From 1cfab8d21e31bab3b903d4d7e1b20df675845384 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Hru=C5=A1ka?= <ondra@ondrovo.com>
Date: Sun, 25 Oct 2020 12:50:40 +0100
Subject: [PATCH] fix rng not being inclusive

---
 README.md              | 76 ++++++++++++++++++++++--------------------
 crsn_arith/src/exec.rs |  2 +-
 examples/flipcoin.csn  |  6 ++++
 examples/frandom.csn   |  8 +++++
 4 files changed, 55 insertions(+), 37 deletions(-)
 create mode 100644 examples/flipcoin.csn
 create mode 100644 examples/frandom.csn

diff --git a/README.md b/README.md
index d53e878..a94c1d1 100644
--- a/README.md
+++ b/README.md
@@ -557,92 +557,96 @@ Here's an abridged summary of the floating point submodule:
 (most of these support the shorthand version too - `RW` in place of `Wr Rd`)
 
 ```
-; IntToFloat
+; Convert int to float
 (itf Wr Rd)
-; FloatToInt (round)
+; Convert float to int (round)
 (fti Wr Rd)
-; FloatToInt (ceil)
+; Convert float to int (ceil)
 (ftic Wr Rd)
-; FloatToInt (floor)
+; Convert float to int (floor)
 (ftif Wr Rd)
 
-; FloatTest - nan->invalid, infinities->overflow, positive, negative, zero
+; Test properties of a float
+; Set flags:
+;   NaN -> invalid
+;   Infinities -> overflow
+;   Positive, negative, zero
 (ftst Rd)
-; FloatCompare
+; Float compare
 (fcmp Rd Rd)
-; FloatRangeTest
+; Float range test
 (fcmpr Rd Rd'min Rd'max)
 
-; FloatRng
+; FloatRng. Unlike rng, frng is exclusive in the higher bound
 (frng Wr Rd'min Rd'max)
 
 ; --- Basic float arith ---
 
-; FloatAdd
+; Float add
 (fadd Wr Rd Rd)
-; FloatSub
+; Float subtract
 (fsub Wr Rd Rd)
-; FloatMul
+; Float multiply
 (fmul Wr Rd Rd)
-; FloatPow
+; Float power
 (fpow Wr Rd Rd'pow)
-; FloatRoot
+; Float root
 (froot Wr Rd Rd'root)
-; FloatHyp
+; Float hyp - sqrt(a*a + b*b)
 (fhyp Wr Rd Rd)
-; FloatDiv
+; Float divide
 (fdiv Wr Wr'rem Rd'a Rd'div)
-; FloatMod
+; Float modulo
 (fmod Wr Rd'a Rd'div)
-; FloatAbs
+; Float abs value
 (fabs Wr Rd)
-; FloatSgn
+; Float signum (returns -1 or 1)
 (fsgn Wr Rd)
 
 ; --- Basic trig ---
 
-; FloatSin
+; Float sine
 (fsin Wr Rd)
-; FloatAsin
+; Float arcsine
 (fasin Wr Rd)
-; FloatCos
+; Float cosine
 (fcos Wr Rd)
-; FloatAcos
+; Float arccosine
 (facos Wr Rd)
-; FloatTan
+; Float tangent
 (ftan Wr Rd)
-; FloatAtan
+; Float arctangent
 (fatan Wr Rd)
-; FloatAtan2
+; Float 2-argumenmt arctangent
 (fatan2 Wr Rd'y Rd'x)
-; FloatCot
+; Float cotangent
 (fcot Wr Rd)
-; FloatAcot
+; Float arccotangent
 (facot Wr Rd)
 
 ; --- Hyperbolic trig ---
 
-; FloatHypSin
+; Float hyperbolic sine
 (fsinh Wr Rd)
-; FloatHypAsin
+; Float hyperbolic arcsine
 (fasinh Wr Rd)
-; FloatHypCos
+; Float hyperbolic cosine
 (fcosh Wr Rd)
-; FloatHypAcos
+; Float hyperbolic arccosine
 (facosh Wr Rd)
-; FloatHypTan
+; Float hyperbolic tangent
 (ftanh Wr Rd)
-; FloatHypAtan
+; Float hyperbolic arctangent
 (fatanh Wr Rd)
-; FloatHypCot
+; Float hyperbolic cotangent
 (fcoth Wr Rd)
-; FloatHypAcot
+; Float hyperbolic arccotangent
 (facoth Wr Rd)
 ```
 
 Wow, thats a lot. I didn't test many of these yet. There may be bugs.
 
-There are also some pre-defined constants: `PI`, `PI_2`, `TAU`, `E`
+There are also some pre-defined constants: `PI`, `PI_2` (½×`PI`), `TAU` (2×`PI`), `E`
 
 ## Buffers Module
 
diff --git a/crsn_arith/src/exec.rs b/crsn_arith/src/exec.rs
index 1392656..5625d5a 100644
--- a/crsn_arith/src/exec.rs
+++ b/crsn_arith/src/exec.rs
@@ -84,7 +84,7 @@ impl OpTrait for ArithOp {
                     offset + if max == u64::MAX {
                         rand::thread_rng().gen()
                     } else {
-                        rand::thread_rng().gen_range(0, max)
+                        rand::thread_rng().gen_range(0, max + 1)
                     }
                 };
                 state.write(dst, val)?;
diff --git a/examples/flipcoin.csn b/examples/flipcoin.csn
new file mode 100644
index 0000000..a42cc3c
--- /dev/null
+++ b/examples/flipcoin.csn
@@ -0,0 +1,6 @@
+(
+    (ld r0 5)
+    (:next)
+    (rng r1 0 1 (z? (lds @cout "(1€)\n")) (else? (lds @cout "(::)\n")))
+    (dec r0 (nz? (j :next)))
+)
diff --git a/examples/frandom.csn b/examples/frandom.csn
new file mode 100644
index 0000000..b0e96bd
--- /dev/null
+++ b/examples/frandom.csn
@@ -0,0 +1,8 @@
+(
+    (:loop)
+    (frng r0 0.0 1.0)
+    (fcmp r0 1.0
+        (lt? (j :loop))
+        (eq? (lds @cout "OK"))
+        (gt? (lds @cout "OVER!")))
+)