Use a struct instead of an array to contain the array methods.

6 files changed, 93 insertions, 52 deletions

diff --git a/ChangeLog b/ChangeLog
index 5efa7213..8dd3b4af 100755
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,40 @@
+2019-01-07         Andrew J. Schorr      <aschorr@telemetry-investments.com>
+
+	Use a struct instead of an array to contain the array methods
+	for improved code clarity and flexibility.
+
+	* awk.h (array_funcs_t): Define new struct to contain the array
+	methods.
+	(NODE): Change type of array_funcs (sub.nodep.l.lp) from `afunc_t *'
+	to `const array_funcs_t *' (from a pointer to an array of function
+	methods to a pointer to a struct containing the methods).
+	(a*_ind): Remove obsolete method array index defines.
+	(a*): Redefine array methods to use struct members instead of 
+	array elements.
+	(str_array_func, cint_array_func, int_array_func): Change type
+	from array of afunc_t to 'const array_funcs_t'.
+	(register_array_func): Remove global declaration, since this function
+	is called only inside array.c.
+	* array.c (null_array_func): Change from array of methods to a struct.
+	(array_types): Now an array of pointers to array_funcs_t.
+	(AFUNC): Remove obsolete macro.
+	(register_array_func): Change scope to static, and change argument
+	to a pointer to array_funcs_t instead of a pointer to an array of
+	methods.
+	(array_init): Modify calls to register_array_func to pass the address
+	of the new array method structs.
+	(make_array): Set array_funcs to & null_array_func.
+	(null_lookup): Modify to use new array method structs.
+	(assoc_list): Update cint check to use & cint_array_func.
+	* str_array.c (str_array_func, env_array_func): Change from array of
+	methods to an array_funcs_t struct.
+	(env_clear, init_env_array): Set array_funcs to & env_array_func.
+	* int_array.c (int_array_func): Change from array of methods to an
+	array_funcs_t struct.
+	* cint_array.c (cint_array_func): Ditto.
+	(cint_lookup): When setting xn->array_funcs, must now use &.
+	(cint_dump): Compare xn->array_funcs to & int_array_func.
+
 2019-01-06         Andrew J. Schorr      <aschorr@telemetry-investments.com>
 
 	* array.c (do_delete): If the array is now empty, reset it to the
diff --git a/array.c b/array.c
index a47660c8..f2e64f6b 100644
--- a/array.c
+++ b/array.c
@@ -37,7 +37,8 @@ static char indent_char[] = "    ";
 
 static NODE **null_lookup(NODE *symbol, NODE *subs);
 static NODE **null_dump(NODE *symbol, NODE *subs);
-static afunc_t null_array_func[] = {
+static const array_funcs_t null_array_func = {
+	"null",
 	(afunc_t) 0,
 	(afunc_t) 0,
 	null_lookup,
@@ -52,23 +53,20 @@ static afunc_t null_array_func[] = {
 
 #define MAX_ATYPE 10
 
-static afunc_t *array_types[MAX_ATYPE];
+static const array_funcs_t *array_types[MAX_ATYPE];
 static int num_array_types = 0;
 
-/* array func to index mapping */
-#define AFUNC(F) (F ## _ind)
-
 /* register_array_func --- add routines to handle arrays */
 
-int
-register_array_func(afunc_t *afunc)
+static int
+register_array_func(const array_funcs_t *afunc)
 {
 	if (afunc && num_array_types < MAX_ATYPE) {
-		if (afunc != str_array_func && ! afunc[AFUNC(atypeof)])
+		if (afunc != & str_array_func && afunc->type_of == NULL)
 			return false;
 		array_types[num_array_types++] = afunc;
-		if (afunc[AFUNC(ainit)])	/* execute init routine if any */
-			(void) (*afunc[AFUNC(ainit)])(NULL, NULL);
+		if (afunc->init)	/* execute init routine if any */
+			(void) (*afunc->init)(NULL, NULL);
 		return true;
 	}
 	return false;
@@ -80,10 +78,10 @@ register_array_func(afunc_t *afunc)
 void
 array_init()
 {
-	(void) register_array_func(str_array_func);	/* the default */
+	(void) register_array_func(& str_array_func);	/* the default */
 	if (! do_mpfr) {
-		(void) register_array_func(int_array_func);
-		(void) register_array_func(cint_array_func);
+		(void) register_array_func(& int_array_func);
+		(void) register_array_func(& cint_array_func);
 	}
 }
 
@@ -97,7 +95,7 @@ make_array()
 	getnode(array);
 	memset(array, '\0', sizeof(NODE));
 	array->type = Node_var_array;
-	array->array_funcs = null_array_func;
+	array->array_funcs = & null_array_func;
 	/* vname, flags, and parent_array not set here */
 
 	return array;
@@ -110,7 +108,7 @@ void
 null_array(NODE *symbol)
 {
 	symbol->type = Node_var_array;
-	symbol->array_funcs = null_array_func;
+	symbol->array_funcs = & null_array_func;
 	symbol->buckets = NULL;
 	symbol->table_size = symbol->array_size = 0;
 	symbol->array_capacity = 0;
@@ -128,7 +126,7 @@ static NODE **
 null_lookup(NODE *symbol, NODE *subs)
 {
 	int i;
-	afunc_t *afunc = NULL;
+	const array_funcs_t *afunc = NULL;
 
 	assert(symbol->table_size == 0);
 
@@ -138,7 +136,7 @@ null_lookup(NODE *symbol, NODE *subs)
 	 */
 	for (i = num_array_types - 1; i >= 1; i--) {
 		afunc = array_types[i];
-		if (afunc[AFUNC(atypeof)](symbol, subs) != NULL)
+		if (afunc->type_of(symbol, subs) != NULL)
 			break;
 	}
 	if (i == 0 || afunc == NULL)
@@ -1298,7 +1296,7 @@ assoc_list(NODE *symbol, const char *sort_str, sort_context_t sort_ctxt)
 		cmp_func = sort_funcs[qi].comp_func;
 		assoc_kind = sort_funcs[qi].kind;
 
-		if (symbol->array_funcs != cint_array_func)
+		if (symbol->array_funcs != & cint_array_func)
 			assoc_kind &= ~(AASC|ADESC);
 
 		if (sort_ctxt != SORTED_IN || (assoc_kind & AVALUE) != 0) {
diff --git a/awk.h b/awk.h
index cb98491b..aa1fa91b 100644
--- a/awk.h
+++ b/awk.h
@@ -320,6 +320,19 @@ struct exp_instruction;
 
 typedef int (*Func_print)(FILE *, const char *, ...);
 typedef struct exp_node **(*afunc_t)(struct exp_node *, struct exp_node *);
+typedef struct {
+	const char *name;
+	afunc_t init;
+	afunc_t type_of;	/* avoid reserved word typeof */
+	afunc_t lookup;
+	afunc_t exists;
+	afunc_t clear;
+	afunc_t remove;
+	afunc_t list;
+	afunc_t copy;
+	afunc_t dump;
+	afunc_t store;
+} array_funcs_t;
 
 /*
  * NOTE - this struct is a rather kludgey -- it is packed to minimize
@@ -332,7 +345,7 @@ typedef struct exp_node {
 				struct exp_node *lptr;
 				struct exp_instruction *li;
 				long ll;
-				afunc_t *lp;
+				const array_funcs_t *lp;
 			} l;
 			union {
 				struct exp_node *rptr;
@@ -540,26 +553,16 @@ typedef struct exp_node {
 #define xarray		sub.nodep.rn
 #define parent_array	sub.nodep.x.extra
 
-#define ainit_ind	0
-#define ainit		array_funcs[ainit_ind]
-#define atypeof_ind	1
-#define atypeof		array_funcs[atypeof_ind]
-#define alookup_ind	2
-#define alookup 	array_funcs[alookup_ind]
-#define aexists_ind	3
-#define aexists 	array_funcs[aexists_ind]
-#define aclear_ind	4
-#define aclear		array_funcs[aclear_ind]
-#define aremove_ind	5
-#define aremove		array_funcs[aremove_ind]
-#define alist_ind	6
-#define alist		array_funcs[alist_ind]
-#define acopy_ind	7
-#define acopy		array_funcs[acopy_ind]
-#define adump_ind	8
-#define adump		array_funcs[adump_ind]
-#define astore_ind	9
-#define astore		array_funcs[astore_ind]
+#define ainit		array_funcs->init
+#define atypeof		array_funcs->type_of
+#define alookup 	array_funcs->lookup
+#define aexists 	array_funcs->exists
+#define aclear		array_funcs->clear
+#define aremove		array_funcs->remove
+#define alist		array_funcs->list
+#define acopy		array_funcs->copy
+#define adump		array_funcs->dump
+#define astore		array_funcs->store
 
 /* Node_array_ref: */
 #define orig_array lnode
@@ -1114,9 +1117,9 @@ extern NODE *(*format_val)(const char *, int, NODE *);
 extern int (*cmp_numbers)(const NODE *, const NODE *);
 
 /* built-in array types */
-extern afunc_t str_array_func[];
-extern afunc_t cint_array_func[];
-extern afunc_t int_array_func[];
+extern const array_funcs_t str_array_func;
+extern const array_funcs_t cint_array_func;
+extern const array_funcs_t int_array_func;
 
 /* special node used to indicate success in array routines (not NULL) */
 extern NODE *success_node;
@@ -1372,7 +1375,6 @@ extern NODE *force_array(NODE *symbol, bool canfatal);
 extern const char *make_aname(const NODE *symbol);
 extern const char *array_vname(const NODE *symbol);
 extern void array_init(void);
-extern int register_array_func(afunc_t *afunc);
 extern NODE **null_afunc(NODE *symbol, NODE *subs);
 extern void set_SUBSEP(void);
 extern NODE *concat_exp(int nargs, bool do_subsep);
diff --git a/cint_array.c b/cint_array.c
index 7db45fd2..497bd792 100644
--- a/cint_array.c
+++ b/cint_array.c
@@ -59,7 +59,8 @@ static NODE **cint_dump(NODE *symbol, NODE *ndump);
 static void cint_print(NODE *symbol);
 #endif
 
-afunc_t cint_array_func[] = {
+const array_funcs_t cint_array_func = {
+	"cint",
 	cint_array_init,
 	is_uinteger,
 	cint_lookup,
@@ -255,9 +256,9 @@ xinstall:
 		 */
 
 		if (is_integer(xn, subs))
-			xn->array_funcs = int_array_func;
+			xn->array_funcs = & int_array_func;
 		else
-			xn->array_funcs = str_array_func;
+			xn->array_funcs = & str_array_func;
 		xn->flags |= XARRAY;
 	}
 	return xn->alookup(xn, subs);
@@ -525,7 +526,7 @@ cint_dump(NODE *symbol, NODE *ndump)
 	kb += (INT32_BIT * sizeof(NODE *)) / 1024.0;	/* symbol->nodes */
 	kb += (symbol->array_capacity * sizeof(NODE *)) / 1024.0;	/* value nodes in Node_array_leaf(s) */
 	if (xn != NULL) {
-		if (xn->array_funcs == int_array_func)
+		if (xn->array_funcs == & int_array_func)
 			kb += int_kilobytes(xn);
 		else
 			kb += str_kilobytes(xn);
diff --git a/int_array.c b/int_array.c
index 9f705176..475f16fe 100644
--- a/int_array.c
+++ b/int_array.c
@@ -46,7 +46,8 @@ static inline NODE **int_find(NODE *symbol, long k, uint32_t hash1);
 static NODE **int_insert(NODE *symbol, long k, uint32_t hash1);
 static void grow_int_table(NODE *symbol);
 
-afunc_t int_array_func[] = {
+const array_funcs_t int_array_func = {
+	"int",
 	int_array_init,
 	is_integer,
 	int_lookup,
diff --git a/str_array.c b/str_array.c
index 4972a92b..2fdd1bf2 100644
--- a/str_array.c
+++ b/str_array.c
@@ -56,7 +56,8 @@ static NODE **str_list(NODE *symbol, NODE *subs);
 static NODE **str_copy(NODE *symbol, NODE *newsymb);
 static NODE **str_dump(NODE *symbol, NODE *ndump);
 
-afunc_t str_array_func[] = {
+const array_funcs_t str_array_func = {
+	"str",
 	str_array_init,
 	(afunc_t) 0,
 	str_lookup,
@@ -74,7 +75,8 @@ static NODE **env_store(NODE *symbol, NODE *subs);
 static NODE **env_clear(NODE *symbol, NODE *subs);
 
 /* special case for ENVIRON */
-afunc_t env_array_func[] = {
+const array_funcs_t env_array_func = {
+	"env",
 	str_array_init,
 	(afunc_t) 0,
 	str_lookup,
@@ -796,7 +798,7 @@ env_clear(NODE *symbol, NODE *subs)
 	environ = NULL;	/* ZAP! */
 
 	/* str_clear zaps the vtable, reset it */
-	symbol->array_funcs = env_array_func;
+	symbol->array_funcs = & env_array_func;
 
 	return val;
 }
@@ -829,5 +831,5 @@ init_env_array(NODE *env_node)
 	if (do_posix)
 		return;
 
-	env_node->array_funcs = env_array_func;
+	env_node->array_funcs = & env_array_func;
 }