From: NeilBrown <neil@brown.name>
Date: Wed, 1 May 2019 09:01:48 +0000 (+1000)
Subject: oceani: add array type.
X-Git-Tag: JamisonCreek-3~28
X-Git-Url: https://ocean-lang.org/code/?p=ocean;a=commitdiff_plain;h=c54deb38566c666b8b84dc9d2898a320bf40a136

oceani: add array type.

I can now declare arrays and access or assign
members there-of.

Signed-off-by: NeilBrown <neil@brown.name>
---

diff --git a/csrc/oceani.mdc b/csrc/oceani.mdc
index 9ab456a..27c0c32 100644
--- a/csrc/oceani.mdc
+++ b/csrc/oceani.mdc
@@ -1758,6 +1758,7 @@ link to find the primary instance.
 		}
 		cast(var, $0)->var = v;
 	} }$
+	## variable grammar
 
 	$*type
 	Type -> IDENTIFIER ${
@@ -1769,6 +1770,7 @@ link to find the primary instance.
 			$0 = Tnone;
 		}
 	}$
+	## type grammar
 
 ###### print exec cases
 	case Xvar:
@@ -3199,6 +3201,217 @@ defined.
 		break;
 	}
 
+## Complex types
+
+Now that we have the shape of the interpreter in place we can add some
+complex types and connected them in to the data structures and the
+different phases of parse, analyse, print, interpret.
+
+For now, just arrays.
+
+### Arrays
+
+Arrays can be declared by giving a size and a type, as `[size]type' so
+`freq:[26]number` declares `freq` to be an array of 26 numbers.  The
+size can be an arbitrary expression which is evaluated when the name
+comes into scope.
+
+Arrays cannot be assigned.  When pointers are introduced we will also
+introduce array slices which can refer to part or all of an array -
+the assignment syntax will create a slice.  For now, an array can only
+ever be referenced by the name it is declared with.  It is likely that
+a "`copy`" primitive will eventually be define which can be used to
+make a copy of an array with controllable depth.
+
+###### type union fields
+
+	struct {
+		int size;
+		struct variable *vsize;
+		struct type *member;
+	} array;
+
+###### value union fields
+	struct {
+		struct value *elmnts;
+	} array;
+
+###### value functions
+
+	static struct value array_prepare(struct type *type)
+	{
+		struct value ret;
+
+		ret.type = type;
+		ret.array.elmnts = NULL;
+		return ret;
+	}
+
+	static struct value array_init(struct type *type)
+	{
+		struct value ret;
+		int i;
+
+		ret.type = type;
+		if (type->array.vsize) {
+			mpz_t q;
+			mpz_init(q);
+			mpz_tdiv_q(q, mpq_numref(type->array.vsize->val.num),
+			           mpq_denref(type->array.vsize->val.num));
+			type->array.size = mpz_get_si(q);
+			mpz_clear(q);
+		}
+		ret.array.elmnts = calloc(type->array.size,
+		                          sizeof(ret.array.elmnts[0]));
+		for (i = 0; ret.array.elmnts && i < type->array.size; i++)
+			ret.array.elmnts[i] = val_init(type->array.member);
+		return ret;
+	}
+
+	static void array_free(struct value val)
+	{
+		int i;
+
+		if (val.array.elmnts)
+			for (i = 0; i < val.type->array.size; i++)
+				free_value(val.array.elmnts[i]);
+		free(val.array.elmnts);
+	}
+
+	static int array_compat(struct type *require, struct type *have)
+	{
+		if (have->compat != require->compat)
+			return 0;
+		/* Both are arrays, so we can look at details */
+		if (!type_compat(require->array.member, have->array.member, 0))
+			return 0;
+		if (require->array.vsize == NULL && have->array.vsize == NULL)
+			return require->array.size == have->array.size;
+
+		return require->array.vsize == have->array.vsize;
+	}
+
+	static void array_print_type(struct type *type, FILE *f)
+	{
+		fputs("[", f);
+		if (type->array.vsize) {
+			struct binding *b = type->array.vsize->name;
+			fprintf(f, "%.*s]", b->name.len, b->name.txt);
+		} else
+			fprintf(f, "%d]", type->array.size);
+		type_print(type->array.member, f);
+	}
+
+	static struct type array_prototype = {
+		.prepare = array_prepare,
+		.init = array_init,
+		.print_type = array_print_type,
+		.compat = array_compat,
+		.free = array_free,
+	};
+
+###### type grammar
+
+	| [ NUMBER ] Type ${
+		$0 = calloc(1, sizeof(struct type));
+		*($0) = array_prototype;
+		$0->array.member = $<4;
+		$0->array.vsize = NULL;
+		{
+		char tail[3];
+		mpq_t num;
+		if (number_parse(num, tail, $2.txt) == 0)
+			tok_err(config2context(config), "error: unrecognised number", &$2);
+		else if (tail[0])
+			tok_err(config2context(config), "error: unsupported number suffix", &$2);
+		else {
+			$0->array.size = mpz_get_ui(mpq_numref(num));
+			if (mpz_cmp_ui(mpq_denref(num), 1) != 0) {
+				tok_err(config2context(config), "error: array size must be an integer",
+				        &$2);
+			} else if (mpz_cmp_ui(mpq_numref(num), 1UL << 30) >= 0)
+				tok_err(config2context(config), "error: array size is too large",
+				        &$2);
+		}
+		}
+	}$
+
+	| [ IDENTIFIER ] Type ${ {
+		struct variable *v = var_ref(config2context(config), $2.txt);
+
+		if (!v)
+			tok_err(config2context(config), "error: name undeclared", &$2);
+		else if (!v->constant)
+			tok_err(config2context(config), "error: array size must be a constant", &$2);
+
+		$0 = calloc(1, sizeof(struct type));
+		*($0) = array_prototype;
+		$0->array.member = $<4;
+		$0->array.size = 0;
+		$0->array.vsize = v;
+	} }$
+
+###### Binode types
+	Index,
+
+###### variable grammar
+
+	| Variable [ Expression ] ${ {
+		struct binode *b = new(binode);
+		b->op = Index;
+		b->left = $<1;
+		b->right = $<3;
+		$0 = b;
+	} }$
+
+###### print binode cases
+	case Index:
+		print_exec(b->left, -1, 0);
+		printf("[");
+		print_exec(b->right, -1, 0);
+		printf("]");
+		break;
+
+###### propagate binode cases
+	case Index:
+		/* left must be an array, right must be a number,
+		 * result is the member type of the array
+		 */
+		propagate_types(b->right, c, ok, Tnum, 0);
+		t = propagate_types(b->left, c, ok, NULL, rules & Rnoconstant);
+		if (!t || t->compat != array_compat) {
+			type_err(c, "error: %1 cannot be indexed", prog, t, 0, NULL);
+			*ok = 0;
+			return NULL;
+		} else {
+			if (!type_compat(type, t->array.member, rules)) {
+				type_err(c, "error: have %1 but need %2", prog,
+				         t->array.member, rules, type);
+				*ok = 0;
+			}
+			return t->array.member;
+		}
+		break;
+
+###### interp binode cases
+	case Index: {
+		mpz_t q;
+		long i;
+
+		lleft = linterp_exec(b->left);
+		right = interp_exec(b->right);
+		mpz_init(q);
+		mpz_tdiv_q(q, mpq_numref(right.num), mpq_denref(right.num));
+		i = mpz_get_si(q);
+		mpz_clear(q);
+
+		if (i >= 0 && i < lleft->type->array.size)
+			lrv = &lleft->array.elmnts[i];
+		else
+			rv = val_init(lleft->type->array.member);
+		break;
+	}
+
 ### Finally the whole program.
 
 Somewhat reminiscent of Pascal a (current) Ocean program starts with
@@ -3416,3 +3629,24 @@ Fibonacci, and performs a binary search for a number.
 			print "Yay, I found", target
 		case GiveUp:
 			print "Closest I found was", mid
+
+		size::=55
+		list:[size]number
+		list[0] = 1234
+		for i:=1; then i = i + 1; while i < size:
+			n := list[i-1] * list[i-1]
+			list[i] = (n / 100) % 10000
+
+		print "Before sort:"
+		for i:=0; then i = i + 1; while i < size:
+			print "list[",i,"]=",list[i]
+
+		for i := 1; then i=i+1; while i < size:
+			for j:=i-1; then j=j-1; while j >= 0:
+				if list[j] > list[j+1]:
+					t:= list[j]
+					list[j] = list[j+1]
+					list[j+1] = t
+		print "After sort:"
+		for i:=0; then i = i + 1; while i < size:
+			print "list[",i,"]=",list[i]