# 8d552510fe9d

`Problem 3, and fix up utils.`
author Steve Losh Sat, 09 Apr 2016 17:16:13 +0000 330b4236a18e a0f494350896 (none) Makefile euler.asd euler.lisp make-utilities.lisp package.lisp primes.lisp quickutils.lisp utilities.lisp utils.lisp

## Changes

```--- a/Makefile	Sat Apr 09 16:38:55 2016 +0000
+++ b/Makefile	Sat Apr 09 17:16:13 2016 +0000
@@ -1,4 +1,4 @@
.PHONY:

-utilities.lisp: make-utilities.lisp
+quickutils.lisp: make-utilities.lisp
sbcl --noinform --load make-utilities.lisp  --eval '(quit)'```
```--- a/euler.asd	Sat Apr 09 16:38:55 2016 +0000
+++ b/euler.asd	Sat Apr 09 17:16:13 2016 +0000
@@ -16,7 +16,9 @@

:serial t
-  :components ((:file "utilities") ; quickutils package ordering crap
+  :components ((:file "quickutils") ; quickutils package ordering crap
(:file "package")
+               (:file "utils")
+               (:file "primes")
(:file "euler")))
```
```--- a/euler.lisp	Sat Apr 09 16:38:55 2016 +0000
+++ b/euler.lisp	Sat Apr 09 17:16:13 2016 +0000
@@ -1,9 +1,5 @@
(in-package #:euler)

-(defun dividesp (n divisor)
-  "Return whether `n` is evenly divisible by `divisor`."
-  (zerop (mod n divisor)))
-
(defun problem-1 ()
(loop :for i :from 1 :below 1000
:when (or (dividesp i 3)
@@ -18,3 +14,5 @@
:do (psetf p n
n (+ p n))))

+(defun problem-3 ()
+  (apply #'max (prime-factorization 600851475143)))```
```--- a/make-utilities.lisp	Sat Apr 09 16:38:55 2016 +0000
+++ b/make-utilities.lisp	Sat Apr 09 17:16:13 2016 +0000
@@ -1,10 +1,11 @@

(qtlc:save-utils-as
-  "utilities.lisp"
+  "quickutils.lisp"
:utilities '(:define-constant
:switch
+               :while
:ensure-boolean
:with-gensyms
)
-  :package "EULER.UTILITIES")
+  :package "EULER.QUICKUTILS")```
```--- a/package.lisp	Sat Apr 09 16:38:55 2016 +0000
+++ b/package.lisp	Sat Apr 09 17:16:13 2016 +0000
@@ -1,2 +1,7 @@
+(defpackage #:euler.utils
+  (:use #:cl #:euler.quickutils)
+  (:export
+    #:dividesp))
+
(defpackage #:euler
-  (:use #:cl #:euler.utilities))
+  (:use #:cl #:euler.quickutils #:euler.utils))```
```--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/primes.lisp	Sat Apr 09 17:16:13 2016 +0000
@@ -0,0 +1,19 @@
+(in-package #:euler)
+
+(defun prime-factorization (n)
+  "Return the prime factors of `n`."
+  ;; from http://www.geeksforgeeks.org/print-all-prime-factors-of-a-given-number/
+  (let ((result (list)))
+    (while (evenp n) ; handle 2, the only even prime factor
+      (push 2 result)
+      (setf n (/ n 2)))
+    (loop :for i :from 3 :to (sqrt n) :by 2 ; handle odd (prime) divisors
+          :do (while (dividesp n i)
+                (push i result)
+                (setf n (/ n i))))
+    (when (> n 2) ; final check in case we ended up with a prime
+      (push n result))
+    (nreverse result)))
+
+
+```
```--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/quickutils.lisp	Sat Apr 09 17:16:13 2016 +0000
@@ -0,0 +1,172 @@
+;;;; This file was automatically generated by Quickutil.
+;;;; See http://quickutil.org for details.
+
+;;;; To regenerate:
+;;;; (qtlc:save-utils-as "quickutils.lisp" :utilities '(:DEFINE-CONSTANT :SWITCH :WHILE :ENSURE-BOOLEAN :WITH-GENSYMS) :ensure-package T :package "EULER.QUICKUTILS")
+
+  (unless (find-package "EULER.QUICKUTILS")
+    (defpackage "EULER.QUICKUTILS"
+      (:documentation "Package that contains Quickutil utility functions.")
+      (:use #:cl))))
+
+(in-package "EULER.QUICKUTILS")
+
+(when (boundp '*utilities*)
+  (setf *utilities* (union *utilities* '(:DEFINE-CONSTANT :STRING-DESIGNATOR
+                                         :WITH-GENSYMS :EXTRACT-FUNCTION-NAME
+                                         :SWITCH :UNTIL :WHILE :ENSURE-BOOLEAN))))
+
+  (defun %reevaluate-constant (name value test)
+    (if (not (boundp name))
+        value
+        (let ((old (symbol-value name))
+              (new value))
+          (if (not (constantp name))
+              (prog1 new
+                (cerror "Try to redefine the variable as a constant."
+                        "~@<~S is an already bound non-constant variable ~
+                       whose value is ~S.~:@>" name old))
+              (if (funcall test old new)
+                  old
+                  (restart-case
+                      (error "~@<~S is an already defined constant whose value ~
+                              ~S is not equal to the provided initial value ~S ~
+                              under ~S.~:@>" name old new test)
+                    (ignore ()
+                      :report "Retain the current value."
+                      old)
+                    (continue ()
+                      :report "Try to redefine the constant."
+                      new)))))))
+
+  (defmacro define-constant (name initial-value &key (test ''eql) documentation)
+    "Ensures that the global variable named by `name` is a constant with a value
+that is equal under `test` to the result of evaluating `initial-value`. `test` is a
+function designator that defaults to `eql`. If `documentation` is given, it
+becomes the documentation string of the constant.
+
+Signals an error if `name` is already a bound non-constant variable.
+
+Signals an error if `name` is already a constant variable whose value is not
+equal under `test` to result of evaluating `initial-value`."
+    `(defconstant ,name (%reevaluate-constant ',name ,initial-value ,test)
+       ,@(when documentation `(,documentation))))
+
+
+  (deftype string-designator ()
+    "A string designator type. A string designator is either a string, a symbol,
+or a character."
+    `(or symbol string character))
+
+  (defmacro with-gensyms (names &body forms)
+    "Binds each variable named by a symbol in `names` to a unique symbol around
+`forms`. Each of `names` must either be either a symbol, or of the form:
+
+    (symbol string-designator)
+
+Bare symbols appearing in `names` are equivalent to:
+
+    (symbol symbol)
+
+The string-designator is used as the argument to `gensym` when constructing the
+unique symbol the named variable will be bound to."
+    `(let ,(mapcar (lambda (name)
+                     (multiple-value-bind (symbol string)
+                         (etypecase name
+                           (symbol
+                            (values name (symbol-name name)))
+                           ((cons symbol (cons string-designator null))
+                            (values (first name) (string (second name)))))
+                       `(,symbol (gensym ,string))))
+            names)
+       ,@forms))
+
+  (defmacro with-unique-names (names &body forms)
+    "Binds each variable named by a symbol in `names` to a unique symbol around
+`forms`. Each of `names` must either be either a symbol, or of the form:
+
+    (symbol string-designator)
+
+Bare symbols appearing in `names` are equivalent to:
+
+    (symbol symbol)
+
+The string-designator is used as the argument to `gensym` when constructing the
+unique symbol the named variable will be bound to."
+    `(with-gensyms ,names ,@forms))
+  )                                        ; eval-when
+  (defun extract-function-name (spec)
+    "Useful for macros that want to mimic the functional interface for functions
+like `#'eq` and `'eq`."
+    (if (and (consp spec)
+             (member (first spec) '(quote function)))
+        (second spec)
+        spec))
+  )                                        ; eval-when
+
+    (defun generate-switch-body (whole object clauses test key &optional default)
+      (with-gensyms (value)
+        (setf test (extract-function-name test))
+        (setf key (extract-function-name key))
+        (when (and (consp default)
+                   (member (first default) '(error cerror)))
+          (setf default `(,@default "No keys match in SWITCH. Testing against ~S with ~S."
+                                    ,value ',test)))
+        `(let ((,value (,key ,object)))
+           (cond ,@(mapcar (lambda (clause)
+                             (if (member (first clause) '(t otherwise))
+                                 (progn
+                                   (when default
+                                     (error "Multiple default clauses or illegal use of a default clause in ~S."
+                                            whole))
+                                   (setf default `(progn ,@(rest clause)))
+                                   '(()))
+                                 (destructuring-bind (key-form &body forms) clause
+                                   `((,test ,value ,key-form)
+                                     ,@forms))))
+                           clauses)
+                 (t ,default))))))
+
+  (defmacro switch (&whole whole (object &key (test 'eql) (key 'identity))
+                    &body clauses)
+    "Evaluates first matching clause, returning its values, or evaluates and
+returns the values of `default` if no keys match."
+    (generate-switch-body whole object clauses test key))
+
+  (defmacro eswitch (&whole whole (object &key (test 'eql) (key 'identity))
+                     &body clauses)
+    "Like `switch`, but signals an error if no key matches."
+    (generate-switch-body whole object clauses test key '(error)))
+
+  (defmacro cswitch (&whole whole (object &key (test 'eql) (key 'identity))
+                     &body clauses)
+    "Like `switch`, but signals a continuable error if no key matches."
+    (generate-switch-body whole object clauses test key '(cerror "Return NIL from CSWITCH.")))
+
+
+  (defmacro until (expression &body body)
+    "Executes `body` until `expression` is true."
+    `(do ()
+         (,expression)
+       ,@body))
+
+
+  (defmacro while (expression &body body)
+    "Executes `body` while `expression` is true."
+    `(until (not ,expression)
+       ,@body))
+
+
+  (defun ensure-boolean (x)
+    "Convert `x` into a Boolean value."
+    (and x t))
+
+  (export '(define-constant switch eswitch cswitch while ensure-boolean
+            with-gensyms with-unique-names)))
+
+;;;; END OF quickutils.lisp ;;;;```
```--- a/utilities.lisp	Sat Apr 09 16:38:55 2016 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,159 +0,0 @@
-;;;; This file was automatically generated by Quickutil.
-;;;; See http://quickutil.org for details.
-
-;;;; To regenerate:
-;;;; (qtlc:save-utils-as "utilities.lisp" :utilities '(:DEFINE-CONSTANT :SWITCH :ENSURE-BOOLEAN :WITH-GENSYMS) :ensure-package T :package "EULER.UTILITIES")
-
-  (unless (find-package "EULER.UTILITIES")
-    (defpackage "EULER.UTILITIES"
-      (:documentation "Package that contains Quickutil utility functions.")
-      (:use #:cl))))
-
-(in-package "EULER.UTILITIES")
-
-(when (boundp '*utilities*)
-  (setf *utilities* (union *utilities* '(:DEFINE-CONSTANT :STRING-DESIGNATOR
-                                         :WITH-GENSYMS :EXTRACT-FUNCTION-NAME
-                                         :SWITCH :ENSURE-BOOLEAN))))
-
-  (defun %reevaluate-constant (name value test)
-    (if (not (boundp name))
-        value
-        (let ((old (symbol-value name))
-              (new value))
-          (if (not (constantp name))
-              (prog1 new
-                (cerror "Try to redefine the variable as a constant."
-                        "~@<~S is an already bound non-constant variable ~
-                       whose value is ~S.~:@>" name old))
-              (if (funcall test old new)
-                  old
-                  (restart-case
-                      (error "~@<~S is an already defined constant whose value ~
-                              ~S is not equal to the provided initial value ~S ~
-                              under ~S.~:@>" name old new test)
-                    (ignore ()
-                      :report "Retain the current value."
-                      old)
-                    (continue ()
-                      :report "Try to redefine the constant."
-                      new)))))))
-
-  (defmacro define-constant (name initial-value &key (test ''eql) documentation)
-    "Ensures that the global variable named by `name` is a constant with a value
-that is equal under `test` to the result of evaluating `initial-value`. `test` is a
-function designator that defaults to `eql`. If `documentation` is given, it
-becomes the documentation string of the constant.
-
-Signals an error if `name` is already a bound non-constant variable.
-
-Signals an error if `name` is already a constant variable whose value is not
-equal under `test` to result of evaluating `initial-value`."
-    `(defconstant ,name (%reevaluate-constant ',name ,initial-value ,test)
-       ,@(when documentation `(,documentation))))
-
-
-  (deftype string-designator ()
-    "A string designator type. A string designator is either a string, a symbol,
-or a character."
-    `(or symbol string character))
-
-  (defmacro with-gensyms (names &body forms)
-    "Binds each variable named by a symbol in `names` to a unique symbol around
-`forms`. Each of `names` must either be either a symbol, or of the form:
-
-    (symbol string-designator)
-
-Bare symbols appearing in `names` are equivalent to:
-
-    (symbol symbol)
-
-The string-designator is used as the argument to `gensym` when constructing the
-unique symbol the named variable will be bound to."
-    `(let ,(mapcar (lambda (name)
-                     (multiple-value-bind (symbol string)
-                         (etypecase name
-                           (symbol
-                            (values name (symbol-name name)))
-                           ((cons symbol (cons string-designator null))
-                            (values (first name) (string (second name)))))
-                       `(,symbol (gensym ,string))))
-            names)
-       ,@forms))
-
-  (defmacro with-unique-names (names &body forms)
-    "Binds each variable named by a symbol in `names` to a unique symbol around
-`forms`. Each of `names` must either be either a symbol, or of the form:
-
-    (symbol string-designator)
-
-Bare symbols appearing in `names` are equivalent to:
-
-    (symbol symbol)
-
-The string-designator is used as the argument to `gensym` when constructing the
-unique symbol the named variable will be bound to."
-    `(with-gensyms ,names ,@forms))
-  )                                        ; eval-when
-  (defun extract-function-name (spec)
-    "Useful for macros that want to mimic the functional interface for functions
-like `#'eq` and `'eq`."
-    (if (and (consp spec)
-             (member (first spec) '(quote function)))
-        (second spec)
-        spec))
-  )                                        ; eval-when
-
-    (defun generate-switch-body (whole object clauses test key &optional default)
-      (with-gensyms (value)
-        (setf test (extract-function-name test))
-        (setf key (extract-function-name key))
-        (when (and (consp default)
-                   (member (first default) '(error cerror)))
-          (setf default `(,@default "No keys match in SWITCH. Testing against ~S with ~S."
-                                    ,value ',test)))
-        `(let ((,value (,key ,object)))
-           (cond ,@(mapcar (lambda (clause)
-                             (if (member (first clause) '(t otherwise))
-                                 (progn
-                                   (when default
-                                     (error "Multiple default clauses or illegal use of a default clause in ~S."
-                                            whole))
-                                   (setf default `(progn ,@(rest clause)))
-                                   '(()))
-                                 (destructuring-bind (key-form &body forms) clause
-                                   `((,test ,value ,key-form)
-                                     ,@forms))))
-                           clauses)
-                 (t ,default))))))
-
-  (defmacro switch (&whole whole (object &key (test 'eql) (key 'identity))
-                    &body clauses)
-    "Evaluates first matching clause, returning its values, or evaluates and
-returns the values of `default` if no keys match."
-    (generate-switch-body whole object clauses test key))
-
-  (defmacro eswitch (&whole whole (object &key (test 'eql) (key 'identity))
-                     &body clauses)
-    "Like `switch`, but signals an error if no key matches."
-    (generate-switch-body whole object clauses test key '(error)))
-
-  (defmacro cswitch (&whole whole (object &key (test 'eql) (key 'identity))
-                     &body clauses)
-    "Like `switch`, but signals a continuable error if no key matches."
-    (generate-switch-body whole object clauses test key '(cerror "Return NIL from CSWITCH.")))
-
-
-  (defun ensure-boolean (x)
-    "Convert `x` into a Boolean value."
-    (and x t))
-
```--- /dev/null	Thu Jan 01 00:00:00 1970 +0000