phplogo.zhihua-lai.com)

Changes | Output | Source | Examples | Instructions

No need to install additional software at the client... The server will interpret the Logo program and generate an output.

The source code has been published at www.phpclasses.org and www.phpkode.com, GPL Licence

Do you know LOGO? If You Don't, you can visit Wikipedia for a basic knowledge. Logo is fun, i remember when i was a kid, i was first taught the LOGO , i love it ... During X-mas 2006, i had the idea of programming a basic interpreter for LOGO and finally i made it within three days.

This interpreter, however, is written in PHP. You don't need to download any software. You can just put the Logo Programs in the following textbox and click the 'Run'.

Changes Log: December Christmas, 2011: Version 0.2

save as win32 .exe support
fix the double recursion problem under PHP5 [post]
several bugs fixes and speed improvement in string analysis
add dot, dotxy, repcount, pennormal, jump, jmp, walk, turn and some other keywords

December Christmas, 2006: Version 0.1

Initial Release to www.phpclasses.org

Image Output 640x480 (16 Colors) (Need 'IFRRAME') - Right Click 'Save-As' Disabled.

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Logo Source Code Input

#640 480
/* PHP Online Interpreter
   By Dr Zhihua Lai
   doctor@zhihua-lai.com
   http://www.zhihua-lai.com/?do=Software.Logo
   note: case - insensitive
   and expressions should not contain spaces ~
*/

#  this is a comment.
;  this is also a comment.
// this is also also a comment.

//////////////////////////   Global Vars Defined ///////////////////
make "T 220     // Global Variable

//////////////////////////   Procedures ////////////////////////////
# Spiral
to spiral :size :angle // recursive function with two parameters 
  if (:size>:T) [stop]
  forward :size
  right :angle
  spiral :size+2 :angle // recursive call
end

# Tree
to tree :size // with one parameter
  if (:size<10) [stop]
  fd :size
  lt 30 tree :size*0.7  ; left branch, recursive
  rt 60 tree :size*0.7  ; right branch, recursive
  lt 30 
  bk :size
end

to spiral2 :size
  if (:size>30) [stop]  ; an exit condition
  fd :size rt 15        ; many lines of action
  spiral2 :size*1.02    ; the tailend recursive call
end

# Circles
to n_eck :ne :sz
  repeat :ne [rt 360/:ne fd :sz]
end

# Circles
to mn_eck :ne :sz
  repeat :ne [rt 360/:ne n_eck :ne :sz]
end

# Circles, Faster
to anothercircle
  repeat 36 [jump 100 arc 360 100 jmp -100 turn 10]
end

//////////////////////////   Entry Program ////////////////////////////
window           ; set the window mode
setfc :white      ; set flood colour
fill             ; fill the background
penup            ; pen up
setxy 200 -150   ; set turtle position
pd               ; pen down
setpc :black   
spiral 0 91      ; do the work
setpc :blue
pu
setxy 80 130
pd
spiral2 10
pu               ; pen up
setpc :red; 
setxy -180 -100  ; set the location
lt  :degree       ; degree is a global variable
pd               ; pen down
tree 100         ; draw a tree
hideturtle       ; ht = hide the turtle, it is actually a small circle
pu
home
pd
setpc :green
// mn_eck 36 20  ; very slow compared to the following line
anothercircle
setpc :black
pu
setxy -250 -200
pd
repeat 4 [fd 100 rt 90]
pu
setxy -200 -150
setfc :red
fill
setpc :blue       ; last pc command sets the color of text
////////////////////////////  End  //////////////////////////////////////////

Examples

repeat 5[fd 100 rt 144]
window repeat 180 [fd 500 bk 500 rt 2]
repeat 8 [repeat 20 [lt 170 fd 20 rt 170 fd 20] rt 45]
make "x 1 repeat 150 [fd :x rt 89 make "x :x+1]
repeat 8 [repeat 4 [rt 90 fd 100] bk 100 lt 45]
repeat 12 [repeat 75 [fd 100 bk 100 rt 2] fd 250]
repeat 5 [repeat 6 [fd 100 lt 72] lt 144]

#only for .EXE mode please
forever 1 [
  setpc :black
  arc 360 100
  seta :hour*30 
  setpc :red
  fd 60
  bk 60
  seta :minute*6
  setpc :blue
  fd 80
  bk 80
  seta :second*6
  setpc :green
  fd 90
  bk 90
  wait 1000
  clear
]

# hello, world
to helloworld
 hideturtle
 fd 20 left 180
 fd 40 left 180
 fd 20 right 90
 fd 20 left 90
 fd 20 left 180
 fd 40 left 90
 fd 20 left 90
 fd 20 right 90
 fd 20 right 90
 fd 10 right 90
 fd 20 left 90
 fd 10 left 90
 fd 30 left 90
 fd 40 left 180
 fd 40 left 90
 fd 20 left 90
 fd 40 left 180
 fd 40 left 90
 fd 40 left 90
 fd 20 left 90
 fd 20 left 90
 fd 20 left 90
 fd 60 left 90
 fd 40 left 180
 fd 40 left 90
 fd 20 left 90
 fd 20 left 180
 fd 20 left 90
 fd 20 left 90
 fd 40 left 180
 fd 40 left 90
 fd 40 left 90
 fd 20 left 90
 fd 20 left 90
 fd 20 left 90
 fd 40 left 90
 fd 20 right 90
 fd 20 right 90
 fd 5  left 90  
 fd 5  left 90  
 fd 25 left 180
 fd 40 left 90
 fd 40 left 90
 fd 20 left 90
 fd 20 left 90
 fd 20 left 90
 fd 20 left 90
 fd 40 left 180
 fd 40
end

lt 90 pu fd 200 pd rt 90 helloworld

Instructions

Case In-Sensitive. For Example, make "a 3 is equivant to MaKe "A 3

The Empty Spaces are used to separate the expressions. Write :X+:Y Rather than :X(SPACE)+(SPACE):Y

List of Keywords