#Wolf ##Description Wolf is my simple programming language which is created using ANTLR parser generator. For more information about ANTLR, visit ANTLR Wikipedia. This is a effort of learning and knowing more about how languages are made by creating a simple programming language.

Input File

I am using Gradle ANTLR Plugin for build. Here we have given input file which is example.wlf in gradle.build task.

Building Parser

• To build and compile our class with our generated parser, run
  sh run.sh -b

Running Parser and getting parsed data

Get parsed data from file input

• To visualize the AST in gui, run
  sh run.sh -gui OR sh run.sh -gui filename
• To visualize AST as tokens, run
  sh run.sh -tokens OR sh run.sh -tokens filename
• To visualize AST as tree, run
  sh run.sh -tree OR sh run.sh -tree filename

Note:

In above running options filename is optional. By default above commands will take example.wlf sample file as input.

Giving input from console

• To visualize the AST in gui, run
  sh run.sh -guic
• To visualize AST as tokens, run
  sh run.sh -tokensc
• To visualize AST as tree, run
  sh run.sh -treec

Note:

After running any of the above script. It will ask for input on console. For example:

$ sh run.sh -tokensc
Enter input string to parse and press ctrl+z (Windows) or ctrl+d (Unix based OS):
12-2*(5/10)-1**2

Now press ctrl+d or ctrl+z to see the output after giving input.

[@0,0:1='12',<10>,1:0]
[@1,2:2='-',<7>,1:2]
...................
...................
[@14,17:16='<EOF>',<-1>,2:0]

By default sh run.sh without any option runs in -guic mode. Means, it will take input from console and give AST in gui.

Building language using Parser generated by ANTLR:

• We are using our generated parser in Wolf.java class. We are using EvalVisitor.java class to extend WolfBaseVisitor<Integer> class. To implement the calculator, we override the methods associated with statement and expression alternatives. To run all compiled classes along with our generated parser, run
  

$ sh run.sh -a
## Running...
Enter data and press ctrl+d(Unix based OS) or ctrl+z(Windows) to see the output:
a=4
b=10
c=a+b
b=a
c
b

Output:
14
4

OR
Now pass input from a file. Here it is example.wlf and this is the content in it:

193
a=5
b=6
a+b*2
(1+2)*3

Now run it.

$ sh run.sh -a example.wlf
## Running...
193
17
9