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http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#TUSCRIPT
TUSCRIPT
  $$ MODE TUSCRIPT host=HOST ()  
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#UNIX_Shell
UNIX Shell
hostname
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#Ursa
Ursa
out (ursa.net.localhost.name) endl console
http://rosettacode.org/wiki/Identity_matrix
Identity matrix
Task Build an   identity matrix   of a size known at run-time. An identity matrix is a square matrix of size n × n, where the diagonal elements are all 1s (ones), and all the other elements are all 0s (zeroes). I n = [ 1 0 0 ⋯ 0 0 1 0 ⋯ 0 0 0 1 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ...
#Ruby
Ruby
def identity(size) Array.new(size){|i| Array.new(size){|j| i==j ? 1 : 0}} end   [4,5,6].each do |size| puts size, identity(size).map {|r| r.to_s}, "" end
http://rosettacode.org/wiki/Increment_a_numerical_string
Increment a numerical string
Task Increment a numerical string.
#XLISP
XLISP
(DEFUN INCREMENT-STRING (X) (NUMBER->STRING (+ (STRING->NUMBER X) 1)))
http://rosettacode.org/wiki/Increment_a_numerical_string
Increment a numerical string
Task Increment a numerical string.
#XPL0
XPL0
string 0; \use zero-terminated string convention code Text=12;   func StrLen(A); \Return number of characters in an ASCIIZ string char A; int I; for I:= 0 to -1>>1-1 do if A(I) = 0 then return I;   proc IncStr(S); \Increment a numeric string char S; int I; [for I:= StrLen(S)-1 do...
http://rosettacode.org/wiki/Integer_comparison
Integer comparison
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#Rockstar
Rockstar
  (Get two numbers from user) Listen to Number One Listen to Number Two (Check if n1 > n2) If Number One is greater than Number Two Say "The first is greater than the second"   (Check if n1 = n2) If Number One is Number Two Say "The Numbers are equal"   (Check if n1 < n2) If Number One is less than Number Two Say "The ...
http://rosettacode.org/wiki/Integer_comparison
Integer comparison
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#RPG
RPG
  h dftactgrp(*no)   d pi d integer1 10i 0 d integer2 10i 0   d message s 50a   if integer1 < integer2; message = 'Integer 1 is less than integer 2'; endif;   if integer1 > integer2; ...
http://rosettacode.org/wiki/HTTP
HTTP
Task Access and print a URL's content (the located resource) to the console. There is a separate task for HTTPS Requests.
#friendly_interactive_shell
friendly interactive shell
curl -s -L http://rosettacode.org/
http://rosettacode.org/wiki/HTTP
HTTP
Task Access and print a URL's content (the located resource) to the console. There is a separate task for HTTPS Requests.
#Frink
Frink
  print[read["http://frinklang.org/"]]  
http://rosettacode.org/wiki/Hofstadter-Conway_$10,000_sequence
Hofstadter-Conway $10,000 sequence
The definition of the sequence is colloquially described as:   Starting with the list [1,1],   Take the last number in the list so far: 1, I'll call it x.   Count forward x places from the beginning of the list to find the first number to add (1)   Count backward x places from the end of the list to find the secon...
#Icon_and_Unicon
Icon and Unicon
procedure main(args) m := integer(!args) | 20 nextNum := create put(A := [], 1 | 1 | |A[A[*A]]+A[-A[*A]])[*A] p2 := 2 ^ (p := 1) maxv := 0 every n := 1 to (2^m) do { if maxv <:= (x := @nextNum / real(n)) then maxm := n if x >= 0.55 then mallows := n # Want *this* n, n...
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#COBOL
COBOL
program-id. ehello. procedure division. display "Goodbye, world!" upon syserr. stop run.
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#CoffeeScript
CoffeeScript
console.warn "Goodbye, World!"
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#Common_Lisp
Common Lisp
(format *error-output* "Goodbye, world!~%")
http://rosettacode.org/wiki/Hofstadter_Q_sequence
Hofstadter Q sequence
Hofstadter Q sequence Q ( 1 ) = Q ( 2 ) = 1 , Q ( n ) = Q ( n − Q ( n − 1 ) ) + Q ( n − Q ( n − 2 ) ) , n > 2. {\displaystyle {\begin{aligned}Q(1)&=Q(2)=1,\\Q(n)&=Q{\big (}n-Q(n-1){\big )}+Q{\big (}n-Q(n-2){\big )},\quad n>2.\end{aligned}}} It is defined like the Fibonacc...
#Dart
Dart
int Q(int n) => n>2 ? Q(n-Q(n-1))+Q(n-Q(n-2)) : 1;   main() { for(int i=1;i<=10;i++) { print("Q($i)=${Q(i)}"); } print("Q(1000)=${Q(1000)}"); }
http://rosettacode.org/wiki/Hofstadter_Q_sequence
Hofstadter Q sequence
Hofstadter Q sequence Q ( 1 ) = Q ( 2 ) = 1 , Q ( n ) = Q ( n − Q ( n − 1 ) ) + Q ( n − Q ( n − 2 ) ) , n > 2. {\displaystyle {\begin{aligned}Q(1)&=Q(2)=1,\\Q(n)&=Q{\big (}n-Q(n-1){\big )}+Q{\big (}n-Q(n-2){\big )},\quad n>2.\end{aligned}}} It is defined like the Fibonacc...
#Draco
Draco
proc nonrec make_Q([*] word q) void: word n; q[1] := 1; q[2] := 1; for n from 3 upto dim(q,1)-1 do q[n] := q[n-q[n-1]] + q[n-q[n-2]] od corp   proc nonrec main() void: word MAX = 1000; word i; [MAX+1] word q; make_Q(q);   write("The first 10 terms are:"); for i from ...
http://rosettacode.org/wiki/Hickerson_series_of_almost_integers
Hickerson series of almost integers
The following function,   due to D. Hickerson,   is said to generate "Almost integers" by the "Almost Integer" page of Wolfram MathWorld,   (December 31 2013).   (See formula numbered   51.) The function is:           h ( n ) = n ! 2 ( ln ⁡ 2 ) n + 1 {\displaystyle h(n)={\operatorname {n} ! \ove...
#Nim
Nim
import strformat import bignum   let ln2 = newInt("693147180559945309417232121458") / newInt("1000000000000000000000000000000")   iterator hickerson(): tuple[n: int; val: Rat] = ## Yield the hickerson series values as rational numbers. var n = 1 num = 1 denom = 2 * ln2 * ln2 while true: yield (n, ...
http://rosettacode.org/wiki/Hickerson_series_of_almost_integers
Hickerson series of almost integers
The following function,   due to D. Hickerson,   is said to generate "Almost integers" by the "Almost Integer" page of Wolfram MathWorld,   (December 31 2013).   (See formula numbered   51.) The function is:           h ( n ) = n ! 2 ( ln ⁡ 2 ) n + 1 {\displaystyle h(n)={\operatorname {n} ! \ove...
#PARI.2FGP
PARI/GP
h(n)=n!/2/log(2)^(n+1) almost(x)=abs(x-round(x))<.1 select(n->almost(h(n)),[1..17])  
http://rosettacode.org/wiki/Hello_world/Text
Hello world/Text
Hello world/Text is part of Short Circuit's Console Program Basics selection. Task Display the string Hello world! on a text console. Related tasks   Hello world/Graphical   Hello world/Line Printer   Hello world/Newbie   Hello world/Newline omission   Hello world/Standard error   Hello world/Web server
#4DOS_Batch
4DOS Batch
echo Hello world!
http://rosettacode.org/wiki/Heronian_triangles
Heronian triangles
Hero's formula for the area of a triangle given the length of its three sides   a,   b,   and   c   is given by: A = s ( s − a ) ( s − b ) ( s − c ) , {\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},} where   s   is half the perimeter of the triangle; that is, s = a + b + c 2 . {\displaystyle s...
#D
D
import std.stdio, std.math, std.range, std.algorithm, std.numeric, std.traits, std.typecons;   double hero(in uint a, in uint b, in uint c) pure nothrow @safe @nogc { immutable s = (a + b + c) / 2.0; immutable a2 = s * (s - a) * (s - b) * (s - c); return (a2 > 0) ? a2.sqrt : 0.0; }   bool isHeronian(in uint...
http://rosettacode.org/wiki/Higher-order_functions
Higher-order functions
Task Pass a function     as an argument     to another function. Related task   First-class functions
#ATS
ATS
  #include "share/atspre_staload.hats"   fun app_to_0 (f: (int) -> int): int = f (0)   implement main0 () = { // val () = assertloc (app_to_0(lam(x) => x+1) = 1) val () = assertloc (app_to_0(lam(x) => 10*(x+1)) = 10) // } (* end of [main0] *)  
http://rosettacode.org/wiki/Hello_world/Web_server
Hello world/Web server
The browser is the new GUI ! Task Serve our standard text   Goodbye, World!   to   http://localhost:8080/   so that it can be viewed with a web browser. The provided solution must start or implement a server that accepts multiple client connections and serves text as requested. Note that starting a web browser or...
#Fantom
Fantom
using web using wisp   const class HelloMod : WebMod // provides the content { override Void onGet () { res.headers["Content-Type"] = "text/plain; charset=utf-8" res.out.print ("Goodbye, World!") } }   class HelloWeb { Void main () { WispService // creates the web service { port = 8080 ...
http://rosettacode.org/wiki/Hello_world/Web_server
Hello world/Web server
The browser is the new GUI ! Task Serve our standard text   Goodbye, World!   to   http://localhost:8080/   so that it can be viewed with a web browser. The provided solution must start or implement a server that accepts multiple client connections and serves text as requested. Note that starting a web browser or...
#Fortran
Fortran
  program http_example implicit none character (len=:), allocatable :: code character (len=:), allocatable :: command logical :: waitForProcess   ! Execute a Node.js code code = "const http = require('http'); http.createServer((req, res) => & {res.end('Hello World from a Node.js server started from...
http://rosettacode.org/wiki/Here_document
Here document
A   here document   (or "heredoc")   is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text. Depending on the language being used, a   here document   is constructed using a command followed by "<<" (or some other symbol) followed by a token string. The text ...
#Frink
Frink
  lyrics = """Oh, Danny Boy, The pipes, the pipes are calling From glen to glen and down the mountainside"""  
http://rosettacode.org/wiki/Here_document
Here document
A   here document   (or "heredoc")   is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text. Depending on the language being used, a   here document   is constructed using a command followed by "<<" (or some other symbol) followed by a token string. The text ...
#Genie
Genie
[indent=4] /* Here documents, as template and verbatim strings in Genie valac heredoc.gs */ init test:string = "Genie string"   var multilineString = """ this is a $test """   var templateString = @" this is a $test template with math for six times seven = $(6 * 7) "   stdout.printf("%s", multilineS...
http://rosettacode.org/wiki/Here_document
Here document
A   here document   (or "heredoc")   is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text. Depending on the language being used, a   here document   is constructed using a command followed by "<<" (or some other symbol) followed by a token string. The text ...
#Go
Go
var m = ` leading spaces   and blank lines`
http://rosettacode.org/wiki/Here_document
Here document
A   here document   (or "heredoc")   is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text. Depending on the language being used, a   here document   is constructed using a command followed by "<<" (or some other symbol) followed by a token string. The text ...
#Groovy
Groovy
println ''' Time's a strange fellow; more he gives than takes (and he takes all) nor any marvel finds quite disappearance but some keener makes losing, gaining --love! if a world ends '''
http://rosettacode.org/wiki/History_variables
History variables
Storing the history of objects in a program is a common task. Maintaining the history of an object in a program has traditionally required programmers either to write specific code for handling the historical data, or to use a library which supports history logging. History variables are variables in a programming la...
#Phix
Phix
without js -- (desktop/Phix only) sequence history = {} type hvt(object o) history = append(history,o) return true end type hvt test = 1 test = 2 test = 3 ?{"current",test} ?{"history",history}
http://rosettacode.org/wiki/History_variables
History variables
Storing the history of objects in a program is a common task. Maintaining the history of an object in a program has traditionally required programmers either to write specific code for handling the historical data, or to use a library which supports history logging. History variables are variables in a programming la...
#PicoLisp
PicoLisp
(de setH ("Var" Val) (when (val "Var") (with "Var" (=: history (cons @ (: history))) ) ) (set "Var" Val) )   (de restoreH ("Var") (set "Var" (pop (prop "Var" 'history))) )
http://rosettacode.org/wiki/Hofstadter_Figure-Figure_sequences
Hofstadter Figure-Figure sequences
These two sequences of positive integers are defined as: R ( 1 ) = 1   ;   S ( 1 ) = 2 R ( n ) = R ( n − 1 ) + S ( n − 1 ) , n > 1. {\displaystyle {\begin{aligned}R(1)&=1\ ;\ S(1)=2\\R(n)&=R(n-1)+S(n-1),\quad n>1.\end{aligned}}} The sequence S ( n ) {\displaystyle S(n)} is further...
#JavaScript
JavaScript
var R = [null, 1]; var S = [null, 2];   var extend_sequences = function (n) { var current = Math.max(R[R.length-1],S[S.length-1]); var i; while (R.length <= n || S.length <= n) { i = Math.min(R.length, S.length) - 1; current += 1; if (current === R[i] + S[i]) { R.push(current); } else { S.push(current)...
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation
Horner's rule for polynomial evaluation
A fast scheme for evaluating a polynomial such as: − 19 + 7 x − 4 x 2 + 6 x 3 {\displaystyle -19+7x-4x^{2}+6x^{3}\,} when x = 3 {\displaystyle x=3\;} . is to arrange the computation as follows: ( ( ( ( 0 ) x + 6 ) x + ( − 4 ) ) x + 7 ) x + ( − 19 ) {\displaystyle ((((0)x+6)x+(-4))x...
#Lambdatalk
Lambdatalk
  {def horner {def horner.r {lambda {:p :x :r} {if {A.empty? :p} then :r else {horner.r {A.rest :p} :x {+ {A.first :p} {* :x :r}}}}}} {lambda {:p :x} {horner.r {A.reverse :p} :x 0}}}   {horner {A.new -19 7 -4 6} 3} -> 128   {def φ {/ {+ 1 {sqrt 5}} 2}} = 1.618033988749895 {horner {A.new -1 -1 1} φ} -> ...
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation
Horner's rule for polynomial evaluation
A fast scheme for evaluating a polynomial such as: − 19 + 7 x − 4 x 2 + 6 x 3 {\displaystyle -19+7x-4x^{2}+6x^{3}\,} when x = 3 {\displaystyle x=3\;} . is to arrange the computation as follows: ( ( ( ( 0 ) x + 6 ) x + ( − 4 ) ) x + 7 ) x + ( − 19 ) {\displaystyle ((((0)x+6)x+(-4))x...
#Liberty_BASIC
Liberty BASIC
src$ = "Hello" coefficients$ = "-19 7 -4 6" ' list coefficients of all x^0..x^n in order x = 3 print horner(coefficients$, x) '128   print horner("4 3 2 1", 10) '1234 print horner("1 1 0 0 1", 2) '19 end   function horner(coefficients$, x) accumulator = 0 'getting length of a list requires e...
http://rosettacode.org/wiki/Hilbert_curve
Hilbert curve
Task Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
#Kotlin
Kotlin
// Version 1.2.40   data class Point(var x: Int, var y: Int)   fun d2pt(n: Int, d: Int): Point { var x = 0 var y = 0 var t = d var s = 1 while (s < n) { val rx = 1 and (t / 2) val ry = 1 and (t xor rx) val p = Point(x, y) rot(s, p, rx, ry) x = p.x + s * rx ...
http://rosettacode.org/wiki/Honeycombs
Honeycombs
The task is to produce a matrix of 20 hexagon shaped widgets in a honeycomb arrangement. The matrix should be arranged in such a manner that there are five columns of four hexagons. The hexagons in columns one, three and five are aligned horizontally, whereas the hexagons in columns two and four occupy a lower position...
#Scala
Scala
import java.awt.{BasicStroke, BorderLayout, Color, Dimension, Font, FontMetrics, Graphics, Graphics2D, Point, Polygon, RenderingHints} import java.awt.event.{KeyAdapter, KeyEvent, MouseAdapter, MouseEvent}   import javax.swing.{JFrame, JPanel}   import scala.math.{Pi, cos, sin}   object Honeycombs extends App { pri...
http://rosettacode.org/wiki/Holidays_related_to_Easter
Holidays related to Easter
Task Calculate the dates of:   Easter   Ascension Thursday   Pentecost   Trinity Sunday   Corpus Christi feast (for Catholic)   All Saints' Sunday (for Orthodox) As an example, calculate for the first year of each century from;   years     400   to   2100 CE   and for   years   2010   to   2020 CE. Note ...
#J
J
jed=:3 :0 pfm=. 21 + 30 | _4 + 19 * 1 + 19|y sn=. 6 - 7 | 4 + <.@*&1.25 y dys=. 1 40 50 50 +/~sn (] + 7 | 4 + -) pfm y,"0 1(+/\0 0 0 31 30 31 30) (I.,"0]-<:@I.{[) dys )
http://rosettacode.org/wiki/Horizontal_sundial_calculations
Horizontal sundial calculations
Task Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location. For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Island, aka Ernest Legouve Reef), wit...
#Lua
Lua
io.write("Enter latitude => ") lat = tonumber(io.read())   io.write("Enter longitude => ") lng = tonumber(io.read())   io.write("Enter legal meridian => ") ref = tonumber(io.read())   print()   slat = math.sin(math.rad(lat))   print(string.format(" sine of latitude:  %.3f", slat)) print(string.format(" ...
http://rosettacode.org/wiki/Huffman_coding
Huffman coding
Huffman encoding is a way to assign binary codes to symbols that reduces the overall number of bits used to encode a typical string of those symbols. For example, if you use letters as symbols and have details of the frequency of occurrence of those letters in typical strings, then you could just encode each letter wi...
#Phix
Phix
with javascript_semantics function store_nodes(object key, object data, integer nodes) setd({data,key},0,nodes) return 1 end function function build_freqtable(string data) integer freq = new_dict(), nodes = new_dict() for i=1 to length(data) do integer di = data[i] setd(di,...
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#Ursala
Ursala
#import cli   hostname = ~&hmh+ (ask bash)/<>+ <'hostname'>!
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#VBScript
VBScript
  Set objNetwork = CreateObject("WScript.Network") WScript.Echo objNetwork.ComputerName  
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#Vim_Script
Vim Script
echo hostname()
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#Visual_Basic
Visual Basic
Option Explicit   Private Declare Function GetComputerName Lib "kernel32.dll" Alias "GetComputerNameW" _ (ByVal lpBuffer As Long, ByRef nSize As Long) As Long   Private Const MAX_COMPUTERNAME_LENGTH As Long = 31 Private Const NO_ERR As Long = 0   Private Function Hostname() As String Dim i As Long, l As Long, s As St...
http://rosettacode.org/wiki/Identity_matrix
Identity matrix
Task Build an   identity matrix   of a size known at run-time. An identity matrix is a square matrix of size n × n, where the diagonal elements are all 1s (ones), and all the other elements are all 0s (zeroes). I n = [ 1 0 0 ⋯ 0 0 1 0 ⋯ 0 0 0 1 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ...
#Run_BASIC
Run BASIC
' formats array im() of size ims for ims = 4 to 6   print :print "--- Size: ";ims;" ---" Dim im(ims,ims)   For i = 1 To ims im(i,i) = 1 next   For row = 1 To ims print "["; cma$ = "" For col = 1 To ims print cma$;im(row, col); cma$ = ", " next print "]" next next ims
http://rosettacode.org/wiki/Increment_a_numerical_string
Increment a numerical string
Task Increment a numerical string.
#zkl
zkl
fcn numStringPlusOne(s){1+s} numStringPlusOne("123") //-->124
http://rosettacode.org/wiki/Integer_comparison
Integer comparison
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#Ruby
Ruby
a = (print "enter a value for a: "; gets).to_i b = (print "enter a value for b: "; gets).to_i   puts "#{a} is less than #{b}" if a < b puts "#{a} is greater than #{b}" if a > b puts "#{a} is equal to #{b}" if a == b
http://rosettacode.org/wiki/HTTP
HTTP
Task Access and print a URL's content (the located resource) to the console. There is a separate task for HTTPS Requests.
#Gastona
Gastona
#listix#   <main> LOOP, TEXT FILE, http://www.rosettacode.org , BODY, @<value>  
http://rosettacode.org/wiki/Hofstadter-Conway_$10,000_sequence
Hofstadter-Conway $10,000 sequence
The definition of the sequence is colloquially described as:   Starting with the list [1,1],   Take the last number in the list so far: 1, I'll call it x.   Count forward x places from the beginning of the list to find the first number to add (1)   Count backward x places from the end of the list to find the secon...
#J
J
hc10k =: , ] +/@:{~ (,&<: -.)@{: NB. Actual sequence a(n) AnN =:  % 1+i.@:# NB. a(n)/n MxAnN =: >./;.1~ 2 (=<.)@:^. 1+i.@# NB. Maxima of a(n)/n between successive powers of 2
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#D
D
import std.stdio;   void main () { stderr.writeln("Goodbye, World!"); }
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#Dart
Dart
import 'dart:io';   void main() { stderr.writeln('Goodbye, World!'); }
http://rosettacode.org/wiki/Hofstadter_Q_sequence
Hofstadter Q sequence
Hofstadter Q sequence Q ( 1 ) = Q ( 2 ) = 1 , Q ( n ) = Q ( n − Q ( n − 1 ) ) + Q ( n − Q ( n − 2 ) ) , n > 2. {\displaystyle {\begin{aligned}Q(1)&=Q(2)=1,\\Q(n)&=Q{\big (}n-Q(n-1){\big )}+Q{\big (}n-Q(n-2){\big )},\quad n>2.\end{aligned}}} It is defined like the Fibonacc...
#EchoLisp
EchoLisp
  (define RECURSE_BUMP 500) ;; minimum of chrome:500 safari:1000 firefox:2000   ;; count flips (define (flips N) (for/sum ((n (in-range 2 (1+ N)))) #:when (< (Q n) (Q (1- n))) 1))   (cache-size 120000) (define (Q n) ;; prevent browser stack overflow at low-cost (when (zero? (modulo n RECURSE_BUMP)) (for ((i (in-ra...
http://rosettacode.org/wiki/Hickerson_series_of_almost_integers
Hickerson series of almost integers
The following function,   due to D. Hickerson,   is said to generate "Almost integers" by the "Almost Integer" page of Wolfram MathWorld,   (December 31 2013).   (See formula numbered   51.) The function is:           h ( n ) = n ! 2 ( ln ⁡ 2 ) n + 1 {\displaystyle h(n)={\operatorname {n} ! \ove...
#Perl
Perl
use strict; use warnings; use Math::BigFloat;   my $iln2 = 1 / Math::BigFloat->new(2)->blog; my $h = $iln2 / 2;   for my $n ( 1 .. 17 ) { $h *= $iln2; $h *= $n; my $s = $h->copy->bfround(-3)->bstr; printf "h(%2d) = %22s is%s almost an integer.\n", $n, $s, ($s =~ /\.[09]/ ? "" : " NOT"); }  
http://rosettacode.org/wiki/Hello_world/Text
Hello world/Text
Hello world/Text is part of Short Circuit's Console Program Basics selection. Task Display the string Hello world! on a text console. Related tasks   Hello world/Graphical   Hello world/Line Printer   Hello world/Newbie   Hello world/Newline omission   Hello world/Standard error   Hello world/Web server
#6502_Assembly
6502 Assembly
; goodbyeworld.s for C= 8-bit machines, ca65 assembler format. ; String printing limited to strings of 256 characters or less.   a_cr = $0d ; Carriage return. bsout = $ffd2 ; C64 KERNEL ROM, output a character to current device. ; use $fded for Apple 2, $ffe3 (ascii) or $ffee (raw) for BBC. .code   ldx #0 ; Sta...
http://rosettacode.org/wiki/Heronian_triangles
Heronian triangles
Hero's formula for the area of a triangle given the length of its three sides   a,   b,   and   c   is given by: A = s ( s − a ) ( s − b ) ( s − c ) , {\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},} where   s   is half the perimeter of the triangle; that is, s = a + b + c 2 . {\displaystyle s...
#Delphi
Delphi
  ;; returns quintuple (A s a b c) ;; or #f if not hero (define (hero a b c (s 0) (A 0)) (when (= 1 (gcd a b c)) (set! s (// (+ a b c) 2)) (set! A (* s (- s a)(- s b)(- s c))) (when (square? A) (list (sqrt A) (* s 2) c b a))))   ;; all heroes a,b,c < sidemax ;; sorted by A|s|c & a <=b <= c (define (heroes (sid...
http://rosettacode.org/wiki/Higher-order_functions
Higher-order functions
Task Pass a function     as an argument     to another function. Related task   First-class functions
#AutoHotkey
AutoHotkey
  f(x) { return "This " . x }   g(x) { return "That " . x }   show(fun) { msgbox % %fun%("works") }   show(Func("f")) ; either create a Func object show("g") ; or just name the function return  
http://rosettacode.org/wiki/Hello_world/Web_server
Hello world/Web server
The browser is the new GUI ! Task Serve our standard text   Goodbye, World!   to   http://localhost:8080/   so that it can be viewed with a web browser. The provided solution must start or implement a server that accepts multiple client connections and serves text as requested. Note that starting a web browser or...
#Free_Pascal
Free Pascal
program HelloWorldServer; {$mode objfpc}{$H+} uses Classes, fphttpserver;   Type TTestHTTPServer = Class(TFPHTTPServer) public procedure HandleRequest(Var ARequest: TFPHTTPConnectionRequest; Var AResponse : TFPHTTPConnectionResponse); override; end;   Var Serv : TTestHTTPServer...
http://rosettacode.org/wiki/Here_document
Here document
A   here document   (or "heredoc")   is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text. Depending on the language being used, a   here document   is constructed using a command followed by "<<" (or some other symbol) followed by a token string. The text ...
#Haskell
Haskell
    main :: IO () main = do   -- multiline String putStrLn "Hello\ \ World!\n"   -- more haskell-ish way putStrLn $ unwords ["This", "is", "an", "example", "text!\n"]   -- now with multiple lines putStrLn $ unlines [ unwords ["This", "is", "the", "first" , "line."] , unwords ["...
http://rosettacode.org/wiki/Here_document
Here document
A   here document   (or "heredoc")   is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text. Depending on the language being used, a   here document   is constructed using a command followed by "<<" (or some other symbol) followed by a token string. The text ...
#J
J
here=:0 :0 0 :0 will be replaced by the text on the following lines. This is three tokens: two instances of the number 0 and one instance of the explicit definition token ':'. Any indentation in the here document will be retained in the result. There must be a space to the left of : or it will combine with th...
http://rosettacode.org/wiki/History_variables
History variables
Storing the history of objects in a program is a common task. Maintaining the history of an object in a program has traditionally required programmers either to write specific code for handling the historical data, or to use a library which supports history logging. History variables are variables in a programming la...
#PL.2FI
PL/I
  declare t float controlled;   do i = 1 to 5; /* a loop to read in and save five values. */ allocate t; get (t); end;   do while (allocation(t) > 0); /* a loop to retrieve the values. */ put (t); free t; end;  
http://rosettacode.org/wiki/History_variables
History variables
Storing the history of objects in a program is a common task. Maintaining the history of an object in a program has traditionally required programmers either to write specific code for handling the historical data, or to use a library which supports history logging. History variables are variables in a programming la...
#PureBasic
PureBasic
; integer history variable   Structure historyint List value.i() EndStructure   Procedure SetInt (*var.historyint, val.i) AddElement(*var\value())   If (ListSize(*var\value()) = 1) *var\value() = 0 AddElement(*var\value())   EndIf   *var\value() = val EndProcedure   Procedure ShowH...
http://rosettacode.org/wiki/Hofstadter_Figure-Figure_sequences
Hofstadter Figure-Figure sequences
These two sequences of positive integers are defined as: R ( 1 ) = 1   ;   S ( 1 ) = 2 R ( n ) = R ( n − 1 ) + S ( n − 1 ) , n > 1. {\displaystyle {\begin{aligned}R(1)&=1\ ;\ S(1)=2\\R(n)&=R(n-1)+S(n-1),\quad n>1.\end{aligned}}} The sequence S ( n ) {\displaystyle S(n)} is further...
#jq
jq
def init: {r: [0, 1], s: [0, 2] };   # input: {r,s} # output: {r,s,emit} where .emit is either null or the next R and where either .r or .s on output has been extended. # .emit is provided in case an unbounded stream of R values is desired. def extend_ff: (.r|length) as $rn | if .s[$rn - 1] then .emit = .r[$rn ...
http://rosettacode.org/wiki/Hofstadter_Figure-Figure_sequences
Hofstadter Figure-Figure sequences
These two sequences of positive integers are defined as: R ( 1 ) = 1   ;   S ( 1 ) = 2 R ( n ) = R ( n − 1 ) + S ( n − 1 ) , n > 1. {\displaystyle {\begin{aligned}R(1)&=1\ ;\ S(1)=2\\R(n)&=R(n-1)+S(n-1),\quad n>1.\end{aligned}}} The sequence S ( n ) {\displaystyle S(n)} is further...
#Julia
Julia
  type FigureFigure{T<:Integer} r::Array{T,1} rnmax::T snmax::T snext::T end   function grow!{T<:Integer}(ff::FigureFigure{T}, rnmax::T=100) ff.rnmax < rnmax || return nothing append!(ff.r, zeros(T, (rnmax-ff.rnmax))) snext = ff.snext for i in (ff.rnmax+1):rnmax ff.r[i] = ff.r[i-...
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation
Horner's rule for polynomial evaluation
A fast scheme for evaluating a polynomial such as: − 19 + 7 x − 4 x 2 + 6 x 3 {\displaystyle -19+7x-4x^{2}+6x^{3}\,} when x = 3 {\displaystyle x=3\;} . is to arrange the computation as follows: ( ( ( ( 0 ) x + 6 ) x + ( − 4 ) ) x + 7 ) x + ( − 19 ) {\displaystyle ((((0)x+6)x+(-4))x...
#Logo
Logo
to horner :x :coeffs if empty? :coeffs [output 0] output (first :coeffs) + (:x * horner :x bf :coeffs) end   show horner 3 [-19 7 -4 6]  ; 128
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation
Horner's rule for polynomial evaluation
A fast scheme for evaluating a polynomial such as: − 19 + 7 x − 4 x 2 + 6 x 3 {\displaystyle -19+7x-4x^{2}+6x^{3}\,} when x = 3 {\displaystyle x=3\;} . is to arrange the computation as follows: ( ( ( ( 0 ) x + 6 ) x + ( − 4 ) ) x + 7 ) x + ( − 19 ) {\displaystyle ((((0)x+6)x+(-4))x...
#Lua
Lua
function horners_rule( coeff, x ) local res = 0 for i = #coeff, 1, -1 do res = res * x + coeff[i] end return res end   x = 3 coefficients = { -19, 7, -4, 6 } print( horners_rule( coefficients, x ) )
http://rosettacode.org/wiki/Hilbert_curve
Hilbert curve
Task Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
#Lambdatalk
Lambdatalk
  1) two twinned recursive functions   {def left {lambda {:d :n} {if {< :n 1} then else T90 {right :d {- :n 1}} M:d T-90 {left  :d {- :n 1}} M:d {left  :d {- :n 1}} T-90 M:d {right :d {- :n 1}} T90}}}   {def right {lambda {:d :n} {if {< :n 1} then else T-90 {le...
http://rosettacode.org/wiki/Honeycombs
Honeycombs
The task is to produce a matrix of 20 hexagon shaped widgets in a honeycomb arrangement. The matrix should be arranged in such a manner that there are five columns of four hexagons. The hexagons in columns one, three and five are aligned horizontally, whereas the hexagons in columns two and four occupy a lower position...
#Sidef
Sidef
require('Tk')   class Honeycombs( Number size = 36, Array letters = @('A' .. 'Z').shuffle.first(20), ) {   define tk = %S<Tk> has changed = Hash()   func altitude(n) { sqrt(3/4) * n }   method polygon_coordinates(x, y, size) { var alt = altitude(size) return (x - ...
http://rosettacode.org/wiki/Holidays_related_to_Easter
Holidays related to Easter
Task Calculate the dates of:   Easter   Ascension Thursday   Pentecost   Trinity Sunday   Corpus Christi feast (for Catholic)   All Saints' Sunday (for Orthodox) As an example, calculate for the first year of each century from;   years     400   to   2100 CE   and for   years   2010   to   2020 CE. Note ...
#Java
Java
import java.text.DateFormatSymbols; import java.util.*;   public class EasterRelatedHolidays {   final static Map<String, Integer> holidayOffsets;   static { holidayOffsets = new LinkedHashMap<>(); holidayOffsets.put("Easter", 0); holidayOffsets.put("Ascension", 39); holidayOffse...
http://rosettacode.org/wiki/Horizontal_sundial_calculations
Horizontal sundial calculations
Task Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location. For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Island, aka Ernest Legouve Reef), wit...
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
lat = Input["latitude", -4.95]; lng = Input["longitude", -150.5]; ref = Input["legal meridian", -150];   slat = Sin[lat Degree]; Table[ hra = 15 h; hra -= lng - ref; hla = N@ArcTan[slat Tan[hra Degree]]/Degree; {h, hra, hla} , {h, -6, 6} ] // Prepend[{"Hour", "Sun hour angle", "Dial hour line ...
http://rosettacode.org/wiki/Horizontal_sundial_calculations
Horizontal sundial calculations
Task Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location. For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Island, aka Ernest Legouve Reef), wit...
#Microsoft_Small_Basic
Microsoft Small Basic
  TextWindow.Write("Enter latitude => ") lat = TextWindow.ReadNumber() TextWindow.Write("Enter longitude => ") lng = TextWindow.ReadNumber() TextWindow.Write("Enter legal meridian => ") ref = TextWindow.ReadNumber() sLat = Math.Sin(Math.GetRadians(lat)) TextWindow.WriteLine("") TextWindow.Write(" sine of ...
http://rosettacode.org/wiki/Huffman_coding
Huffman coding
Huffman encoding is a way to assign binary codes to symbols that reduces the overall number of bits used to encode a typical string of those symbols. For example, if you use letters as symbols and have details of the frequency of occurrence of those letters in typical strings, then you could just encode each letter wi...
#PHP
PHP
<?php function encode($symb2freq) { $heap = new SplPriorityQueue; $heap->setExtractFlags(SplPriorityQueue::EXTR_BOTH); foreach ($symb2freq as $sym => $wt) $heap->insert(array($sym => ''), -$wt);   while ($heap->count() > 1) { $lo = $heap->extract(); $hi = $heap->extract(); ...
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#Wren
Wren
/* hostname.wren */ class Host { foreign static name() // the code for this is provided by Go }   System.print(Host.name())
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#zkl
zkl
System.hostname
http://rosettacode.org/wiki/Identity_matrix
Identity matrix
Task Build an   identity matrix   of a size known at run-time. An identity matrix is a square matrix of size n × n, where the diagonal elements are all 1s (ones), and all the other elements are all 0s (zeroes). I n = [ 1 0 0 ⋯ 0 0 1 0 ⋯ 0 0 0 1 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ...
#Rust
Rust
  extern crate num; struct Matrix<T> { data: Vec<T>, size: usize, }   impl<T> Matrix<T> where T: num::Num + Clone + Copy, { fn new(size: usize) -> Self { Self { data: vec![T::zero(); size * size], size: size, } } fn get(&mut self, x: usize, y: usize) -> T ...
http://rosettacode.org/wiki/Increment_a_numerical_string
Increment a numerical string
Task Increment a numerical string.
#Zoea
Zoea
  program: increment_a_numerical_string case: 1 input: '1234' output: '1235' case: 2 input: '19' output: '20'  
http://rosettacode.org/wiki/Integer_comparison
Integer comparison
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#Run_BASIC
Run BASIC
input "1st number:"; n1 input "2nd number:"; n2   if n1 < n2 then print "1st number ";n1;" is less than 2nd number";n2 if n1 > n2 then print "1st number ";n1;" is greater than 2nd number";n2 if n1 = n2 then print "1st number ";n1;" is equal to 2nd number";n2
http://rosettacode.org/wiki/Integer_comparison
Integer comparison
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#Rust
Rust
use std::io::{self, BufRead};   fn main() { let mut reader = io::stdin(); let mut buffer = String::new(); let mut lines = reader.lock().lines().take(2); let nums: Vec<i32>= lines.map(|string| string.unwrap().trim().parse().unwrap() ).collect(); let a: i32 = nums[0]; let b: i32 = ...
http://rosettacode.org/wiki/HTTP
HTTP
Task Access and print a URL's content (the located resource) to the console. There is a separate task for HTTPS Requests.
#GML
GML
get = http_get("http://www.rosettacode.org/");
http://rosettacode.org/wiki/HTTP
HTTP
Task Access and print a URL's content (the located resource) to the console. There is a separate task for HTTPS Requests.
#Go
Go
  package main   import ( "io" "log" "net/http" "os" )   func main() { r, err := http.Get("http://rosettacode.org/robots.txt") if err != nil { log.Fatalln(err) } io.Copy(os.Stdout, r.Body) }  
http://rosettacode.org/wiki/Hofstadter-Conway_$10,000_sequence
Hofstadter-Conway $10,000 sequence
The definition of the sequence is colloquially described as:   Starting with the list [1,1],   Take the last number in the list so far: 1, I'll call it x.   Count forward x places from the beginning of the list to find the first number to add (1)   Count backward x places from the end of the list to find the secon...
#Java
Java
  // Title: Hofstadter-Conway $10,000 sequence   public class HofstadterConwaySequence {   private static int MAX = (int) Math.pow(2, 20) + 1; private static int[] HCS = new int[MAX]; static { HCS[1] = 1; HCS[2] = 1; for ( int n = 3 ; n < MAX ; n++ ) { int nm1 = HCS[n -...
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#Delphi
Delphi
program Project1;   {$APPTYPE CONSOLE}   begin WriteLn(ErrOutput, 'Goodbye, World!'); end.
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#Dylan.NET
Dylan.NET
Console::get_Error()::WriteLine("Goodbye World!")
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#D.C3.A9j.C3.A0_Vu
Déjà Vu
!write-fragment!stderr !encode!utf-8 "Goodbye, World!\n"
http://rosettacode.org/wiki/Hofstadter_Q_sequence
Hofstadter Q sequence
Hofstadter Q sequence Q ( 1 ) = Q ( 2 ) = 1 , Q ( n ) = Q ( n − Q ( n − 1 ) ) + Q ( n − Q ( n − 2 ) ) , n > 2. {\displaystyle {\begin{aligned}Q(1)&=Q(2)=1,\\Q(n)&=Q{\big (}n-Q(n-1){\big )}+Q{\big (}n-Q(n-2){\big )},\quad n>2.\end{aligned}}} It is defined like the Fibonacc...
#Eiffel
Eiffel
  class APPLICATION   create make   feature   make -- Test output of the feature hofstadter_q_sequence. local count, i: INTEGER test: ARRAY [INTEGER] do io.put_string ("%NFirst ten numbers: %N") test := hofstadter_q_sequence (10) across test as ar loop io.put_string (ar.item.out + "%...
http://rosettacode.org/wiki/Hickerson_series_of_almost_integers
Hickerson series of almost integers
The following function,   due to D. Hickerson,   is said to generate "Almost integers" by the "Almost Integer" page of Wolfram MathWorld,   (December 31 2013).   (See formula numbered   51.) The function is:           h ( n ) = n ! 2 ( ln ⁡ 2 ) n + 1 {\displaystyle h(n)={\operatorname {n} ! \ove...
#Phix
Phix
without javascript_semantics -- (no mpfr_log() for pwa/p2js) requires("1.0.0") -- (mpfr_set_default_prec[ision] renamed) include mpfr.e mpfr_set_default_precision(-23) -- (found by trial/error) mpfr ln2 = mpfr_init(2), hn = mpfr_init(0.5) mpfr_log(ln2,ln2) mpfr_div(hn,hn,ln2) for n=1 to 17 do mpfr_mul_si(hn,hn...
http://rosettacode.org/wiki/Hickerson_series_of_almost_integers
Hickerson series of almost integers
The following function,   due to D. Hickerson,   is said to generate "Almost integers" by the "Almost Integer" page of Wolfram MathWorld,   (December 31 2013).   (See formula numbered   51.) The function is:           h ( n ) = n ! 2 ( ln ⁡ 2 ) n + 1 {\displaystyle h(n)={\operatorname {n} ! \ove...
#PicoLisp
PicoLisp
  (load "@lib/misc.l")   (scl 25)   (setq LN2 0.69314718055994530941723212)   (de almost-int? (N) (bool (member (% (/ N 0.1) 10) (0 9))))   (de fmt4 (N) (format (/ N 0.0001) 4))   (de h (N) (*/ (factorial N) `(* 1.0 1.0) (* 2 (s** LN2 (inc N)))))   (de s** (A N) # scaled integer exponentiation (let R 1.0 ...
http://rosettacode.org/wiki/Hello_world/Text
Hello world/Text
Hello world/Text is part of Short Circuit's Console Program Basics selection. Task Display the string Hello world! on a text console. Related tasks   Hello world/Graphical   Hello world/Line Printer   Hello world/Newbie   Hello world/Newline omission   Hello world/Standard error   Hello world/Web server
#6800_Assembly
6800 Assembly
.cr 6800 .tf gbye6800.obj,AP1 .lf gbye6800 ;=====================================================; ; Hello world! for the Motorola 6800  ; ; by barrym 2013-03-17  ; ;-----------------------------------------------------; ; Prints the message "Hello w...
http://rosettacode.org/wiki/Heronian_triangles
Heronian triangles
Hero's formula for the area of a triangle given the length of its three sides   a,   b,   and   c   is given by: A = s ( s − a ) ( s − b ) ( s − c ) , {\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},} where   s   is half the perimeter of the triangle; that is, s = a + b + c 2 . {\displaystyle s...
#EchoLisp
EchoLisp
  ;; returns quintuple (A s a b c) ;; or #f if not hero (define (hero a b c (s 0) (A 0)) (when (= 1 (gcd a b c)) (set! s (// (+ a b c) 2)) (set! A (* s (- s a)(- s b)(- s c))) (when (square? A) (list (sqrt A) (* s 2) c b a))))   ;; all heroes a,b,c < sidemax ;; sorted by A|s|c & a <=b <= c (define (heroes (sid...
http://rosettacode.org/wiki/Higher-order_functions
Higher-order functions
Task Pass a function     as an argument     to another function. Related task   First-class functions
#BBC_BASIC
BBC BASIC
REM Test passing a function to a function: PRINT FNtwo(FNone(), 10, 11) END   REM Function to be passed: DEF FNone(x, y) = (x + y) ^ 2   REM Function taking a function as an argument: DEF FNtwo(RETURN f%, x, y) = FN(^f%)(x, y)
http://rosettacode.org/wiki/Hello_world/Web_server
Hello world/Web server
The browser is the new GUI ! Task Serve our standard text   Goodbye, World!   to   http://localhost:8080/   so that it can be viewed with a web browser. The provided solution must start or implement a server that accepts multiple client connections and serves text as requested. Note that starting a web browser or...
#FunL
FunL
native java.io.PrintWriter native java.net.ServerSocket   val port = 8080 val listener = ServerSocket( port )   printf( 'Listening at port %1$d\n', port )   forever socket = listener.accept() PrintWriter( socket.getOutputStream(), true ).println( 'hello world' ) socket.shutdownOutput() socket.close()
http://rosettacode.org/wiki/Hello_world/Web_server
Hello world/Web server
The browser is the new GUI ! Task Serve our standard text   Goodbye, World!   to   http://localhost:8080/   so that it can be viewed with a web browser. The provided solution must start or implement a server that accepts multiple client connections and serves text as requested. Note that starting a web browser or...
#Gastona
Gastona
#javaj#   <frames> oConsole   #listix#   <main> MICOHTTP, START, myServer, 8080   <GET /> //<html><body> // Goodbye world! //</body></html>  
http://rosettacode.org/wiki/Here_document
Here document
A   here document   (or "heredoc")   is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text. Depending on the language being used, a   here document   is constructed using a command followed by "<<" (or some other symbol) followed by a token string. The text ...
#JavaScript
JavaScript
const myVar = 123; const tempLit = `Here is some multi-line string. And here is the value of "myVar": ${myVar} That's all.`; console.log(tempLit)
http://rosettacode.org/wiki/Here_document
Here document
A   here document   (or "heredoc")   is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text. Depending on the language being used, a   here document   is constructed using a command followed by "<<" (or some other symbol) followed by a token string. The text ...
#jq
jq
  def s: "x y z";   s
http://rosettacode.org/wiki/Here_document
Here document
A   here document   (or "heredoc")   is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text. Depending on the language being used, a   here document   is constructed using a command followed by "<<" (or some other symbol) followed by a token string. The text ...
#Julia
Julia
print("""\ Usage: thingy [OPTIONS] -h Display this usage message -H hostname Hostname to connect to """)
http://rosettacode.org/wiki/Here_document
Here document
A   here document   (or "heredoc")   is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text. Depending on the language being used, a   here document   is constructed using a command followed by "<<" (or some other symbol) followed by a token string. The text ...
#Kotlin
Kotlin
// version 1.1.0   fun main(args: Array<String>) { val ev = "embed variables"   val here = """ This is a raw string literal which does not treat escaped characters (\t, \b, \n, \r, \', \", \\, \$ and \u) specially and can contain new lines, ...
http://rosettacode.org/wiki/History_variables
History variables
Storing the history of objects in a program is a common task. Maintaining the history of an object in a program has traditionally required programmers either to write specific code for handling the historical data, or to use a library which supports history logging. History variables are variables in a programming la...
#Python
Python
import sys   HIST = {}   def trace(frame, event, arg): for name,val in frame.f_locals.items(): if name not in HIST: HIST[name] = [] else: if HIST[name][-1] is val: continue HIST[name].append(val) return trace   def undo(name): HIST[name].pop(-1...
http://rosettacode.org/wiki/History_variables
History variables
Storing the history of objects in a program is a common task. Maintaining the history of an object in a program has traditionally required programmers either to write specific code for handling the historical data, or to use a library which supports history logging. History variables are variables in a programming la...
#Quackery
Quackery
/O> [ stack ] is x ... 3 x put ... 4 x put ... 5 x put ... x behead drop echo cr ... x take echo cr ... x take echo cr ... x take echo cr ... [ 3 4 5 ] 5 4 3
http://rosettacode.org/wiki/Hofstadter_Figure-Figure_sequences
Hofstadter Figure-Figure sequences
These two sequences of positive integers are defined as: R ( 1 ) = 1   ;   S ( 1 ) = 2 R ( n ) = R ( n − 1 ) + S ( n − 1 ) , n > 1. {\displaystyle {\begin{aligned}R(1)&=1\ ;\ S(1)=2\\R(n)&=R(n-1)+S(n-1),\quad n>1.\end{aligned}}} The sequence S ( n ) {\displaystyle S(n)} is further...
#Kotlin
Kotlin
fun ffr(n: Int) = get(n, 0)[n - 1]   fun ffs(n: Int) = get(0, n)[n - 1]   internal fun get(rSize: Int, sSize: Int): List<Int> { val rlist = arrayListOf(1, 3, 7) val slist = arrayListOf(2, 4, 5, 6) val list = if (rSize > 0) rlist else slist val targetSize = if (rSize > 0) rSize else sSize   while (li...
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation
Horner's rule for polynomial evaluation
A fast scheme for evaluating a polynomial such as: − 19 + 7 x − 4 x 2 + 6 x 3 {\displaystyle -19+7x-4x^{2}+6x^{3}\,} when x = 3 {\displaystyle x=3\;} . is to arrange the computation as follows: ( ( ( ( 0 ) x + 6 ) x + ( − 4 ) ) x + 7 ) x + ( − 19 ) {\displaystyle ((((0)x+6)x+(-4))x...
#Maple
Maple
  applyhorner:=(L::list,x)->foldl((s,t)->s*x+t,op(ListTools:-Reverse(L))):   applyhorner([-19,7,-4,6],x);   applyhorner([-19,7,-4,6],3);  
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation
Horner's rule for polynomial evaluation
A fast scheme for evaluating a polynomial such as: − 19 + 7 x − 4 x 2 + 6 x 3 {\displaystyle -19+7x-4x^{2}+6x^{3}\,} when x = 3 {\displaystyle x=3\;} . is to arrange the computation as follows: ( ( ( ( 0 ) x + 6 ) x + ( − 4 ) ) x + 7 ) x + ( − 19 ) {\displaystyle ((((0)x+6)x+(-4))x...
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
Horner[l_List, x_] := Fold[x #1 + #2 &, 0, l] Horner[{6, -4, 7, -19}, x] -> -19 + x (7 + x (-4 + 6 x))   -19 + x (7 + x (-4 + 6 x)) /. x -> 3 -> 128
http://rosettacode.org/wiki/Hilbert_curve
Hilbert curve
Task Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
#Lua
Lua
-- any version from LuaJIT 2.0/5.1, Lua 5.2, Lua 5.3 to LuaJIT 2.1.0-beta3-readline local bit=bit32 or bit -- Lua 5.2/5.3 compatibilty -- Hilbert curve implemented by Lindenmayer system function string.hilbert(s, n) for i=1,n do s=s:gsub("[AB]",function(c) if c=="A" then c="-BF+AFA+FB-" else c="+AF-BF...
http://rosettacode.org/wiki/Honeycombs
Honeycombs
The task is to produce a matrix of 20 hexagon shaped widgets in a honeycomb arrangement. The matrix should be arranged in such a manner that there are five columns of four hexagons. The hexagons in columns one, three and five are aligned horizontally, whereas the hexagons in columns two and four occupy a lower position...
#Tcl
Tcl
package require Tcl 8.5 package require Tk   # How to make a honeycomb proc honeycomb {w letterpattern} { canvas $w -width 500 -height 470 set basey 10 foreach row $letterpattern { set basex 10 set majoroffsety 0 foreach letter $row { set x [expr {$basex + 60}] set y [expr {$basey + 50 + $major...
http://rosettacode.org/wiki/Holidays_related_to_Easter
Holidays related to Easter
Task Calculate the dates of:   Easter   Ascension Thursday   Pentecost   Trinity Sunday   Corpus Christi feast (for Catholic)   All Saints' Sunday (for Orthodox) As an example, calculate for the first year of each century from;   years     400   to   2100 CE   and for   years   2010   to   2020 CE. Note ...
#JavaScript
JavaScript
const Пасха = год => { let дата = (год % 19 * 19 + 15) % 30; дата += (год % 4 * 2 + год % 7 * 4 + 6 * дата + 6) % 7; if (год >= 1918) дата += (год / 100 | 0) - (год / 400 | 0) - 2; return new Date(год, 2, 22 + дата); };   for (let год = 400; год <= 2100; год += год < 2000 ? 100 : год >= 2020 ? 80 : год < 2010 ? 10 ...