Suggestions on formatting of code

[PeterJ]

but almost always aligned.

Thanks for the sake of my OCD, it must be aligned always!

[ketmar]

but almost always aligned.

Thanks for the sake of my OCD, it must be aligned always!

and it is also easier to quickly scan the code too. syntax highlighting helps too, but with aligned parts it is even easier. this habit (aligning) actually came from GENS assembler (it did it automatically for you).

[catmeows]

Basically what everybody says:
1) comment, comment, comment ...
2) align by columns
3) meaningfull labels

Code: Select all

dutyModification
	ld a, (ix + DUTY)		
	ld c, (ix + DUTYDELTA)
	add a, c			;add duty change to duty
	bit 7, c			;is delta negative ?
        jr nz, negDutyDelta
	ld b, (ix + DUTYMAX)		;compare with max duty
	cp b
	jr c, noDutyChange		;will not change duty delta sign
dutyChange
	ld a, c				;negate duty delta			
	neg 
	ld c, a
	ld a, b				;and set min/max limit as duty
	ld (ix + DUTYDELTA), c		;store new delta
noDutyChange
	ld (ix + DUTY), a		;store new duty
	ret
negDutyDelta
	ld b, (ix + DUTYMIN)		;compare with min duty
	cp b				
	jr nc, noDutyChange		;will not change duty delta sign
	jr dutyChange

noteModification
	ld a, (ix + NOTELEN)		;decrease note length
	dec a
	ld (ix + NOTELEN), a
noteNoLastTick
	ld a, (ix + ARPFLAG)		;is appergio enabled ?
	or a
	jr z, noteNoArp			;no
	ld a, (tickCounter)		;if appergio enabled
	and 1				;every second tick play tone one octave higher
	jr z, noteNoArp
	ld a, 12			;octave plus
noteNoArp
	add a, (ix + BASENOTE)		;add nothing or octave to base note
	call getNoteFreq		;get note frequency
	ld a, (ix + VIBRATOFLAG)
	or a
	jr z, noteNoVibrato		;no vibrato		
	ld de, 47			;1 + 11*2 = 23
	add hl, de			;move note 
	ld a, (hl)
	inc hl
	ld h, (hl)			;get frequency for note+1
	ld l, a
	or a
	sbc hl, bc			;difference between notes to HL	
	ld a, (ix + VIBRATODEPTH)		
vibratoDepth	
	srl h
	rr l
	dec a
	jr nz, vibratoDepth		; delta of frequency / ( 2^vibratoDepth)
	ld a, (vibratoCounter)		; now multiply vibrato depth by vibracounter
	or a
	jr z, noteNoVibrato		;level 0
	ld d, h				
	ld e, l				
	bit 1, a				
	jr nc, vibratoBit1		
	add hl, hl			
vibratoBit1
	rra
	jr c, vibratoBit0
	add hl, de
vibratoBit0
	add hl, bc			; add vibrato to base note frequence
	ld c, l
	ld b, h
noteNoVibrato	
	ld a, (ix + PORTAMENTOFLAG)
	or a
	jr z, noteNoPortamento		;no portamento 
	ld e, (ix + PORTAMENTOLO)
	ld d, (ix + PORTAMENTOHI)
	ld l, e
	ld h, d
	add hl, bc			;add portamento to frequency
	ld c, l				;store final frequency
	ld b, h
	ld l, (ix + PORTAMENTODELTALO)	
	ld h, (ix + PORTAMENTODELTAHI)
	add hl, de			;update portamento
	bit 7, (ix + PORTAMENTODELTAHI)	;is delta negative ?
	jr z, notePortamentoChange
	ccf
notePortamentoChange
	jr nc, notePortamentoContinue
	xor a				;switch portamento off
	ld (ix + PORTAMENTOFLAG), a
notePortamentoContinue
	ld (ix + PORTAMENTODELTALO), l	;store portamento delta
	ld (ix + PORTAMENTODELTAHI), h
noteNoPortamento
	;BC is final frequency
	ld a, (ix + RELEASEFLAG)
	or a
	ret z				;if not release then exit
	ld a, (ix + NOTELEN)
	or a
	ret nz				;is last tick ?
	ld bc, 0			;erase frequency for the very last tick
	ret

[Ralf]

I do both ways.
When coding for Spectrum I never use automatic formatting, I always do it my own, (sometimes inconsistent ) way.

When I have short labels I May do

Code: Select all

DS1 LD A,(HL)
    INC HL
DS2 LD B,(HL)

But what if I have a label like CopyEnemyGraphicDataToBuffer ?
And yes, I use this kind of labels too, we may have this comfort, it's 2020.

Imagine typing these all spaces/tabs with each instruction:

Code: Select all

CopyEnemyGraphicDataToBuffer LD A,(HL)
                             INC HL
                             LD B,(HL)

So in case of long labels I prefer

Code: Select all

CopyEnemyGraphicDataToBuffer 
 LD A,(HL)
 INC HL
CopyEnemyGraphicDataToBuffer 2
 LD B,(HL)

[Ralf]

I would just strongly advise keeping komments aligned:

LAZY AND BAD:

Code: Select all

LD C,D ;comment1
LD A,(PlayerStatus) ;comment2

GOOD:

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LD C,D              ;comment1
LD A,(PlayerStatus) ;comment2

[PeterJ]

I know it doesn't make a jot of difference to the assembler, but it's interesting how some of you are using uppercase, and others lowercase.... Just be consistent I suppose is the answer.

[Seven.FFF]

Again it may make a difference, as some assemblers will treat a reserved word as an opcode if it’s entirely upper or lower case, but allow the same reserved word as a label if it is in mixed case.

Also some editors and IDEs detect the intent of the current line, and will auto-indent the next line by the same amount when you hit enter, so having a large indent optimised for long labels doesn’t cause more effort.

[Ralf]

I know it doesn't make a jot of difference to the assembler, but it's interesting how some of you are using uppercase, and others lowercase.... Just be consistent I suppose is the answer.

It's called S T Y L E

[Stefan]

IN THE OLD DAYS UPPERCASE WAS USEFUL SINCE LOWERCASE LETTERS COULD BE HARDER TO READ, THESE DAYS, UPPERCASE IS JUST CONSIDERED SHOUTING!!!!

(yes I grew up from uppercase to lowercase).

[kolbeck]

https://youtu.be/SsoOG6ZeyUI

[PeterJ]

Excellent [mention]kolbeck[/mention]

I haven't laughed so much in months.

[andydansby]

My preference has been for camelCase, just easier on my eyes.

[kolbeck]

Excellent @kolbeck

I haven't laughed so much in months.

One of my favorite episodes

[ketmar]

as for me, i just can't remember how to type those big letters. have to copy-paste them from a premade text file.

[Ast A. Moore]

Okay, the video was brilliant!

Now, to address some of Peter’s concerns. Many text editors that are tailored to programmers will do a few things for you to make your life easier. For one, they provide syntax highlighting (not the editors themselves, but their extensions). Take a look at the one I wrote for TextMate:



Second, TextMate (and many others) will automatically tabulate your code. Once you’ve started a line with a tab, when you press Return, the next line will be automatically tabulated to line up with the line before. I don’t know what text editor you use, but I know that the reason I switched to TextMate from TextEdit (the macOS version of Notepad) and wrote the Z80 syntax highlighter was precisely because of these two problems: code readability and tabulation.

[PeterJ]

Thank you [mention]Ast A. Moore[/mention],

I currently just use notepad, but use VS Code for other stuff, so will see if that has some of the functionality you mention. VS Code is good because it runs on both Windows and Linux.

[flatduckrecords]

I’ve found that re-indenting unfamiliar code is a useful aid to understanding it. [mention]Alessandro[/mention] shared a really useful text-scrolling routine a while ago, and walking through it a few lines or a block at a time helped me to understand it better. Nothing wrong with the original formatting, I should say! (I’m very new to assembly so still developing my own taste/style anyway) but I found the process of visually marking each line in way that made sense to me (i.e. to distinguish what’s a label, from an opcode, from a reference to a label, etc.) to be a useful exercise.

When writing my own code I use VS Code which auto-indents each new line, as [mention]chilledgamer[/mention] mentioned. Being able to block-edit chunks of code is really helpful too. Plugins are available to help with syntax-highlighting (which I find helpful) and auto-suggest (but that just seems to get in the way as often as it helps!)

[ketmar]

I’ve found that re-indenting unfamiliar code is a useful aid to understanding it.

same here! i'm using this method to understand other people's code for decades.

[Turtle_Quality]

So no-one indenting for loops, conditional code etc ???

Just throwing that in there as that was the norm with VBA code where I worked a few years ago, and kind of helped with visibility. Obviously it was not practical on the Spectrum but now everyone editing code on PCs not a 32 column Spectrum

[ketmar]

So no-one indenting for loops, conditional code etc ???

it is not even always possible, considering that jumps can create a fine web. it is much easier (and cleaner, i believe) to split the code to "logical blocks" with empty lines.

[utz]

So no-one indenting for loops, conditional code etc ???

it is not even always possible, considering that jumps can create a fine web. it is much easier (and cleaner, i believe) to split the code to "logical blocks" with empty lines.

Exactly, it's not always possible/useful to apply best formatting practises from higher level languages to assembly.

I have a habit of always putting an empty line after jp/jr/call/ret. I also agree with ketmar that blank lines are a good way of separating logical blocks of code. Multiple lines and/or decorated comments for larger units, aka

Code: Select all

; --------------------------------------
; A new section starts here
; --------------------------------------

Also I generally don't put labels on the same line as code, but that's more down to personal preference, I guess.

[kolbeck]

Thank you @Ast A. Moore,

I currently just use notepad, but use VS Code for other stuff, so will see if that has some of the functionality you mention. VS Code is good because it runs on both Windows and Linux.

I use VS code with a z80 formatter/highlighter found on marketplace- works great on Mac as well.

[Cosmium]

I know it doesn't make a jot of difference to the assembler, but it's interesting how some of you are using uppercase, and others lowercase.... Just be consistent I suppose is the answer.

I always use uppercase for the Z80 instructions. Just seems to make them immediately stand out against the rest of the test. That and it's a habit from the past!

[Ast A. Moore]

I know it doesn't make a jot of difference to the assembler, but it's interesting how some of you are using uppercase, and others lowercase.... Just be consistent I suppose is the answer.

To me, lowercasing the instructions has always looked neater. Not as SCREAMY AND SHOUTY as using all uppercase. Oh, and it’s too much extra work to hold down the Shift key.

[Einar Saukas]

To me, lowercasing the instructions has always looked neater. Not as SCREAMY AND SHOUTY as using all uppercase. Oh, and it’s too much extra work to hold down the Shift key.

Next time try using CAPS LOCK


EDIT: Jokes aside, I personally think lowercase mnemonics are more legible too.