i have long been trying find error, i'm doing programming language , have next code, using ragg, have syntax-object(resto ...) has bracket data, transform syntax-object datum:
(let ([i (syntax->datum #'(resto ...))]) (display "content i:") (display i) (if (eq? (string->symbol "(})")) (display "true") (display "false") ) ) and output is:
content: (}) false but if this
(for ([i (syntax->datum #'(resto ...))]) (displayln "content:") (displayln i) (if (eq? (string->symbol "}")) (display "true") (display "false") ) ) and output is:
content: } true my question: ¿why if of clause let false? ¿as can compare these 2 types , result true without for?
documentation functions:
each piece of code doing different thing, i'll show how make each 1 work. first 1 uses let assign variable whole list returned syntax->datum, , afterwards compare against list (better use equal? testing equality, it's more general):
(let ([i (syntax->datum #'(|}|))]) ; `i` contains `(})` (display "content i: ") (displayln i) (if (equal? '(|}|)) ; list single element, symbol `}` (displayln "true") (displayln "false"))) the second piece of code using for iterate on each element in list, until finds symbol }:
(for ([i (syntax->datum #'(|}|))]) ; `i` contains `}` (display "content i: ") (displayln i) (if (equal? '|}|) ; symbol `}` (displayln "true") (displayln "false"))) as side note, have careful way you're going process curly brackets {} in language, they're interpreted normal parentheses () in racket , they'll tricky handle, notice how had escape them surrounding them vertical bars.
