[rasty_ytsar]

Sample Program:
* my first program in CFPL
VAR abc, b, c AS INT
VAR x, w_23=’w’ AS CHAR
VAR t=”TRUE” AS BOOL
START
abc=b=10
w_23=’a’
* this is a comment
OUTPUT: abc & “hi” & b & “#” & w_23 & “[#]”
STOP

Output of the sample program:
10hi10
a#


Language Grammar

Program Structure:
- every line contains a single statement
- all variable declaration is found on top of the program
- a line that starts with asterisk(*) is considered as a comment and comment can be found in any part of the program
- executable code should be found inside the START and STOP block
- all reserved words are in capital letters
- sharp sign(#) signifies next line or carriage return
- ampersand(&) serves as a concatenator
- the square braces([]) are as escape code

Data Types:
1. INT – an ordinary number with no decimal part. It uses 32 bits. It can be positive or negative.
2. CHAR – a single symbol. It uses UNICODE.
3. BOOL – represents the literals true or false.
4. FLOAT – a number with decimal part. It uses 64 bits.

Operators:
Arithmetic operators
( ) - parenthesis
*, /, % - multiplication, division, modulo
+, - - addition, subtraction
>, < - greater than, lesser than
>=, <= - greater than or equal to, lesser than or equal to
==, <> - equal, not equal

Logical operators (<BOOL expression><LogicalOperator><BOOL expression>)
AND - needs the two BOOL expression to be true to result to true, else false
OR - if one of the BOOL expressions evaluates to true, returns true, else false
NOT - the reverse value of the BOOL value

Unary operator
+ - positive
- - negative


Sample Programs

1. A program with arithmetic operation
VAR xyz, abc=100 AS INT
START
xyz= ((abc *5)/10 + 10) * -1
* xyz should have the value -60
OUTPUT: “[[]” & xyz & “[]]”
STOP
Output of the sample program:
[-60]

2. A program with logical operation
VAR a=100, b=200, c=300 AS INT
VAR d=”FALSE” AS BOOL
START
d = (a < b AND c <>200)
OUTPUT: d
STOP
Output of the sample program:
TRUE

------------------------------------------------------------
please give your ideas on how to attach this... specially converting finite automata to codes

[cipher_nemo]

1.) This isn't C#
2.) Please use the CODE tags around code.

[eclipsed4utoo]

so let me guess, you have this assignment for school and you want us to do it for you?

[programble]

Usually you ask a question in a new topic...

[eclipsed4utoo]

programble, on 30 Mar, 2009 - 02:49 PM, said:

Usually you ask a question in a new topic...

I would assume this is his question...

'please give your ideas on how to attach this... specially converting finite automata to codes "

[programble]

eclipsed4utoo, on 30 Mar, 2009 - 01:59 PM, said:

programble, on 30 Mar, 2009 - 02:49 PM, said:

Usually you ask a question in a new topic...

I would assume this is his question...

'please give your ideas on how to attach this... specially converting finite automata to codes "

Right... But what does it mean?

[eclipsed4utoo]

programble, on 30 Mar, 2009 - 03:06 PM, said:

eclipsed4utoo, on 30 Mar, 2009 - 01:59 PM, said:

programble, on 30 Mar, 2009 - 02:49 PM, said:

Usually you ask a question in a new topic...

I would assume this is his question...

'please give your ideas on how to attach this... specially converting finite automata to codes "

Right... But what does it mean?

No idea.

[rasty_ytsar]

What does it mean?

I have to create an interpreter using C#, the codes that i gave are sample codes that will be interpreted, we will making a UI that accepts that sample codes, prompts an error if there is and prints/outputs the result if the syntax of the codes based from the given specification is correct. Lastly, it will generate a symbol table.

I want to know how to attack this problem.

I am not asking for the actual answer/codes, i want to know how to make the answers.

e.g. how to create a DFA to a code

a simple example will do.

- THANKS FOR THE TIME.

[programble]

Parse the code using regex...

[fremgenc]

first, read in the file
then start line by line:

VAR abc, b, c AS INT

would translate to C# as

int abc, b, c;

I was thinking of writing a Java -> C# converter. The hardest part of top layer interpreters, especially between languages, is the library references.

[Amrykid]

fremgenc, on 1 Apr, 2009 - 08:06 PM, said:

first, read in the file
then start line by line:

VAR abc, b, c AS INT

would translate to C# as

int abc, b, c;

I was thinking of writing a Java -> C# converter. The hardest part of top layer interpreters, especially between languages, is the library references.

you could use a streamreader that reads the file line by line and parse each line using string.replace/string.contains, etc.

[programble]

Amrykid, on 2 Apr, 2009 - 06:35 AM, said:

fremgenc, on 1 Apr, 2009 - 08:06 PM, said:

first, read in the file
then start line by line:

VAR abc, b, c AS INT

would translate to C# as

int abc, b, c;

I was thinking of writing a Java -> C# converter. The hardest part of top layer interpreters, especially between languages, is the library references.

you could use a streamreader that reads the file line by line and parse each line using string.replace/string.contains, etc.

Or Regex.

[egof]

Sounds like your trying to build a lexigraphic analyzer. Have you looked up lexx and Yacc?

[rasty_ytsar]

Thanks to all.

I have figured it out and passed the project.

I have to read the file, and read it line by line and read it word per word using some delimeters and using REGEX from the C#, I was able to parse it and able to identify the tokens as identifiers, keyword, etc. Using the DFA, i was able to have the state transitions to check the validity of the line and execute the line if validated correct by converting it to a C# code.