Top Down Parsers - Recursive Descent Parsers

Compiler Design: Top Down Parsers - Recursive Descent Parsers
Topics discussed:
1. Top-down Parsers.
2. Example of Recursive Descent Parser.
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Music:
Axol x Alex Skrindo - You [NCS Release]
#CompilerDesignByNeso #CompilerDesign #Parsers

[@muneeburrehman4690]

Got me way too excited during the dry run! Amazing teaching skills, thanks!

[@robinhood9617]

please upload the rest of the series fast having test tomorrow

[@cggrandmaster7957]

This was amazing teaching, a great lesson, fascinating. Thank you.

[@kleptosensei2419]

🎯 Key Takeaways for quick navigation:
00:33 🔄 Top-down parsers can be categorized into two types: with backtracking (using brute force algorithms) and without backtracking. This session focuses on top-down parsers without backtracking.
01:16 🌲 Top-down parsers use the top-down approach to generate parse trees, employing leftmost derivation. Context-free grammars for these parsers should be free of left recursion and non-determinism.
02:40 📜 Recursive Descent Parser is a top-down parser built from mutually recursive procedures or their non-recursive equivalents, where each procedure implements a non-terminal of the grammar.
04:16 🌐 Illustrated a Recursive Descent Parser example for a grammar, demonstrating how procedures for non-terminals mirror the grammar structure.
09:06 🎉 The main function initiates parsing by calling the starting non-terminal (e.g., function `e`), and successful parsing is confirmed by checking if the lookahead symbol is the dollar symbol.
Made with HARPA AI

[@gatecomputerscience1484]

Teacher is best but not consistent ♥️

[@shahshah-wi9kk]

😂🤣😅true

[@clock_control7920]

Sir please complete it as soon as possible

[@kumaravelrajan]

Thanks!

[@rishiluniya3295]

i think in main you have to take one character i.e.look_ahead=getchar() before E(); for the code to actually work

[@oonmm]

DIDN'T WE!?
Yes sir, we did! Great video!

[@axonis2306]

The look_ahead check in E() is wrong because if you have an empty (just $) input, it will be parsed as successful. That would be wrong because input must start with an i. The correct E() is:
{
match('i');
E'();
}

[@prestoX]

This is probably the most spectacular video on recursive decent parser on youtube !

[@shastiraj3904]

I have a question that Initially how will the look_aheak is assigned.

[@satishsgm0157]

Standard teaching!! 😇😇

[@TechnoSan09]

really fantastic explanation
but a doubt,
look_ahead == , the `==` operator does the same job of match()
then why do we need to put match() function/procedure again

[@dileepreddy704]

best explaination ever your way of teaching is simply brilliant and easy understanding👌

[@MOSHIURRAHMANVLOG]

previous chapter link please!

[@yathishkumary1867]

Thank you for uploading the video. Its really helpful for us in gate preparation. I am willing to get neso fuel for the compiler design videos. Kindly keep uploading the videos on compiler design series. Thank you very much♥♥

[@saraalsayed8241]

Thank you for the amazing explanations in all these videos. Please upload the rest of this course as soon as possible, very appreciated!

[@anonymousguy9263]

Please upload this series fast..

[@continnum_radhe-radhe]

❤❤❤

[@pawankalyanfan9328]

excellent sir wow
explanation

[@michaelmiller7892]

Stop yelling at me

[@smvnt3803]

Loved this video. I wish there was a video like this for the grammar of a real language! Would probably be too long but hey it'd be fun.

[@anmolvarshney6551]

Please upload rest fast

[@winnersusmita6731]

Spectacular video ... Thank you

[@andrewdunbar828]

dissent

[@gemsof279]

so we basically code the grammar

[@ellabry9730]

what coding language is used in the video

[@gunasekhar3732]

Upload ppts

[@RandomThingHappens]

amazing explanation

[@user-zj9pq5xc7x]

ambeegwuidyyyy

[@ohmyfriends123]

Don't having any errors

[@ohmyfriends123]

Please correction it sir

[@dinushachathuranga7657]

Thank you for the clear explanations❤❤

[@pantula_kartik_pk073]

Can you please clear this doubt for me?
The E'() function according to you is:
E' ()
{
if(la == '+')
{
match('+');
match('i');
E'();
}
}
But why it cannot be :
E' ()
{
if(la == '+')
{
match('+');
if(la == 'i')
{
match('i');
E'();
}
}
}
Please clarify this.

[@ksaipraneeth6524]

First code checks if the current lookahead token (la) is '+'. If it is, it matches '+', followed by 'i', and then makes a recursive call to E'(). This corresponds to the production E' -> +iE'.
after encountering '+', 'i' must immediately follow. If there's any deviation from this pattern in the input, it indicates a syntax error.
If the grammar had allowed other tokens after '+', then the second version with an additional check (if(la == 'i')) would have been appropriate for handling alternative possibilities.

[@Swapna-swaps]

Tq sir

[@jimnt8829]

why is he so loud?

[@PETERPARKER-ln3fy]

AWESOME

[@kwokhocheng-zf3fo]

😂😅😊😊
😂😅😊😊

[@alibabarahaei2229]

perfect

[@ohmyfriends123]

Please sir

[@thegodfatheram]

Thank you sir 🇮🇶

[@prethiviv.s5141]

Which language is this?

[@rajeshprajapati1851]

C language

[@findmeifucan2719]

Telugu

[@none9304]

urdu

[@samarthtandale9121]

This is such a Great series ... !!! Thanks 100%

[@techanand2193]

Ist viewer in 5 s

[@gugulothuvamshi5837]

overacting in language