public void Visit(VarDeclrAst ast)
{
if (ast.DeclarationType != null)
{
ast.DeclarationType.Visit(this);
}
ast.VariableName.Visit(this);
if (ast.VariableValue != null)
{
Console.WriteLine("Equals");
ast.VariableValue.Visit(this);
}
}
public void Visit(VarDeclrAst ast)
{
Exec(ast);
}
private void VariableDeclaration(VarDeclrAst varDeclrAst)
{
if (varDeclrAst.VariableValue == null)
{
var symbol = varDeclrAst.CurrentScope.Resolve(varDeclrAst.VariableName.Token.TokenValue);
var space = MemorySpaces.Current;
space.Define(symbol.Name, TokenType.Nil);
return;
}
var variableValue = varDeclrAst.VariableValue.ConvertedExpression ?? varDeclrAst.VariableValue;
// if the rhs of a variable is not a method, then execute it,
if (variableValue.AstType != AstTypes.MethodDeclr)
{
var value = GetValue(Exec(variableValue));
if (value != null)
{
var symbol = varDeclrAst.CurrentScope.Resolve(varDeclrAst.VariableName.Token.TokenValue);
var space = MemorySpaces.Current;
if (variableValue.IsLink)
{
space.Link(symbol.Name, variableValue.Token.TokenValue);
}
else
{
space.Define(symbol.Name, value);
}
}
}
else
{
var symbol = varDeclrAst.CurrentScope.Resolve(varDeclrAst.VariableName.Token.TokenValue);
var resolvedMethod = varDeclrAst.CurrentScope.Resolve(variableValue.Token.TokenValue) as MethodSymbol;
// make sure to create a NEW method symbol. this way each time we declare this item
// it will create a local copy and get its own memory space for closures.
// if we shared the same method symbol then all instances of the same declaration would share the memory space,
// which may not be what we want given class instances having their own spaces
var localMethodCopy = new MethodSymbol(resolvedMethod.Name, resolvedMethod.Type,
resolvedMethod.MethodDeclr);
var space = MemorySpaces.Current;
if (variableValue is LambdaDeclr)
{
localMethodCopy.Environment = space;
}
space.Define(symbol.Name, localMethodCopy);
}
}
private LambdaDeclr CreateCurriedMethod(FuncInvoke ast, MethodSymbol functionType)
{
var srcMethod = functionType.MethodDeclr;
var fixedAssignments = new List<VarDeclrAst>();
var count = 0;
foreach (var argValue in ast.Arguments)
{
var srcArg = srcMethod.Arguments[count] as VarDeclrAst;
var token = new Token(srcArg.DeclarationType.Token.TokenType, argValue.Token.TokenValue);
var declr = new VarDeclrAst(token, srcArg.Token, new Expr(argValue.Token));
// if we're creating a curry using a variable then we need to resolve the variable type
// otherwise we can make a symbol for the literal
var newArgType = argValue.Token.TokenType == TokenType.Word ?
ast.CurrentScope.Resolve(argValue).Type
: ScopeUtil.CreateSymbolType(argValue);
// create a symbol type for the target we're invoking on so we can do type checking
var targetArgType = ScopeUtil.CreateSymbolType(srcArg.DeclarationType);
if (!TokenUtil.EqualOrPromotable(newArgType, targetArgType))
{
throw new InvalidSyntax(String.Format("Cannot pass argument {0} of type {1} to partial function {2} as argument {3} of type {4}",
argValue.Token.TokenValue,
newArgType.TypeName,
srcMethod.MethodName.Token.TokenValue,
srcArg.VariableName.Token.TokenValue,
targetArgType.TypeName));
}
fixedAssignments.Add(declr);
count++;
}
var newBody = fixedAssignments.Concat(srcMethod.Body.ScopedStatements).ToList();
var curriedMethod = new LambdaDeclr(srcMethod.Arguments.Skip(ast.Arguments.Count).ToList(), new ScopeDeclr(newBody));
SetScope(curriedMethod);
return curriedMethod;
}
public void Visit(VarDeclrAst ast)
{
var isVar = ast.DeclarationType.Token.TokenType == TokenType.Infer;
if (ast.DeclarationType != null && !isVar)
{
var symbol = ScopeUtil.DefineUserSymbol(ast.DeclarationType, ast.VariableName);
symbol.IsArray = ast is ArrayDeclrAst;
DefineToScope(ast, symbol);
ast.AstSymbolType = symbol.Type;
}
if (ast.VariableValue == null && isVar)
{
var symbol = ScopeUtil.DefineUserSymbol(ast.DeclarationType, ast.VariableName);
DefineToScope(ast, symbol);
ast.AstSymbolType = symbol.Type;
}
else if (ast.VariableValue != null)
{
ast.VariableValue.Visit(this);
// if its type inferred, determine the declaration by the value's type
if (isVar)
{
// if the right hand side is a method declaration, make sure to track the source value
// this way we can reference it later to determine not only that this is a method type, but what
// is the expected return value for static type checking later
var val = ast.VariableValue.ConvertedExpression ?? ast.VariableValue;
ast.AstSymbolType = val is MethodDeclr
? new BuiltInType(ExpressionTypes.Method, val)
: val.AstSymbolType;
var symbol = ScopeUtil.DefineUserSymbol(ast.AstSymbolType, ast.VariableName);
symbol.IsArray = ast is ArrayDeclrAst;
DefineToScope(ast, symbol);
}
else if (ResolvingTypes)
{
var declaredType = ScopeUtil.CreateSymbolType(ast.DeclarationType);
var value = ast.VariableValue.ConvertedExpression ?? ast.VariableValue;
ReturnAst returnType = null;
// when we're resolving types check if the rhs is a function invoke. if it is, see
// what the return value of the src expression is so we can make sure that the
// lhs and the rhs match.
try
{
returnType =
value is FuncInvoke
? ((value as FuncInvoke).AstSymbolType) != null
? ((value as FuncInvoke).AstSymbolType.Src as MethodDeclr).ReturnAst
: null
: null;
}
catch
{
}
value = returnType != null ? returnType.ReturnExpression : value;
if (!TokenUtil.EqualOrPromotable(value.AstSymbolType.ExpressionType, declaredType.ExpressionType))
{
throw new InvalidSyntax(String.Format("Cannot assign {0} of type {1} to {2}", ast.VariableValue,
value.AstSymbolType.ExpressionType,
declaredType.ExpressionType));
}
}
}
SetScope(ast);
}
