private Ast.IExpression ParseHashLiteral()
{
var hash = new Ast.HashLiteral {
Token = _curToken,
Pairs = new Dictionary <Ast.IExpression, Ast.IExpression>()
};
while (!PeekTokenIs(TokenType.Rbrace))
{
NextToken();
var key = ParseExpression(Precedence.Lowest);
if (!ExpectPeek(TokenType.Colon))
{
return(null);
}
NextToken();
var value = ParseExpression(Precedence.Lowest);
hash.Pairs[key] = value;
if (!PeekTokenIs(TokenType.Rbrace) && !ExpectPeek(TokenType.Comma))
{
return(null);
}
}
if (!ExpectPeek(TokenType.Rbrace))
{
return(null);
}
return(hash);
}
private static IObject EvalHashLiteral(Ast.HashLiteral node, Environment env)
{
var pairs = new Dictionary <HashKey, HashPair>();
foreach (var pair in node.Pairs)
{
var key = Eval(pair.Key, env);
if (IsError(key))
{
return(key);
}
if (!(key is IHashable hashKey))
{
return new Error {
Message = $"unusable as hash key: {key.getType()}"
}
}
;
var value = Eval(pair.Value, env);
if (IsError(value))
{
return(value);
}
var hashed = hashKey.HashKey();
pairs[hashed] = new HashPair {
Key = key, Value = value
};
}
return(new Hash {
Pairs = pairs
});
}
}
