More Scheme readback machinery

We need these things in the next version so that the next-but-one
version can have a scheme evaluator!

Author: edwinb

support/chez/support.ss

@@ -504,7 +504,7 @@
   (if (number? obj) 1 0))
 
 (define (blodwen-is-integer obj)
-  (if (integer? obj) 1 0))
+  (if (and (number? obj) (exact? obj)) 1 0))
 
 (define (blodwen-is-float obj)
   (if (flonum? obj) 1 0))
@@ -530,6 +530,9 @@
 (define (blodwen-is-pair obj)
   (if (pair? obj) 1 0))
 
+(define (blodwen-is-box obj)
+  (if (box? obj) 1 0))
+
 (define (blodwen-make-symbol str)
   (string->symbol str))
 
@@ -541,9 +544,18 @@
 (define (blodwen-vector-length obj)
   (vector-length obj))
 
+(define (blodwen-vector-list obj)
+  (vector->list obj))
+
+(define (blodwen-unbox obj)
+  (unbox obj))
+
 (define (blodwen-apply obj arg)
   (obj arg))
 
+(define (blodwen-force obj)
+  (obj))
+
 (define (blodwen-read-symbol sym)
   (symbol->string sym))
 

support/racket/support.rkt

@@ -471,3 +471,84 @@
 (define (blodwen-register-object obj proc)
    (register-finalizer obj (lambda (ptr) ((proc ptr) 'erased)))
    obj)
+
+;; For creating and reading back scheme objects
+
+(define ns (make-base-namespace))
+
+; read a scheme string and evaluate it, returning 'Just result' on success
+; TODO: catch exception!
+(define (blodwen-eval-scheme str)
+  (box (eval (read (open-input-string str)) ns))) ; box == Just
+
+(define (blodwen-eval-okay obj)
+  (if (null? obj)
+      0
+      1))
+
+(define (blodwen-get-eval-result obj)
+  (unbox obj))
+
+(define (blodwen-debug-scheme obj)
+  (display obj) (newline))
+
+(define (blodwen-is-number obj)
+  (if (number? obj) 1 0))
+
+(define (blodwen-is-integer obj)
+  (if (and (number? obj) (exact? obj)) 1 0))
+
+(define (blodwen-is-float obj)
+  (if (flonum? obj) 1 0))
+
+(define (blodwen-is-char obj)
+  (if (char? obj) 1 0))
+
+(define (blodwen-is-string obj)
+  (if (string? obj) 1 0))
+
+(define (blodwen-is-procedure obj)
+  (if (procedure? obj) 1 0))
+
+(define (blodwen-is-symbol obj)
+  (if (symbol? obj) 1 0))
+
+(define (blodwen-is-vector obj)
+  (if (vector? obj) 1 0))
+
+(define (blodwen-is-nil obj)
+  (if (null? obj) 1 0))
+
+(define (blodwen-is-pair obj)
+  (if (pair? obj) 1 0))
+
+(define (blodwen-is-box obj)
+  (if (box? obj) 1 0))
+
+(define (blodwen-make-symbol str)
+  (string->symbol str))
+
+; The below rely on checking that the objects are the right type first.
+
+(define (blodwen-vector-ref obj i)
+  (vector-ref obj i))
+
+(define (blodwen-vector-length obj)
+  (vector-length obj))
+
+(define (blodwen-vector-list obj)
+  (vector->list obj))
+
+(define (blodwen-unbox obj)
+  (unbox obj))
+
+(define (blodwen-apply obj arg)
+  (obj arg))
+
+(define (blodwen-force obj)
+  (obj))
+
+(define (blodwen-read-symbol sym)
+  (symbol->string sym))
+
+(define (blodwen-id x) x)