From d6b7f0ad9e7a07cdd8295083e1c737a7bf0c6305 Mon Sep 17 00:00:00 2001
From: JamesP <jlp765@gmail.com>
Date: Thu, 1 Oct 2015 15:02:46 +1000
Subject: [PATCH 1/3] add assertion for zero denominator

---
 lib/pure/rationals.nim | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/pure/rationals.nim b/lib/pure/rationals.nim
index 60d09c71a..79dc6de16 100644
--- a/lib/pure/rationals.nim
+++ b/lib/pure/rationals.nim
@@ -20,6 +20,7 @@ type Rational*[T] = object
 
 proc initRational*[T](num, den: T): Rational[T] =
   ## Create a new rational number.
+  assert(den != 0, "a denominator of zero value is invalid")
   result.num = num
   result.den = den
 

From 2f4cc4efce714f036018107f73cf1f5db40cbffd Mon Sep 17 00:00:00 2001
From: JamesP <jlp765@gmail.com>
Date: Thu, 1 Oct 2015 15:07:23 +1000
Subject: [PATCH 2/3] add a few type checks to limit type to SomeInteger

(adding a compund type to the Rational type definition
made it too difficult to define new variables
using integer literals)
---
 lib/pure/rationals.nim | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/pure/rationals.nim b/lib/pure/rationals.nim
index 79dc6de16..7d9241412 100644
--- a/lib/pure/rationals.nim
+++ b/lib/pure/rationals.nim
@@ -18,7 +18,7 @@ type Rational*[T] = object
   ## a rational number, consisting of a numerator and denominator
   num*, den*: T
 
-proc initRational*[T](num, den: T): Rational[T] =
+proc initRational*[T:SomeInteger](num, den: T): Rational[T] =
   ## Create a new rational number.
   assert(den != 0, "a denominator of zero value is invalid")
   result.num = num
@@ -34,7 +34,7 @@ proc `$`*[T](x: Rational[T]): string =
   ## Turn a rational number into a string.
   result = $x.num & "/" & $x.den
 
-proc toRational*[T](x: T): Rational[T] =
+proc toRational*[T:SomeInteger](x: T): Rational[T] =
   ## Convert some integer `x` to a rational number.
   result.num = x
   result.den = 1
@@ -48,7 +48,7 @@ proc toInt*[T](x: Rational[T]): int =
   ## `x` does not contain an integer value.
   x.num div x.den
 
-proc reduce*[T](x: var Rational[T]) =
+proc reduce*[T:SomeInteger](x: var Rational[T]) =
   ## Reduce rational `x`.
   let common = gcd(x.num, x.den)
   if x.den > 0:

From ce18b85d2cfa89a148c9530ac654605475f19a73 Mon Sep 17 00:00:00 2001
From: JamesP <jlp765@gmail.com>
Date: Thu, 1 Oct 2015 20:32:49 +1000
Subject: [PATCH 3/3] add two test: zero denominator assert fail, float type
 compile failure

---
 tests/rational/trat_float.nim |  9 +++++++++
 tests/rational/trat_init.nim  | 10 ++++++++++
 2 files changed, 19 insertions(+)
 create mode 100644 tests/rational/trat_float.nim
 create mode 100644 tests/rational/trat_init.nim

diff --git a/tests/rational/trat_float.nim b/tests/rational/trat_float.nim
new file mode 100644
index 000000000..24797c4a0
--- /dev/null
+++ b/tests/rational/trat_float.nim
@@ -0,0 +1,9 @@
+discard """
+  file: "trat_float.nim"
+  line: "9,19"
+  errormsg: '''type mismatch: got'''
+"""
+import rationals
+var
+  # this fails - no floats as num or den
+  r = initRational(1.0'f, 1.0'f)
diff --git a/tests/rational/trat_init.nim b/tests/rational/trat_init.nim
new file mode 100644
index 000000000..df29ff6e3
--- /dev/null
+++ b/tests/rational/trat_init.nim
@@ -0,0 +1,10 @@
+discard """
+  file: "trat_init.nim"
+  exitcode: "1"
+"""
+import rationals
+var
+  z = Rational[int](num: 0, den: 1)
+  o = initRational(num=1, den=1)
+  a = initRational(1, 2)
+  r = initRational(1, 0)  # this fails - no zero denominator