diff options
| -rw-r--r-- | hw09.scm | 31 |
1 files changed, 21 insertions, 10 deletions
@@ -51,6 +51,8 @@ "=" expression) "in" expression) lettype-expr) + + (expression ("emptylist(" type-exp ")") emptylist-expr) ; (3.1) primitive operations (primitive ("+") add-prim) @@ -65,13 +67,12 @@ (type-exp ("bool") bool-type-exp) (type-exp (identifier) tid-type-exp) (type-exp ("(" (separated-list type-exp "*") "->" type-exp ")") proc-type-exp) + (type-exp ("listof" type-exp) listof-type-exp) - ; (4.3) list stuffs (primitive ("cons") cons-prim) (primitive ("car") car-prim) (primitive ("cdr") cdr-prim) (primitive ("list") list-prim) - (primitive ("emptylist") empty-list-prim) (primitive ("null?") null-prim) )) @@ -112,7 +113,11 @@ (proc-type-exp (arg-texps result-texp) (proc-type (expand-type-expressions arg-texps tenv) - (expand-type-expression result-texp tenv) )) ))) + (expand-type-expression result-texp tenv) )) + + (listof-type-exp (type) (list-type type)) + + ))) (define expand-type-expressions (lambda (texps tenv) @@ -181,6 +186,9 @@ (type-of-lettype-expr type-name texp result-texps proc-names texpss idss bodies body tenv)) + + (emptylist-expr (type-name) (list-type type-name)) + ))) ; get list of types for list of expressions (typically operands) @@ -202,7 +210,6 @@ (car-prim () 1) (cdr-prim () 1) (list-prim () 1) - (empty-list-prim () 1) (null-prim () 1) ))) @@ -423,7 +430,9 @@ idss bodies lettype-body) (eval-expression lettype-body (extend-env-recursively proc-names idss bodies env))) - + + (emptylist-expr (type) '()) + ))) (define eval-program @@ -454,11 +463,10 @@ (zero-prim () (if (zero? (car args)) 1 0)) (cons-prim () (cons (car args) (cadr args))) - (car-prim () (car args)) - (cdr-prim () (cdr args)) + (car-prim () (caar args)) + (cdr-prim () (cdar args)) (list-prim () args) - (empty-list-prim () '()) - (null-prim () ((if (null? (args)) 1 0))) + (null-prim () (if (null? (car args)) 1 0)) ))) ; ------------------------------------------------------------ @@ -618,4 +626,7 @@ int apply-ff(ff f, int k) = (f k) % apply ff to value in let ff1 = (extend-ff 1 11 (extend-ff 2 22 (zero-ff))) in (apply-ff ff1 2)") -(type&run test-4.3b)
\ No newline at end of file +(type&run test-4.3b) + +(define repl read-eval-print) +(repl)
\ No newline at end of file |