more better

libfatstr/libfatstr.c

@@ -1,42 +1,35 @@
 #include <stdlib.h> /* free(3), malloc(3), realloc(3) */
-#include <string.h> /* strncpy(3) */
+#include <string.h> /* strncpy(3), size_t */
 #include "libfatstr.h"
 
 /* quick and dirty ASCII edition */
 
 /* Size by which to grow memory allocations. */
-#define GROW_INTERVAL 100
-
-struct FatStr *
-FatStr_initialize(struct FatStr *p){
-
-	if((p->v = malloc((sizeof *(p->v)) * GROW_INTERVAL)) == NULL)
-		return NULL; /* who knows */
-	p->a = GROW_INTERVAL;
-	p->s = 0;
-	return p;
-}
+static size_t FatStr_growinterval = 100; /* in sizeof chars */
 
 struct FatStr *
 FatStr_append(struct FatStr *p, FatStr_scalar_t c){
 	FatStr_vector_t t;
 
-	if(p->s + 1 > p->a){
-		if((t = realloc(p->v, (sizeof *(p->v)) * (p->a + GROW_INTERVAL)))
-				== NULL)
-			return NULL;
-		p->a += GROW_INTERVAL;
-	}
+	if(p == NULL || (p->s + (sizeof *(p->v)) > p->a
+			&& FatStr_grow(p, FatStr_growinterval) == NULL))
+		return NULL;
 	(p->v)[(p->s)++] = c;
+	return p;
+}
+
+struct FatStr *
+FatStr_construct(struct FatStr *p){
+
+	return FatStr_grow(FatStr_initialize(p), FatStr_growinterval);
 }
 
-/* retval will need to be freed */
 char *
 FatStr_convert(struct FatStr *p){
 	char *r;
 
 	/* allocation might be wrong */
-	return ((r = malloc(p->s * (sizeof *(p->v)))) == NULL)
+	return (p == NULL || (r = malloc(p->s * (sizeof *(p->v)))) == NULL)
 		? NULL
 		: strncpy(r, p->v, p->s)
 	;
@@ -44,10 +37,36 @@ FatStr_convert(struct FatStr *p){
 
 struct FatStr *
 FatStr_destruct(struct FatStr *p){
-	free(p->v);
+
+	if(p != NULL){
+		free(p->v);
+		FatStr_initialize(p);
+	}
 	return NULL;
 }
 
 struct FatStr *
-FatStr_trimfront(){
+FatStr_grow(struct FatStr *p, size_t units){
+	FatStr_vector_t t;
+
+	if(p == NULL || (t = realloc(p->v, p->a + units)) == NULL)
+		return NULL;
+	p->a += units;
+	p->v = t;
+	return p;
+}
+
+struct FatStr *
+FatStr_initialize(struct FatStr *p){
+
+	if(p != NULL){
+		p->a = 0;
+		p->s = 0;
+		p->v = NULL;
+	}
+	return p;
+}
+
+struct FatStr *
+FatStr_trimfront(struct FatStr *p, size_t units){
 }