Merge branch 'master' of git://factorcode.org/git/factor

basis/math/miller-rabin/miller-rabin.factor

@@ -1,7 +1,7 @@
 ! Copyright (C) 2008 Doug Coleman.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: combinators io locals kernel math math.functions
-math.ranges namespaces random sequences hashtables sets ;
+USING: combinators kernel locals math math.functions math.ranges
+random sequences sets ;
 IN: math.miller-rabin
 
 <PRIVATE
@@ -37,7 +37,7 @@ PRIVATE>
         { [ dup 1 <= ] [ 3drop f ] }
         { [ dup 2 = ] [ 3drop t ] }
         { [ dup even? ] [ 3drop f ] }
-        [ [ drop (miller-rabin) ] with-scope ]
+        [ drop (miller-rabin) ]
     } cond ;
 
 : miller-rabin ( n -- ? ) 10 miller-rabin* ;

core/sequences/sequences.factor

@@ -828,7 +828,7 @@ PRIVATE>
 
 : supremum ( seq -- n ) dup first [ max ] reduce ;
 
-: sigma ( seq quot -- n ) [ + ] compose 0 swap reduce ; inline
+: sigma ( seq quot -- n ) 0 -rot [ rot slip + ] curry each ; inline
 
 : count ( seq quot -- n ) [ 1 0 ? ] compose sigma ; inline
 

extra/math/primes/erato/erato.factor

@@ -8,7 +8,7 @@ IN: math.primes.erato
     2 * 3 + ; inline
 
 : mark-multiples ( i arr -- )
-    [ dup index> [ + ] keep ] dip
+    [ index> [ sq >index ] keep ] dip
     [ length 1 - swap <range> f swap ] keep
     [ set-nth ] curry with each ;
 

extra/math/primes/primes.factor

@@ -1,7 +1,7 @@
 ! Copyright (C) 2007 Samuel Tardieu.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: binary-search combinators kernel lists.lazy math math.functions
-math.miller-rabin math.primes.erato math.ranges sequences ;
+USING: combinators kernel lists.lazy math math.functions
+math.miller-rabin math.order math.primes.erato math.ranges sequences ;
 IN: math.primes
 
 <PRIVATE
@@ -28,15 +28,11 @@ PRIVATE>
 : lprimes-from ( n -- list )
     dup 3 < [ drop lprimes ] [ 1- next-prime [ next-prime ] lfrom-by ] if ;
 
-: primes-upto ( n -- seq )
-    dup 2 < [
-        drop V{ }
-    ] [
-        3 swap 2 <range> [ prime? ] filter 2 prefix
-    ] if ; foldable
-
 : primes-between ( low high -- seq )
-    primes-upto [ 1- next-prime ] dip
-    [ natural-search drop ] [ length ] [ ] tri <slice> ; foldable
+    [ dup 3 max dup even? [ 1 + ] when ] dip
+    2 <range> [ prime? ] filter
+    swap 3 < [ 2 prefix ] when ;
+
+: primes-upto ( n -- seq ) 2 swap primes-between ;
 
 : coprime? ( a b -- ? ) gcd nip 1 = ; foldable

extra/project-euler/057/057.factor

@@ -0,0 +1,43 @@
+! Copyright (c) 2008 Samuel Tardieu
+! See http://factorcode.org/license.txt for BSD license.
+USING: kernel math math.functions math.parser sequences ;
+IN: project-euler.057
+
+! http://projecteuler.net/index.php?section=problems&id=57
+
+! DESCRIPTION
+! -----------
+
+! It is possible to show that the square root of two can be expressed
+! as an infinite continued fraction.
+
+! √ 2 = 1 + 1/(2 + 1/(2 + 1/(2 + ... ))) = 1.414213...
+
+! By expanding this for the first four iterations, we get:
+
+! 1 + 1/2 = 3/2 = 1.5
+! 1 + 1/(2 + 1/2) = 7/5 = 1.4
+! 1 + 1/(2 + 1/(2 + 1/2)) = 17/12 = 1.41666...
+! 1 + 1/(2 + 1/(2 + 1/(2 + 1/2))) = 41/29 = 1.41379...
+
+! The next three expansions are 99/70, 239/169, and 577/408, but the
+! eighth expansion, 1393/985, is the first example where the number of
+! digits in the numerator exceeds the number of digits in the
+! denominator.
+
+! In the first one-thousand expansions, how many fractions contain a
+! numerator with more digits than denominator?
+
+! SOLUTION
+! --------
+
+: longer-numerator? ( seq -- ? )
+    >fraction [ number>string length ] bi@ > ; inline
+
+: euler057 ( -- answer )
+    0 1000 [ drop 2 + recip dup 1+ longer-numerator? ] count nip ;
+
+! [ euler057 ] time
+! 3.375118 seconds
+
+MAIN: euler057

extra/project-euler/project-euler.factor

@@ -15,13 +15,13 @@ USING: definitions io io.files io.pathnames kernel math math.parser
     project-euler.041 project-euler.042 project-euler.043 project-euler.044
     project-euler.045 project-euler.046 project-euler.047 project-euler.048
     project-euler.052 project-euler.053 project-euler.055 project-euler.056
-    project-euler.059 project-euler.067 project-euler.071 project-euler.073
-    project-euler.075 project-euler.076 project-euler.079 project-euler.092
-    project-euler.097 project-euler.099 project-euler.100 project-euler.116
-    project-euler.117 project-euler.134 project-euler.148 project-euler.150
-    project-euler.151 project-euler.164 project-euler.169 project-euler.173
-    project-euler.175 project-euler.186 project-euler.190 project-euler.203
-    project-euler.215 ;
+    project-euler.057 project-euler.059 project-euler.067 project-euler.071
+    project-euler.073 project-euler.075 project-euler.076 project-euler.079
+    project-euler.092 project-euler.097 project-euler.099 project-euler.100
+    project-euler.116 project-euler.117 project-euler.134 project-euler.148
+    project-euler.150 project-euler.151 project-euler.164 project-euler.169
+    project-euler.173 project-euler.175 project-euler.186 project-euler.190
+    project-euler.203 project-euler.215 ;
 IN: project-euler
 
 <PRIVATE