🔒 Help making a programming language!

[lime hawk]

@pearl saffron

Python help channel opened

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[pearl saffron]

hey everybody
ive been trying to make a langguage in python recently
but im not very good at it
and i cant figure out how oto make if conditions and code blocks

and functions and inputs and stuff like taht

https://paste.pythondiscord.com/L3UQ

that link is the pastebin for the code so far

[feral sky]

Let's start with if statements. Do you already have a syntax in mind?

[pearl saffron]

exacly like c

c++ i mean

[feral sky]

So like this? ```
if (condition) {
code
}

[pearl saffron]

Yup!

[feral sky]

guess what, C and C++ have the same if syntax :p

[pearl saffron]

oh yeah

sry brain fart

[feral sky]

Have you tried writing code which can parse it?

[pearl saffron]

kindof

but

it didnt ork out well

[feral sky]

Can you send what you tried?

[pearl saffron]

i dont have it sadly

maybe

no sry wait i cnat find it

[feral sky]

That's fine, we can make it from the ground up

[pearl saffron]

alr!

[feral sky]

Actually, you would need to add curly braces to the tokenizer first

[pearl saffron]

hm

so should i add it at the bottom

[feral sky]

Anywhere above MISMATCH is fine

[pearl saffron]

alr

[feral sky]

but I would put it before COMMA with the other paired symbols

[pearl saffron]

just did it

ima update the paste bin

https://paste.pythondiscord.com/HEJA

new link

[feral sky]

looks alright

(to be pedantic, LEFT_BRACE/RIGHT_BRACE would be more consistent but it doesn't really matter anyway)

[pearl saffron]

lol ok

[feral sky]

Alright, so the if statement is a statement

and you know a statement is one when it starts with if

[pearl saffron]

ok

so do i add an if token?

[feral sky]

Since you're using IDENTIFIER for print anyway you can do the same for if

[pearl saffron]

ddo i change the token[] array to token[2] for if like i did token[1] for print

[feral sky]

why not try run it and find out?

[pearl saffron]

k

hey is it ok if we can contiue this in dms?

[feral sky]

any particular reason why?

I usually don't do DMs

[pearl saffron]

i was wondering if you wanted to vc, it would make the proccess a whole lot easier

[feral sky]

ah, unfortunately I'm already in a different vc

[pearl saffron]

ah ok

hey

is this good?

def parse_statement(self):
token = self.current_token()
if token[0] == 'IDENTIFIER':
if self.peek_token() and self.peek_token()[0] == 'ASSIGN':
return self.parse_assignment()
elif token[1] == 'print':
self.eat('IDENTIFIER')
return ('PRINT', self.parse_expression())
elif token[2] == 'if':
self.eat('IDENTIFIER')
return ('IF', self.parse_expression())
raise SyntaxError(f"Unexpected token: {token}")

[lime hawk]

Hey @pearl saffron!

It looks like you're trying to paste code into this channel.

Discord has support for Markdown, which allows you to post code with full syntax highlighting. Please use these whenever you paste code, as this helps improve the legibility and makes it easier for us to help you.

To do this, use the following method:
```py
print('Hello, world!')
```

This will result in the following:

print('Hello, world!')```
You can **edit your original message** to correct your code block.

[pearl saffron]

        token = self.current_token()
        if token[0] == 'IDENTIFIER':
            if self.peek_token() and self.peek_token()[0] == 'ASSIGN':
                return self.parse_assignment()
            elif token[1] == 'print':
                self.eat('IDENTIFIER')
                return ('PRINT', self.parse_expression())
        elif token[2] == 'if':
                self.eat('IDENTIFIER')
                return ('IF', self.parse_expression())
        raise SyntaxError(f"Unexpected token: {token}")```

[feral sky]

Not quite, but it's close

[pearl saffron]

what do i do from here?

[compact rain]

also things like that could use an enumeration just so you don't have to remember how you spell all the tokens

[pearl saffron]

im not that great at python, sry lol

[feral sky]

Remember, we're trying to look for if, which would be ('IDENTIFIER', 'if') when tokenized

so ||the elif should be indented inside if token[0] == 'IDENTIFIER':|| and ||the condition should use token[1]||

[compact rain]

unless the lexer parses if as a unique token

[feral sky]

(which it doesn't, for now)

[compact rain]

then i guess that, yeah

[feral sky]

^ here's OP's code for reference

[compact rain]

ah, it doesn't load for me

a

updated one

[feral sky]

as in the message?

[pearl saffron]

done

changed it to token[1]

the elif is already indented

[compact rain]

i was initially looking at their first link 😅

[feral sky]

alright; now let's break down an if statement to see how we can parse it

can you break it down into specific tokens/expressions/statements?

[pearl saffron]

well

first we have the keyword, thats "if"

he have whitespce but that gets ignored

then we have brackets with arguments inside of it

an opening bracket

and then either integers or variables for the first argument

and strings

OH

[compact rain]

to be more exact - there should be an expression inside

[feral sky]

arguments?

[pearl saffron]

we need == <= etc

[pearl saffron]

i ment the condition lol

we need to make tokens for == <= etc

[feral sky]

Yes, we might want to add conditional operators first

[pearl saffron]

okok

ima do it

ima add it after the divide opperator

[pearl saffron]

yo

for eq is this correct

('EQ', r'=='),

[feral sky]

try it and we'll see ;)

[pearl saffron]

alr

ima add the rest

[pearl saffron]

        ('LESST', r'<'),
        ('MORET', r'>'),
        ('LQ', r'<='),
        ('GQ', r'>='),
        ('NOTQ', r'!='),
        ('AND', r'&&'),```

[feral sky]

LGTM, does it work?

[pearl saffron]

idk we havent done anything with em yet

but i think it should

[feral sky]

perhaps test it with just tokenization

[pearl saffron]

code = """
x = [1, 2, 3]
y = ["hello", "world"]
z = x + [4, 5]
a = y + ["!"]
print z
print a
augh = 3
alala = "huhuh"
print x[2]
print y[0]
print ((x[1] + x[2]) * 3) * augh
print "hahah " + alala

""" : ERROR!
Traceback (most recent call last):
File "<main.py>", line 208, in <module>
File "<main.py>", line 183, in run_minilang
File "<main.py>", line 69, in parse
File "<main.py>", line 80, in parse_statement
SyntaxError: Unexpected token: ('ASSIGN', '=')

[lime hawk]

Hey @pearl saffron!

It looks like you are trying to paste code into this channel.

You seem to be using the wrong symbols to indicate where the code block should start. The correct symbols would be ```, not """.

Here is an example of how it should look:
```
Hello, world!
```

This will result in the following:

Hello, world!```
You can **edit your original message** to correct your code block.

[pearl saffron]

i just typed == in the last line of the custom lang

and i got this error

[feral sky]

mhm, is that what you expected?

[pearl saffron]

no

[feral sky]

why do you think that might be?

[compact rain]

take a look at the traceback

  File "<main.py>", line 208, in <module>
  File "<main.py>", line 183, in run_minilang
  File "<main.py>", line 69, in parse
  File "<main.py>", line 80, in parse_statement
                    ^^^^^^^     ^^^^^^^^^^^^^^^

and there you'll be able to see why it gave an error

[pearl saffron]

hmm idk

maybe cause it can only take in 1 char

or maybe i havent made any references anywhere in the code

ima try adding a return statemment if detectedin parse_factor()

[feral sky]

but it can take identifiers which are multiple characters

[pearl saffron]

yeah ye just noticed

[feral sky]

I would test with just the tokenizer so the parser doesn't get in the way

[pearl saffron]

kk

[pearl saffron]

i did this but got same issue: def parse_statement(self):
token = self.current_token()
if token[0] == 'IDENTIFIER':
if self.peek_token() and self.peek_token()[0] == 'ASSIGN':
return self.parse_assignment()
elif token[1] == 'print':
self.eat('IDENTIFIER')
return ('PRINT', self.parse_expression())
if token[0] == 'EQ':
self.eat('EQ')
raise SyntaxError(f"Unexpected token: {token}")

again im sorry for takign up alot of ur time

im not rlly good at python thtat much

i know just enough

[feral sky]

no worries, we were all beginners at one point

[feral sky]

Start from the simplest case, with just tokenization: ```py
code = "=="
print(tokenize(code))

[pearl saffron]

this is the custom lang code

code = """

"""

and this is the output

[('NEWLINE', '\n'), ('ASSIGN', '='), ('ASSIGN', '='), ('NEWLINE', '\n')]
ERROR!
Traceback (most recent call last):
File "<main.py>", line 197, in <module>
File "<main.py>", line 183, in run_minilang
File "<main.py>", line 69, in parse
File "<main.py>", line 80, in parse_statement
SyntaxError: Unexpected token: ('ASSIGN', '=')

[feral sky]

yup, so the == is being parsed as 2 =s

[pearl saffron]

yes...

maybe we should try something like this

like if it detects another = after one =

it will do ==

idk

actually

[feral sky]

I would consider the ordering of the tokens

[pearl saffron]

actually, could it be that we didnt add any parser code for it?

[pearl saffron]

hmm

ima try putting it above

u were right

[('NEWLINE', '\n'), ('EQ', '=='), ('NEWLINE', '\n')]
ERROR!
Traceback (most recent call last):
File "<main.py>", line 198, in <module>
File "<main.py>", line 184, in run_minilang
File "<main.py>", line 70, in parse
File "<main.py>", line 81, in parse_statement
SyntaxError: Unexpected token: ('EQ', '==')

[feral sky]

Essentially, higher rules get checked first so any = would always be consumed by ASSIGN before it reaches EQ

[pearl saffron]

alr ima put the rest above it

im also put the lesst and moret lower

ok

so what now?

[feral sky]

parsing comparisons!

[pearl saffron]

yo wait igtg now

sry in a rush

[compact rain]

making something like print 1 == 1 work

[pearl saffron]

talk to u after 1 hr

see ya

sry botutbis again

basketball class

bye!

[feral sky]

no problem, you can ping me later when you come back

this thread will probably be closed by then so feel free to open another one

[lime hawk]

Python help channel closed

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