✨ feat(Integer): Add sign testing convenience methods.

Author: make-github-pseudonymous-again

src/Integer.js

@@ -366,10 +366,26 @@ export class Integer {
 		return eq( this.limbs , 0 , this.limbs.length , [ 1 ] , 0 , 1 ) ;
 	}
 
-	nonzero ( ) {
+	isnonzero ( ) {
 		return !this.iszero();
 	}
 
+	isnegative ( ) {
+		return this.is_negative ;
+	}
+
+	ispositive ( ) {
+		return this.sign() > 0 ;
+	}
+
+	isnonnegative ( ) {
+		return !this.negative();
+	}
+
+	isnonpositive ( ) {
+		return !this.positive() ;
+	}
+
 	parity ( ) {
 		// TODO optimize this, there is a much faster way to test for parity
 		// when the base is a multiple of two

test/src/Integer/isnonzero.js

@@ -0,0 +1,19 @@
+import test from 'ava' ;
+import { ZZ } from '../../../src' ;
+
+test( 'ZZ.$0().isnonzero()' , t => { t.is( ZZ.$0().isnonzero() , false  ) ; } ) ;
+test( 'ZZ.$1().isnonzero()' , t => { t.is( ZZ.$1().isnonzero() , true ) ; } ) ;
+
+test( 'ZZ.from(-2).isnonzero()' , t => { t.is( ZZ.from(-2).isnonzero() , true ) ; } ) ;
+test( 'ZZ.from(-1).isnonzero()' , t => { t.is( ZZ.from(-1).isnonzero() , true ) ; } ) ;
+test( 'ZZ.from(0).isnonzero()'  , t => { t.is( ZZ.from(0).isnonzero()  , false  ) ; } ) ;
+test( 'ZZ.from(-0).isnonzero()' , t => { t.is( ZZ.from(-0).isnonzero() , false  ) ; } ) ;
+test( 'ZZ.from(1).isnonzero()'  , t => { t.is( ZZ.from(1).isnonzero()  , true ) ; } ) ;
+test( 'ZZ.from(2).isnonzero()'  , t => { t.is( ZZ.from(2).isnonzero()  , true ) ; } ) ;
+
+test( 'ZZ.from("-2").isnonzero()' , t => { t.is( ZZ.from("-2").isnonzero() , true ) ; } ) ;
+test( 'ZZ.from("-1").isnonzero()' , t => { t.is( ZZ.from("-1").isnonzero() , true ) ; } ) ;
+test( 'ZZ.from("0").isnonzero()'  , t => { t.is( ZZ.from("0").isnonzero()  , false  ) ; } ) ;
+test( 'ZZ.from("-0").isnonzero()' , t => { t.is( ZZ.from("-0").isnonzero() , false  ) ; } ) ;
+test( 'ZZ.from("1").isnonzero()'  , t => { t.is( ZZ.from("1").isnonzero()  , true ) ; } ) ;
+test( 'ZZ.from("2").isnonzero()'  , t => { t.is( ZZ.from("2").isnonzero()  , true ) ; } ) ;