Merge pull request #3448 from andinus/master

Add Raku solution for challenge-098, challenge-090: fix file path

6 files changed, 66 insertions, 119 deletions

diff --git a/challenge-090/andinus/README b/challenge-090/andinus/README
index b662f1cb50..3b627c71f9 100644
--- a/challenge-090/andinus/README
+++ b/challenge-090/andinus/README
@@ -33,7 +33,7 @@ Table of Contents
 1.1 Raku
 ────────
 
-  • Program: <file:perl/ch-2.raku>
+  • Program: <file:raku/ch-2.raku>
 
   Start by taking `$A' & `$B' which are defined to be `Int' & positive.
   ┌────
diff --git a/challenge-090/andinus/README.org b/challenge-090/andinus/README.org
index c4f5da3378..8ebbde0e84 100644
--- a/challenge-090/andinus/README.org
+++ b/challenge-090/andinus/README.org
@@ -11,7 +11,7 @@ You are given two positive numbers $A and $B.
 Write a script to demonstrate [[https://threesixty360.wordpress.com/2009/06/09/ethiopian-multiplication/][Ethiopian Multiplication]] using the given
 numbers.
 ** Raku
-- Program: [[file:perl/ch-2.raku]]
+- Program: [[file:raku/ch-2.raku]]
 
 Start by taking =$A= & =$B= which are defined to be =Int= & positive.
 #+BEGIN_SRC raku
diff --git a/challenge-098/andinus/README b/challenge-098/andinus/README
index b662f1cb50..98fe099f22 100644
--- a/challenge-098/andinus/README
+++ b/challenge-098/andinus/README
@@ -1,95 +1,58 @@
                             ━━━━━━━━━━━━━━━
-                             CHALLENGE 090
+                             CHALLENGE 098
 
                                 Andinus
                             ━━━━━━━━━━━━━━━
 
 
-                               2020-12-08
+                               2021-02-02
 
 
 Table of Contents
 ─────────────────
 
-1. Task 2 - Ethiopian Multiplication
+1. Task 1 - Read N-characters
 .. 1. Raku
 
 
 
 
 
-1 Task 2 - Ethiopian Multiplication
-═══════════════════════════════════
+1 Task 1 - Read N-characters
+════════════════════════════
 
-  You are given two positive numbers $A and $B.
+  You are given file `$FILE'.
 
-  Write a script to demonstrate [Ethiopian Multiplication] using the
-  given numbers.
+  Create subroutine `readN($FILE, $number)' returns the first
+  n-characters and moves the pointer to the `(n+1)th' character.
 
 
-[Ethiopian Multiplication]
-<https://threesixty360.wordpress.com/2009/06/09/ethiopian-multiplication/>
-
 1.1 Raku
 ────────
 
-  • Program: <file:perl/ch-2.raku>
+  • Program: <file:raku/ch-1.raku>
 
-  Start by taking `$A' & `$B' which are defined to be `Int' & positive.
+  `readN' is defined as such:
   ┌────
-  │ sub MAIN (
-  │     #= positive numbers
-  │     Int $A is copy where * > 0,
-  │     Int $B is copy where * > 0
+  │ sub readN (
+  │     IO $file, Int $chars --> Str
   │ ) {
   │     ...
   │ }
   └────
 
-  Here's relevant part from the link that was given above:
-        Start with the two numbers on top. Halve one, ignoring any
-        remainders or fractions, and double the other, stopping
-        when you get to 1.
-
-        14 & 12 7 & 24 3 & 48 [See how I ignored the fact that
-        halving 7 leaves 1 left over?] 1 & 96 <— Stop here.
-
-        Now look at the numbers on the right. Some are across from
-        an even number: in this case, 12 is across from the
-        original 14. Ignore those, and add the rest. So we’ll add
-        24, 48, and 96, which were across from odd numbers, and
-        get 168. And that’s the product! Isn’t that cool?
+  The pointer index is stored in a state array (`%pointers'). It's
+  stores the pointer separately for each file. It's initialized with 0.
+  ┌────
+  │ # %pointers stores the pointer index.
+  │ state Int %pointers;
+  │ %pointers{$file} = 0 without %pointers{$file};
+  └────
 
-  We do the same thing & also print the instructions.
+  The pointer is updated & required string is returned.
   ┌────
-  │ my %sets;
-  │
-  │ say "Ethopian Multiplication.\n";
-  │ say "Start with $A, $B.";
-  │ say "Divide $A by 2 & multiple $B by 2 at each step.";
-  │ say "Continue until $A equals 1. Drop the remainder, both should be Integer.\n";
-  │
-  │ say "$A, $B";
-  │ while True {
-  │     %sets{$A} = $B.Int;
-  │     $A = ($A / 2).Int;
-  │     $B = ($B * 2).Int;
-  │     last if $A < 1;
-  │     say "$A, $B";
-  │ }
-  │
-  │ say "\nNow to find the product, simply add all the numbers on right side of ','.";
-  │ say "But skip those numbers which have an even number on the left side.\n";
-  │
-  │ my Int $product = 0;
-  │ for %sets.sort({.key.Int}).reverse -> $pair {
-  │     if $pair.key % 2 != 0 {
-  │         $product += $pair.value;
-  │         say "- Adding ", $pair.value, " to product.";
-  │     } else {
-  │         say "- Skipping ", $pair.value, " because ", $pair.key, " is even.";
-  │     }
+  │ with %pointers{$file} -> $idx {
+  │     %pointers{$file} += $chars;
+  │     return $file.slurp.substr($idx, $chars);
   │ }
-  │
-  │ say "\nProduct: $product";
   └────
diff --git a/challenge-098/andinus/README.org b/challenge-098/andinus/README.org
index c4f5da3378..353698db4f 100644
--- a/challenge-098/andinus/README.org
+++ b/challenge-098/andinus/README.org
@@ -2,74 +2,38 @@
 #+HTML_LINK_UP: ../index.html
 #+OPTIONS: toc:2
 #+EXPORT_FILE_NAME: index
-#+DATE: 2020-12-08
-#+TITLE: Challenge 090
+#+DATE: 2021-02-02
+#+TITLE: Challenge 098
 
-* Task 2 - Ethiopian Multiplication
-You are given two positive numbers $A and $B.
+* Task 1 - Read N-characters
+You are given file =$FILE=.
 
-Write a script to demonstrate [[https://threesixty360.wordpress.com/2009/06/09/ethiopian-multiplication/][Ethiopian Multiplication]] using the given
-numbers.
+Create subroutine =readN($FILE, $number)= returns the first n-characters
+and moves the pointer to the =(n+1)th= character.
 ** Raku
-- Program: [[file:perl/ch-2.raku]]
+- Program: [[file:raku/ch-1.raku]]
 
-Start by taking =$A= & =$B= which are defined to be =Int= & positive.
+=readN= is defined as such:
 #+BEGIN_SRC raku
-sub MAIN (
-    #= positive numbers
-    Int $A is copy where * > 0,
-    Int $B is copy where * > 0
+sub readN (
+    IO $file, Int $chars --> Str
 ) {
     ...
 }
 #+END_SRC
 
-Here's relevant part from the link that was given above:
-#+BEGIN_QUOTE
-Start with the two numbers on top. Halve one, ignoring any remainders or
-fractions, and double the other, stopping when you get to 1.
-
-14 & 12
-7 & 24
-3 & 48  [See how I ignored the fact that halving 7 leaves 1 left over?]
-1 & 96  <— Stop here.
-
-Now look at the numbers on the right. Some are across from an even
-number: in this case, 12 is across from the original 14. Ignore those,
-and add the rest. So we’ll add 24, 48, and 96, which were across from
-odd numbers, and get 168. And that’s the product! Isn’t that cool?
-#+END_QUOTE
-
-We do the same thing & also print the instructions.
+The pointer index is stored in a state array (=%pointers=). It's stores
+the pointer separately for each file. It's initialized with 0.
 #+BEGIN_SRC raku
-my %sets;
-
-say "Ethopian Multiplication.\n";
-say "Start with $A, $B.";
-say "Divide $A by 2 & multiple $B by 2 at each step.";
-say "Continue until $A equals 1. Drop the remainder, both should be Integer.\n";
-
-say "$A, $B";
-while True {
-    %sets{$A} = $B.Int;
-    $A = ($A / 2).Int;
-    $B = ($B * 2).Int;
-    last if $A < 1;
-    say "$A, $B";
-}
-
-say "\nNow to find the product, simply add all the numbers on right side of ','.";
-say "But skip those numbers which have an even number on the left side.\n";
+# %pointers stores the pointer index.
+state Int %pointers;
+%pointers{$file} = 0 without %pointers{$file};
+#+END_SRC
 
-my Int $product = 0;
-for %sets.sort({.key.Int}).reverse -> $pair {
-    if $pair.key % 2 != 0 {
-        $product += $pair.value;
-        say "- Adding ", $pair.value, " to product.";
-    } else {
-        say "- Skipping ", $pair.value, " because ", $pair.key, " is even.";
-    }
+The pointer is updated & required string is returned.
+#+BEGIN_SRC raku
+with %pointers{$file} -> $idx {
+    %pointers{$file} += $chars;
+    return $file.slurp.substr($idx, $chars);
 }
-
-say "\nProduct: $product";
 #+END_SRC
diff --git a/challenge-098/andinus/blog-1.txt b/challenge-098/andinus/blog-1.txt
new file mode 100644
index 0000000000..699ade364d
--- /dev/null
+++ b/challenge-098/andinus/blog-1.txt
@@ -0,0 +1 @@
+https://andinus.tilde.institute/pwc/challenge-098/
diff --git a/challenge-098/andinus/raku/ch-1.raku b/challenge-098/andinus/raku/ch-1.raku
new file mode 100755
index 0000000000..3ebcf32c9e
--- /dev/null
+++ b/challenge-098/andinus/raku/ch-1.raku
@@ -0,0 +1,19 @@
+#!/usr/bin/env raku
+
+use v6.d;
+
+# readN takes a file & returns the first `$chars' characters if called
+# the first time. It stores the pointer index & returns characters
+# from `$idx' to `$idx + $chars'.
+sub readN (
+    IO $file, Int $chars --> Str
+) {
+    # %pointers stores the pointer index.
+    state Int %pointers;
+    %pointers{$file} = 0 without %pointers{$file};
+
+    with %pointers{$file} -> $idx {
+        %pointers{$file} += $chars;
+        return $file.slurp.substr($idx, $chars);
+    }
+}