Writing strings to a file.

insomniac_as

@@ -48,7 +48,8 @@ idx! ( index obj vector -- ) Takes an index, object, and vector/record/byte vect
 vec-len ( vector -- size)    Takes a vector as an argument and returns
                                 the vectors length.
 
-str->slice (string -- slice) Convert a string into bytevector slice. 
+str->slice ( string -- slice ) Convert a string into bytevector slice. 
+u8->str ( u8 -- string ) Convert a bytevector into a string.
 
 slice ( start end vector -- slice ) Given a vector or bytevector, return a vector of the same
                                     type that is backed by the same data store as the original.

lib/ports/core.scm

@@ -110,8 +110,8 @@
 (define write-bytevector
     (writer-factory bytevector-length slice))
 
-;(define write-string
-;    (writer-factory string-length (lambda (str) str)))
+(define write-string
+    (writer-factory string-length substring))
 
 (define (read-bytevector k . args)
     (define port

lib/ports/textual.scm

@@ -12,7 +12,7 @@
     (begin
         (define (text-write str num fd)
             (write-bytevector
-                (string->utf8 string 0 num)))
+                (slice (string->u8 str) 0 num) fd))
 
         (define (text-read num fd) 
            "")

lib/strings.scm

@@ -2,15 +2,27 @@
 ;;; Some basic string functions
 ;;;
 
-;; Directly convert a string into a bytevector
+;; Directly convert a string into a bytevector.
 (define (string->u8 str)
     (asm (str) str->slice))
 
+;; Directly convert a byte vector into a string.
+(define (u8->string u8)
+    (asm (u8) u8->str))
+
+;; Determine the length of a string.
+(define (string-length str)
+    (bytevector-length (string->u8 str)))
+
+;; Slice a string.
+(define (substring str start end)
+    (u8->string
+        (slice (string->u8 str) start end)))
 
 ;; Convert a String into a utf8 
-(define (utf8->string bytevector . args)
-    "")
+;;(define (utf8->string bytevector . args)
+;;    "")
 
-(define (string->utf8 string . args)
-    (bytevector 0))
+;;(define (string->utf8 string . args)
+;;    (bytevector 0))
 

src/include/ops.h

@@ -32,6 +32,7 @@ typedef enum op {
     OP_VECTOR_LENGTH,    /* return the length of a vector */
     OP_SLICE,            /* returns a slice of a vector */
     OP_STRING_SLICE,     /* returns a slice of a string */
+    OP_BYTE_VECTOR_STRING, /* returns a string from a bytevector */
 
     /* jump operations Jumps are relative */
     OP_CALL,         /* call the given target and leave return on stack */

src/libinsomniac_asm/lexer.l

@@ -60,6 +60,7 @@ CHAR_VAL  (newline|space|eof|[^{WS}])
 "vec-len"               { return OP_VECTOR_LENGTH; }
 "slice"                 { return OP_SLICE; }
 "str->slice"            { return OP_STRING_SLICE; }
+"u8->str"               { return OP_BYTE_VECTOR_STRING; }
 
 "out"                   { return OP_OUTPUT; }
 "read"                  { return OP_FD_READ; }

src/libinsomniac_vm/libinsomniac_vm_instructions/vm_instructions_internal.h

@@ -35,6 +35,7 @@ void op_index_ref(vm_internal_type *vm);
 void op_vector_length(vm_internal_type *vm);
 void op_slice(vm_internal_type *vm);
 void op_string_slice(vm_internal_type *vm);
+void op_byte_vector_string(vm_internal_type *vm);
 
 /* list operations */
 void op_cons(vm_internal_type *vm);

src/libinsomniac_vm/libinsomniac_vm_instructions/vm_ops.c

@@ -53,6 +53,7 @@ void setup_instructions(vm_internal_type *vm) {
     vm->ops[OP_VECTOR_LENGTH] = &op_vector_length;
     vm->ops[OP_SLICE] = &op_slice;
     vm->ops[OP_STRING_SLICE] = &op_string_slice;
+    vm->ops[OP_BYTE_VECTOR_STRING] = &op_byte_vector_string;
 
     vm->ops[OP_CONS] = &op_cons;
     vm->ops[OP_CAR] = &op_car;

src/libinsomniac_vm/libinsomniac_vm_instructions/vm_vector.c

@@ -229,3 +229,20 @@ void op_string_slice(vm_internal_type *vm) {
     vm_push(vm, vm->reg2);
 }
 
+/* Return a string from a bytevector. */
+void op_byte_vector_string(vm_internal_type *vm) {
+    object_type *vector = 0;
+
+    vm->reg1 = vector = vm_pop(vm);
+
+    if (vector->type != BYTE_VECTOR) {
+        throw(vm, "u8->str requires a bytevector argument.", 1, vector);
+        return;
+    }
+
+    vm->reg2 = vm_make_string(
+        vm, (char *)vector->value.byte_vector.vector, vector->value.byte_vector.length);
+
+    vm_push(vm, vm->reg2);
+
+}