Author: Hafez Irshaid [email protected].
I had some free time so I decided to develop my own programming language for fun only. This programming language might have some issues, I will continue to fix them on my free time.
This language doesn't generate binary or machine code nor it does convert code into assembly language. It executes the code by emulating my own instruction set.
if, elseif, else, fi, for, while, endfor, endwhile, echo, break, print
python3 asl.py --filename filename.asl
filename.asl is the input source file asl.py is the main file.
echo "while loop"
i = 0
end = 50
while (i <= end)
if ((i % 2) == 0)
echo "{i} is even"
else
echo "{i} is odd"
fi
i = i + 1
endwhile
echo "testing for loop"
for (var = 1; var <= 10; var = var + 1)
if ((var % 2) == 0)
echo "{var} is even"
else
echo "{var} is odd"
fi
endfor- [x] Variable types(number, string)
- [x] String comparison
- [ ] functions (methods) calls
- [ ] Arrays and lists
- [x] Signed number comparisons - sign minus
- [ ] handle ++ and --
- [ ] Enhanced Syntax Error Checking
- [ ] Enhance expression evaluator to take priority
- [ ] Implement ! operation
- [ ] Implement exec command on shell
exec "ls -l"
should execute ls -l command on the shell
- [ ] Implement Unit Testing.
- [ ] Enhance Expression Parsing.
------------- -------------- ---------------- ----------------- ----------------
| | | | | | | | | |
------| Lexer |------| Parser |------| Compiler |------| Generator |------| Executor |------> Program Output
| | | | | | | | | | | | | | |
| ------------- | -------------- | ---------------- | ----------------- | ----------------
| | | | |
\ / \ / \ / \ / \ /
Input List of list of Execution List of
File tokens statements Tree Instructions
Lexer: Converts code texts into meaningful lexemes to tokens
Parser: Convert list of tokens into statements and extract their attributes
Compiler: Compiles list of statements into execution tree
Generator: Converts execution tree into executable instructions list
Executor: Contains methods to execute list of instructions to produce program logical output
Expression Evaluator:
| Token Type | Regular Expression |
|---|---|
| COMMENT | (/*([^*] |
| CALL | ^call |
| METHOD | ^method |
| ELIF | ^elif |
| IF | ^if |
| ELSE | ^else |
| FI | ^fi |
| FI | ^endif |
| ENDFOR | ^endfor |
| ENDWHILE | ^endwhile |
| BREAK | ^break |
| CONTINUE | ^continue |
| FOR | ^for |
| WHILE | ^while |
| STRUCT | ^struct |
| ENDSTRUCT | ^endstruct |
| ECHO | ^echo |
| INPUT | ^input |
| RETURN | ^return |
| TRUE | ^true |
| FALSE | ^false |
| IDENTIFICATIONBETWEENBRSCKETS | {.*?} |
| IDENTIFICATION | ^[a-zA-Z_$][a-zA-Z_$0-9]* |
| STRING | ^"[^"]*" |
| REAL | [0-9]+.[0-9]* |
| NUMBER | ^\d+ |
| EQUIVALENT | ^== |
| PLUSEQUAL | ^+= |
| SUBEQUAL | ^-= |
| MULTEQUAL | ^*= |
| DIVEQUAL | ^/= |
| INVERT | ^=! |
| EQUAL | ^= |
| NOTEQUIVALENT | ^!= |
| GRATERTHANOREQUAL | ^>= |
| LESSTHANOREQUAL | ^<= |
| GRATERTHAN | ^> |
| LESSTHAN | ^< |
| ADD | ^+ |
| SUB | ^- |
| MULT | ^* |
| DIV | ^/ |
| MOD | ^% |
| AND | ^& |
| OR | ^| |
| NOT | ^! |
| LEFTBRAKET | ^} |
| RIGHTBRAKET | ^{ |
| OPENPARANTHESIS | ^( |
| CLOSINGPARANTHESIS | ^) |
| OPENSQUAREBRACKET | ^[ |
| CLOSESQUAREBRACKET | ^] |
| SEMICOLON | ^; |
| NEWLINE | ^\n |
| SPACE | \s |
| COMMA | ^, |
| DOT | ^. |