Merge: lib/standard/math: Added round method to floats

Yes, I know, it can be done right now using a simple trick like `1.34.to_i.to_f`, but it seems counter-intuitive to me, why not have a round method in Float (besides, it should be a bit faster) ?

I leave it to you, is it worth it to add this to standard ?

If it is, well +1 and let's merge this :)

Pull-Request: #924
Reviewed-by: Jean Privat <jean@pryen.org>
Reviewed-by: Alexis Laferrière <alexis.laf@xymus.net>

diff --git a/lib/standard/kernel.nit b/lib/standard/kernel.nit
index 2e9c9ae..2f2df4b 100644 (file)
--- a/lib/standard/kernel.nit
+++ b/lib/standard/kernel.nit
@@ -331,6 +331,21 @@ universal Float
                end
        end
 
+       # Compare float numbers with a given precision.
+       #
+       # Because of the loss of precision in floating numbers,
+       # the `==` method is often not the best way to compare them.
+       #
+       # ~~~
+       # assert 0.01.is_approx(0.02, 0.1)   == true
+       # assert 0.01.is_approx(0.02, 0.001) == false
+       # ~~~
+       fun is_approx(other, precision: Float): Bool
+       do
+               assert precision >= 0.0
+               return self <= other + precision and self >= other - precision
+       end
+
        redef fun max(other)
        do
                if self < other then

diff --git a/tests/sav/nitg-e/fixme/base_gen_reassign_alt4.res b/tests/sav/nitg-e/fixme/base_gen_reassign_alt4.res
index 56621b6..8229d05 100644 (file)
--- a/tests/sav/nitg-e/fixme/base_gen_reassign_alt4.res
+++ b/tests/sav/nitg-e/fixme/base_gen_reassign_alt4.res
@@ -1,4 +1,4 @@
-Runtime error: Cast failed. Expected `OTHER`, got `Float` (../lib/standard/kernel.nit:374)
+Runtime error: Cast failed. Expected `OTHER`, got `Float` (../lib/standard/kernel.nit:389)
 11
 21
 31

diff --git a/tests/sav/nitg-e/fixme/base_gen_reassign_alt5.res b/tests/sav/nitg-e/fixme/base_gen_reassign_alt5.res
index 56621b6..8229d05 100644 (file)
--- a/tests/sav/nitg-e/fixme/base_gen_reassign_alt5.res
+++ b/tests/sav/nitg-e/fixme/base_gen_reassign_alt5.res
@@ -1,4 +1,4 @@
-Runtime error: Cast failed. Expected `OTHER`, got `Float` (../lib/standard/kernel.nit:374)
+Runtime error: Cast failed. Expected `OTHER`, got `Float` (../lib/standard/kernel.nit:389)
 11
 21
 31

diff --git a/tests/sav/nitg-e/fixme/base_gen_reassign_alt6.res b/tests/sav/nitg-e/fixme/base_gen_reassign_alt6.res
index 56621b6..8229d05 100644 (file)
--- a/tests/sav/nitg-e/fixme/base_gen_reassign_alt6.res
+++ b/tests/sav/nitg-e/fixme/base_gen_reassign_alt6.res
@@ -1,4 +1,4 @@
-Runtime error: Cast failed. Expected `OTHER`, got `Float` (../lib/standard/kernel.nit:374)
+Runtime error: Cast failed. Expected `OTHER`, got `Float` (../lib/standard/kernel.nit:389)
 11
 21
 31

diff --git a/tests/sav/nituml_args3.res b/tests/sav/nituml_args3.res
index af28f14..e248df6 100644 (file)
--- a/tests/sav/nituml_args3.res
+++ b/tests/sav/nituml_args3.res
@@ -41,7 +41,7 @@ Bool [
 Object -> Bool [dir=back arrowtail=open style=dashed];
 
 Float [
- label = "{Float||}"
+ label = "{Float||+ is_approx(other: Float, precision: Float): Bool\l}"
 ]
 Numeric -> Float [dir=back arrowtail=open style=dashed];
 

diff --git a/tests/sav/nituml_args4.res b/tests/sav/nituml_args4.res
index 6189897..9a7b30f 100644 (file)
--- a/tests/sav/nituml_args4.res
+++ b/tests/sav/nituml_args4.res
@@ -41,7 +41,7 @@ Bool [
 Object -> Bool [dir=back arrowtail=open style=dashed];
 
 Float [
- label = "{Float||}"
+ label = "{Float||+ is_approx(other: Float, precision: Float): Bool\l}"
 ]
 Numeric -> Float [dir=back arrowtail=open style=dashed];