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
node = new PointExpr {
Left = node, Right = v
};
}
resultNode = node;
return(nextLexeme);
}
public static LinkedListNode <Lexeme> TryParse(LinkedListNode <Lexeme> lexemes, out ArrayLit resultNode)
{
List <Expr> exprs = new List <Expr>();
resultNode = null;
if (lexemes.Value.Type != LT.OP_BRACE_O)
{
return(lexemes);
}
LinkedListNode <Lexeme> nextLexeme = lexemes.Next;
nextLexeme = BinaryExpr.TryParseExpr(nextLexeme, out var expr);
if (expr == null)
{
resultNode = new ArrayLit {
Data = exprs, Token = nextLexeme.Value
};
return(nextLexeme);
}
exprs.Add(expr);
while (nextLexeme.Value.Type == LT.OP_COMMA)
{
nextLexeme = nextLexeme.Next;
nextLexeme = BinaryExpr.TryParseExpr(nextLexeme, out expr);
if (expr == null)
{
break;
}
exprs.Add(expr);
}
resultNode = new ArrayLit {
Data = exprs, Token = nextLexeme.Value
};
if (nextLexeme.Value.Type == LT.OP_BRACE_C)
{
nextLexeme = nextLexeme.Next;
}
else
{
throw new ArgumentException($"Missing closing brace at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
return(nextLexeme);
}
public static LinkedListNode <Lexeme> TryParse(LinkedListNode <Lexeme> lexemes, out WhileLoop resultNode)
{
resultNode = null;
if (lexemes.Value.Type != LT.KW_IF)
{
return(lexemes);
}
var nextLexeme = lexemes.Next;
if (nextLexeme.Value.Type != LT.OP_PAREN_O)
{
throw new Exception($"Missing if condition at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
Lexeme token = nextLexeme.Value;
nextLexeme = BinaryExpr.TryParseExpr(nextLexeme, out Expr expr);
if (expr == null)
{
throw new Exception($"Cannot parse if condition at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
if (nextLexeme.Value.Type != LT.OP_PAREN_C)
{
throw new Exception($"Missing closing parenthesis for if condition at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
nextLexeme = nextLexeme.Next;
Stmt stmt;
List <Stmt> stmts = new List <Stmt>();
if (nextLexeme.Value.Type == LT.OP_BRACE_O)
{
// block body
nextLexeme = nextLexeme.Next;
nextLexeme = Stmt.TryParse(nextLexeme, out stmt);
while (stmt != null)
{
stmts.Add(stmt);
nextLexeme = Stmt.TryParse(nextLexeme, out stmt);
}
if (nextLexeme.Value.Type != LT.OP_BRACE_C)
{
throw new Exception($"Missing closing bracket for while loop body at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
nextLexeme = nextLexeme.Next;
}
else
{
// single statement body
nextLexeme = Stmt.TryParse(nextLexeme, out stmt);
if (stmt == null)
{
throw new Exception($"Missing while loop body at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
stmts.Add(stmt);
}
resultNode = new WhileLoop {
Condition = expr, Body = new BlockBody(stmts), Token = token
};
return(nextLexeme);
}
public static LinkedListNode <Lexeme> TryParse(LinkedListNode <Lexeme> lexemes, out ForLoop resultNode)
{
resultNode = null;
if (lexemes.Value.Type != LT.KW_FOR)
{
return(lexemes);
}
var nextLexeme = lexemes.Next;
if (nextLexeme.Value.Type != LT.OP_PAREN_O)
{
throw new Exception($"Missing loop header at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
nextLexeme = nextLexeme.Next;
nextLexeme = DeclStmt.TryParse(nextLexeme, out DeclStmt ds);
if (ds == null || !(ds is DeclAssignStmt init))
{
throw new Exception($"Cannot parse loop initializer at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
nextLexeme = BinaryExpr.TryParseExpr(nextLexeme, out Expr cond);
if (cond == null)
{
throw new Exception($"Cannot parse loop condition at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
if (nextLexeme.Value.Type != LT.OP_SC)
{
throw new Exception($"Missing semicolon after loop condition at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
nextLexeme = nextLexeme.Next;
nextLexeme = AssignStmt.TryParse(nextLexeme, out AssignStmt upd, false);
if (upd == null)
{
throw new Exception($"Cannot parse loop afterthought at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
if (nextLexeme.Value.Type != LT.OP_PAREN_C)
{
throw new Exception($"Missing closing parenthesis for loop header at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
nextLexeme = nextLexeme.Next;
Stmt stmt;
List <Stmt> stmts = new List <Stmt>();
if (nextLexeme.Value.Type == LT.OP_BRACE_O)
{
// block body
nextLexeme = nextLexeme.Next;
nextLexeme = Stmt.TryParse(nextLexeme, out stmt);
while (stmt != null)
{
stmts.Add(stmt);
nextLexeme = Stmt.TryParse(nextLexeme, out stmt);
}
if (nextLexeme.Value.Type != LT.OP_BRACE_C)
{
throw new Exception($"Missing closing bracket for loop body at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
nextLexeme = nextLexeme.Next;
}
else
{
// single statement body
nextLexeme = Stmt.TryParse(nextLexeme, out stmt);
if (stmt == null)
{
throw new Exception($"Missing loop body at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
stmts.Add(stmt);
}
resultNode = new ForLoop
{
Init = init,
Condition = cond,
Update = upd,
Body = new BlockBody(stmts)
};
return(nextLexeme);
}
public static LinkedListNode <Lexeme> TryParse(LinkedListNode <Lexeme> lexemes, out IfStmt resultNode)
{
resultNode = null;
if (lexemes.Value.Type != LT.KW_IF)
{
return(lexemes);
}
var nextLexeme = lexemes.Next;
if (nextLexeme.Value.Type != LT.OP_PAREN_O)
{
throw new Exception($"Missing if condition at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
nextLexeme = BinaryExpr.TryParseExpr(nextLexeme.Next, out Expr expr);
if (expr == null)
{
throw new Exception($"Cannot parse if condition at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
if (nextLexeme.Value.Type != LT.OP_PAREN_C)
{
throw new Exception($"Missing closing parenthesis for if condition at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
nextLexeme = nextLexeme.Next;
Stmt stmt;
List <Stmt> stmts = new List <Stmt>();
bool elseAllowed = true;
if (nextLexeme.Value.Type == LT.OP_BRACE_O)
{
// block body
nextLexeme = nextLexeme.Next;
nextLexeme = Stmt.TryParse(nextLexeme, out stmt);
while (stmt != null)
{
stmts.Add(stmt);
nextLexeme = Stmt.TryParse(nextLexeme, out stmt);
}
if (nextLexeme.Value.Type != LT.OP_BRACE_C)
{
throw new Exception($"Missing closing bracket for if body at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
nextLexeme = nextLexeme.Next;
}
else
{
// single statement body
nextLexeme = Stmt.TryParse(nextLexeme, out stmt);
if (stmt == null)
{
throw new Exception($"Missing if body at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
stmts.Add(stmt);
if (stmt is IfStmt)
{
elseAllowed = false;
}
}
if (elseAllowed)
{
if (nextLexeme.Value.Type == LT.KW_ELSE)
{
List <Stmt> elseStmts = new List <Stmt>();
nextLexeme = nextLexeme.Next;
if (nextLexeme.Value.Type == LT.OP_BRACE_O)
{
// block body
nextLexeme = nextLexeme.Next;
nextLexeme = Stmt.TryParse(nextLexeme, out stmt);
while (stmt != null)
{
elseStmts.Add(stmt);
nextLexeme = Stmt.TryParse(nextLexeme, out stmt);
}
if (nextLexeme.Value.Type != LT.OP_BRACE_C)
{
throw new Exception($"Missing closing bracket for else body at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
nextLexeme = nextLexeme.Next;
}
else
{
// single statement body
nextLexeme = Stmt.TryParse(nextLexeme, out stmt);
if (stmt == null)
{
throw new Exception($"Missing else body at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
}
elseStmts.Add(stmt);
}
resultNode = new IfStmt {
Condition = expr, Body = new BlockBody(stmts), ElseBody = new BlockBody(elseStmts), Token = lexemes.Value
};
return(nextLexeme);
}
}
resultNode = new IfStmt {
Condition = expr, Body = new BlockBody(stmts), ElseBody = null, Token = lexemes.Value
};
return(nextLexeme);
}