From: NeilBrown <neil@brown.name>
Date: Wed, 1 May 2019 08:13:21 +0000 (+1000)
Subject: oceani: add "remainder" operator.
X-Git-Tag: JamisonCreek-3~30
X-Git-Url: https://ocean-lang.org/code/?p=ocean;a=commitdiff_plain;h=9b6476d3862c262532453a916c54467a350714f9

oceani: add "remainder" operator.

a % b
treats a and b as integers, does a division, and reports
the remainder.

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

diff --git a/csrc/oceani.mdc b/csrc/oceani.mdc
index 9e1ce02..68e5b60 100644
--- a/csrc/oceani.mdc
+++ b/csrc/oceani.mdc
@@ -47,7 +47,7 @@ Elements which are present to make a usable language are:
 
  - "blocks" of multiple statements.
  - `pass`: a statement which does nothing.
- - expressions: `+`, `-`, `*`, `/` can apply to numbers and `++` can
+ - expressions: `+`, `-`, `*`, `/`, `%` can apply to numbers and `++` can
    catenate strings.  `and`, `or`, `not` manipulate Booleans, and
    normal comparison operators can work on all three types.
  - `print`: will print the values in a list of expressions.
@@ -2069,7 +2069,7 @@ precedence is handled better I might be able to discard this.
 
 ###### Binode types
 	Plus, Minus,
-	Times, Divide,
+	Times, Divide, Rem,
 	Concat,
 	Absolute, Negate,
 	Bracket,
@@ -2119,6 +2119,7 @@ precedence is handled better I might be able to discard this.
 
 	Top ->    * ${ $0.op = Times; }$
 		| / ${ $0.op = Divide; }$
+		| % ${ $0.op = Rem; }$
 		| ++ ${ $0.op = Concat; }$
 
 ###### print binode cases
@@ -2127,13 +2128,15 @@ precedence is handled better I might be able to discard this.
 	case Times:
 	case Divide:
 	case Concat:
+	case Rem:
 		print_exec(b->left, indent, 0);
 		switch(b->op) {
-		case Plus:   printf(" + "); break;
-		case Minus:  printf(" - "); break;
-		case Times:  printf(" * "); break;
-		case Divide: printf(" / "); break;
-		case Concat: printf(" ++ "); break;
+		case Plus:   fputs(" + ", stdout); break;
+		case Minus:  fputs(" - ", stdout); break;
+		case Times:  fputs(" * ", stdout); break;
+		case Divide: fputs(" / ", stdout); break;
+		case Rem:    fputs(" % ", stdout); break;
+		case Concat: fputs(" ++ ", stdout); break;
 		default: abort();
 		}
 		print_exec(b->right, indent, 0);
@@ -2156,6 +2159,7 @@ precedence is handled better I might be able to discard this.
 	case Plus:
 	case Minus:
 	case Times:
+	case Rem:
 	case Divide:
 		/* both must be numbers, result is Tnum */
 	case Absolute:
@@ -2207,6 +2211,20 @@ precedence is handled better I might be able to discard this.
 		right = interp_exec(b->right);
 		mpq_div(rv.num, rv.num, right.num);
 		break;
+	case Rem: {
+		mpz_t l, r, rem;
+
+		left = interp_exec(b->left);
+		right = interp_exec(b->right);
+		mpz_init(l); mpz_init(r); mpz_init(rem);
+		mpz_tdiv_q(l, mpq_numref(left.num), mpq_denref(left.num));
+		mpz_tdiv_q(r, mpq_numref(right.num), mpq_denref(right.num));
+		mpz_tdiv_r(rem, l, r);
+		rv = val_init(Tnum);
+		mpq_set_z(rv.num, rem);
+		mpz_clear(r); mpz_clear(l); mpz_clear(rem);
+		break;
+	}
 	case Negate:
 		rv = interp_exec(b->right);
 		mpq_neg(rv.num, rv.num);