discount: preserve tabs in code blocks

[ant-222]

Can you please add an option to discount that will cause it to preserve tabs in code blocks instead of replacing them with spaces? It will help people to copy-paste code from HTML into their IDE's (and editors). I for one am among those who indent with tabs but align with spaces.

[Orc]

I'm afraid that would pretty seriously break compatability with markdown, and it would certainly require a lot of reworking inside discount to implement it. (I am spoiled; I use vi and it tabifys automatically when I shift lines left or right. But certainly other text editors have that sort of functionality?) I'm sorry, but though I would be happy review a code patch to implement this, I'm gonna have to decline doing the implementation myself.

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-jessica l. parsons

On Apr 13, 2026, at 9:43 AM, Anton Shepelev ***@***.***> wrote: ant-222 created an issue (Orc/discount#306) <#306> Can you please add an option to discount that will cause it to preserve tabs in code blocks instead of replacing them with spaces? It will help people to copy-paste code from HTML into their IDE's (and editors). I for one am among those who indent with tabs but align with spaces. — Reply to this email directly, view it on GitHub <#306>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAAE5AWU62JOSJCDAVRVPVT4VUKLTAVCNFSM6AAAAACXXUH2ESVHI2DSMVQWIX3LMV43ASLTON2WKOZUGI2TMNBXGE4TONA>. You are receiving this because you are subscribed to this thread.

[ant-222]

@Orc

I'm afraid that would pretty seriously break compatability with markdown,

On the contrary—Markdown is actually designed to support combined alignment (example), whereas a quiet convertion of tabs to spaces violates the standard. The standard says:

internal tabs are passed through as literal tabs, not expanded to spaces

You continue:

and it would certainly require a lot of reworking inside discount
to implement it.

I'd say that such accurate tracking of indent state and structure is a task of medium difficulty, especially because a reference implementation can be consulted.

(I am spoiled; I use vi and it tabifys automatically when I shift lines left or right. But certainly other text editors have that sort of functionality?)

Yes, it does, if set up accordingly. And its autoindent ruins combined indentation. Vim's copyindent amends this somewhat.

I'm sorry, but though I would be happy review a code patch to implement this, I'm gonna have to decline doing the implementation myself.

Thank you.

[Orc]

On Jun 1, 2026, at 10:01 AM, Anton Shepelev ***@***.***> wrote: ant-222 left a comment (Orc/discount#306) <#306 (comment)> I'd say that such accurate tracking of indent state and structure is a task of medium difficulty, especially becase a reference implementation can be consulted.

? The reference implementation consumes tabs, so I am doubtful. But in any case I would welcome a chance to review a patch that implements your desired functionality.

[ant-222]

@Orc

? The reference implementation consumes tabs, so I am doubtful.

Hmmm. Let us first come to a consensus about the observable facts. Do you agree that the JavaScript reference implementation a) accepts combined indents (consising of tabs and spaces) and b) preserves tabs in code blocks, as demonstrated in my example?

What exactly do you mean by consuming tabs?

But in any case I would welcome a chance to review a patch that implements your desired functionality.

I may be not able to take this in the near future, but since discount is written in C, it is within my ability.

[Orc]

The reference implementation is John Gruber's markdown.pl.

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-jessica l. parsons

On Jun 2, 2026, at 1:57 AM, Anton Shepelev ***@***.***> wrote: ant-222 left a comment (Orc/discount#306) <#306 (comment)> @Orc <https://github.com/Orc> ? The reference implementation consumes tabs, so I am doubtful. Hmmm. Let us first come to a consensus about the observable facts. Do you agree that the JavaScript reference implementation a) accepts combined indents (consising of tabs and spaces) and b) preserves tabs in code blocks, as demonstrated in my example <https://spec.commonmark.org/dingus/?text=%3E%20This%20a%20block%20quiote%20with%20a%20nested%20code%20block.%0A%3E%0A%3E%20%60%60%60%0A%3E%20int%20sum(int%20a%2C%20int%20b)%0A%3E%20%7B%0A%3E%20%09return%20a%20%2B%20b%3B%0A%3E%20%7D%0A%3E%20%60%60%60%0A%0A%0A*%20This%20is%20a%20list%20with%20a%20code%20block%20in%20the%20next%20item.%0A%0A*%20%60%60%60%0A%20%20int%20sum(int%20a%2C%20int%20b)%0A%20%20%7B%0A%20%20%09return%20a%20%2B%20b%3B%0A%20%20%7D%0A%20%20%60%60%60>? What exactly do you mean by consuming tabs? But in any case I would welcome a chance to review a patch that implements your desired functionality. I may be not able to take this in the near future, but since discount is written in C, it is within my ability. — Reply to this email directly, view it on GitHub <#306?email_source=notifications&email_token=AAAE5ATCBJBM67MYPOOYLK3452JIDA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTINRQGA3DIMBTGAYKM4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJLDGN5XXIZLSL5RWY2LDNM#issuecomment-4600640300>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAAE5AQSOYNT4D3FXSSAOO3452JIDAVCNFSM6AAAAACXXUH2ESVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHM2DMMBQGY2DAMZQGA>. Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS <https://github.com/notifications/mobile/ios/AAAE5AQQSDIZEUBVR46XJHT452JIDA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTINRQGA3DIMBTGAYKM4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJKTGN5XXIZLSL5UW64Y> and Android <https://github.com/notifications/mobile/android/AAAE5ATCROARC4UB2WWO6FD452JIDA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTINRQGA3DIMBTGAYKM4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJLTGN5XXIZLSL5QW4ZDSN5UWI>. Download it today! You are receiving this because you were mentioned.