Finally upgraded to ROR 5 !

I’ve experimenting web developing on Ruby on Rails as a hobby. Last few days I’ve work with ruby 1.9.3 and ROR 3.2.x and felt that I must move to ruby version 2.x.x and  ROR 5 because ROR community fastly moved to new ROR version and old version is being deprecated. So here I’ve show you what is on it. Before that below screenshot shows that how the old ROR 4 start page looks like . Because I loved that very much :-).

Let’s rock on!

Here firstly I’ve fully removed ruby 1.8.7 and ROR 4 from my machine. After that I’ve installed ruby 2.2.4 and ROR 5.0.0.1

After that in the terminal I’ve issued the following command

>rails new first_app

So it creates a new rails app

Oh looo..ong Screenshot 😀

After that move to that newly created rails app folder and issue the following command in the windows or linux terminal.

first_app>rails server

After that type the following url in your web browser

http://localhost:3000/

Now you can see the browser screen as below.

Yay 😀 it rocks !

The main difference is the welcome page is been changed and it’s clean and simple .Also the web server moved to “WEBRICK” to “PUMA”.

Thats it !

 

First step to groovy on windows

Hi , I’m already refreshing my knowledge about programming languages . I’m also java a lover . So when I searched about something about java and accidentally click on a link about java run-time environment based programming languages . Bingo…! bingo..! , it is a post on groovy . So  then I read that article and got some idea about groovy.

In this post I’will explain how to prepare the basic environment to run/develop groovy on windows 64 bit editions.

First thing is to  point to below url and download the windows setup binary

groovy-lang.org/download.html

 

Before this step you must have to install proper java SE development kit . I have installed  Java SE Development Kit 8u73 64bit edition ,

Now double click and run  the setup file

In below step you will find that sometimes installer says unable to find jvm or JAVA_HOME . but ignore that and proceed to the next step.

After finishing the setup you have to modify some settings as below . Open “Advance system settings” from the windows properties and click on “Environmental Variables”

 

Then modify the settings according to the below screen shots

Then you have to copy “groovy.exe” ,”groovyw.exe” from the folder “D:\Groovy2.4.5\Supplementary\native\64bit” to to the “D:\Groovy-2.4.5\bin” because we have to run 64 bit edition of groovy . Then give the permission to overwrite and replace the files

After that move to the “D:\Groovy-2.4.5\Supplementary\JavaArch” folder using windows command prompt

Then run the command “java  -jar GetArchModel.jar”

If the result is ok you will find the following message

“Found a 64 bit java installation.”

After that close the windows command prompt and then get a new command prompt window

Then type “groovy”

If the all the settings are successful you’ll find the following screen

That’s all 🙂 !

Notice that if you are using 32 bit version of jdk and windows os  you don’t have to worry about copying “groovy.exe” ,”groovyw.exe” to the “D:\Groovy-2.4.5\bin” folder

If you have any comments let me know.It is very important!

Have a nice day 🙂 !

 

HOW TO CHECK YOUR GRAMMAR AND DFA

This is a sample tutorial describes how to check your grammar is in correct order or not and print the DFA states of your grammar using bison and flex in windows environment.

To describe the procedure I’ve got the “simple thermostat controller example” from the “Ivan’s Blog” at “http://ivan215.blogspot.com/2009/04/yacc-yet-another-compiler-compiler.html“.

First we must define our grammar in lex (*.l) and yacc (*.y) files. In this example I named them as “heat.l” and “heat.y” according to the “Ivan’s Blog” because these files are describes a process of heat equipment. (Figure 1)

Figure 1

---

heat.l

%{
#include <stdio.h>
#include "y.tab.h"
%}
%%
[0-9]+ yylval=atoi(yytext); return NUMBER;
heat return TOKHEAT;
on|off yylval=!strcmp(yytext,"on");return STATE;
target return TOKTARGET;
temperature return TOKTEMPERATURE;\n /*ignore end of line*/;
[\t]+ /*ignore whitespace*/;
%%
int yywrap(void)
{
 return 1;
}

 

---

 

heat.y

%{
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <math.h>
int lineno =1;
void yyerror(char *str);
%}
%start commands
%token NUMBER TOKHEAT STATE TOKTARGET TOKTEMPERATURE
%%
commands :/*empty*/
|commands command
;
command :heat_switch
|target_set
;
heat_switch :TOKHEAT STATE
{
if($2)
   printf("\tHeat turned on \n");
else
   printf("\tHeat turned off \n");
}
;
target_set :TOKTARGET TOKTEMPERATURE NUMBER
{
   printf("\tTemperature set to %d\n",$3);
}
;
%%
void yyerror(char *str)
{
   fprintf(stderr,"line %d: %s\n",lineno,str);
}
main()
{
   yyparse();
}

---

 

Then open a terminal and type the following command only for “heat.y” file only (Figure 2)

>bison –dv heat.y   (here the –v parameter for more details type >bison –help)

Figure 2

This will generate following output file (Figure 3)

“heat.output”

Figure 3

When we open the file using a text editor the file includes the following data

• Used and unused nonterminals.
• Used and unused terminals.
• Grammar rules.
• And the states of the Finite Automata (DFA).

heat.output

Grammar
rule 1 commands -> /* empty */
rule 2 commands -> commands command
rule 3 command -> heat_switch
rule 4 command -> target_set
rule 5 heat_switch -> TOKHEAT STATE
rule 6 target_set -> TOKTARGET TOKTEMPERATURE NUMBER
Terminals, with rules where they appear
$ (-1)
error (256)
NUMBER (257) 6
TOKHEAT (258) 5
STATE (259) 5
TOKTARGET (260) 6
TOKTEMPERATURE (261) 6
Nonterminals, with rules where they appear
commands (8)
on left: 1 2, on right: 2
command (9)
on left: 3 4, on right: 2
heat_switch (10)
on left: 5, on right: 3
target_set (11)
on left: 6, on right: 4
state 0
$default reduce using rule 1 (commands)
commands go to state 1
state 1
commands -> commands . command (rule 2)
$ go to state 10
TOKHEAT shift, and go to state 2
TOKTARGETshift, and go to state 3
command go to state 4
heat_switch go to state 5
target_set go to state 6
state 2
heat_switch -> TOKHEAT . STATE (rule 5)
STATE shift, and go to state 7
state 3
target_set -> TOKTARGET . TOKTEMPERATURE NUMBER (rule 6)
TOKTEMPERATURE shift, and go to state 8
state 4
commands -> commands command . (rule 2)
$default reduce using rule 2 (commands)
state 5
command -> heat_switch . (rule 3)
$default reduce using rule 3 (command)
state 6
command -> target_set . (rule 4)
$default reduce using rule 4 (command)
state 7
heat_switch -> TOKHEAT STATE . (rule 5)
$default reduce using rule 5 (heat_switch)
state 8
target_set -> TOKTARGET TOKTEMPERATURE . NUMBER (rule 6)
NUMBER shift, and go to state 9
state 9
target_set -> TOKTARGET TOKTEMPERATURE NUMBER . (rule 6)
$default reduce using rule 6 (target_set)
state 10
$ go to state 11
state 11
$default accept

---

 

If there is an error it will show the errors in (*.output) file as a below (Figure 4)

Figure 4

This method is briefly described in page 6 of “LEX & YACC TUTORIAL” by Tom Niemann.

Thank you!