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{{chem2|A_{''x''}B_{1−''x''}}} currently produces "A_xB_1-x" with the minus sign (−) in the subscript replaced by a hyphen (-), in violation of

I'm not familiar with this module, but the following lines of code might be relevant. Perhaps someone knows better? — Martin (MSGJ · talk) 17:35, 27 February 2023 (UTC)[reply]

• 277: formula = formula .. su(x:match("[+-]"):gsub("-", "−"), x:match("%d+"), "");
• 288: if parameter == "s" then formula = formula .. "−" -- single bond
• 294: elseif parameter == "-" then formula = formula .. "-" -- -

debugging & tests

see /testcases at § subscript hyphen (Feb 2023)

• More research:

Test string to be (rule: when final-} in formula input, end pipe }|}} is required):

(A) {{chem2|A_{''x''}H_{1-''x''}|}} → A_xH_1−x

Characters involved:

(H) U+002D - HYPHEN-MINUS → A_xH_1−x

(M) U+2212 − MINUS SIGN (−) → A_xM_1−x

re MSGJ: by reading the code, none of the lines 277 (good replacement), 288 (good replacement), 294 (hyphen only) seem to make the wrong replacement.

-DePiep (talk) 19:02, 27 February 2023 (UTC)[reply]

code review:

• L239 (current live): if not x then x = f:match('^\^{[^}]*}', i); t = T_CARET; end -- ^{...}

^\^{[^}]*} ? expected ^^{[^}]*} (Lua pattern not regex; module preview reports Error: [239:42] invalid escape sequence near '\^'. (Errors from this, missed? hidden?) edited in sandboxDePiep (talk) 19:57, 27 February 2023 (UTC)[reply]

• test code to be:

{{chem2|1=A^{1-''y''}B_{1-''x''}H(2-)}}

Three minus/hyphen signs input, expected result: all three Minus (M). Current live test:

Live M>−<: A^1−yB_1−xM²⁻

returns H, H, M. sup/sub issue. -DePiep (talk) 20:43, 27 February 2023 (UTC)[reply]

Bug report

• See /testcases at § subscript hyphen (Feb 2023). module:Chem2, current live code.

(H) U+002D - HYPHEN-MINUS

(M) U+2212 − MINUS SIGN (&minus;)

From original report (OP); B2-B (demo/test inline) and (4-) (charge) added as extra testcases (situations 1–4 now).

In the tests here, B2-B is added and is not targeted (no changes claimed nor expected; ignored in conclsions)

{{chem2|1=HA^{''1-x''}B2-B_{3-''x''}(4-)}}

{{chem2|1=HA^{1-x}B2-B_{3-x}(4-)}}

in H>-<: HA^1−xB−2B_3−x⁴⁻ -- N MINUS expected

in M>−<: MA^1−xB−2B_3−x⁴⁻ -- N MINUS expected

(A) Original complaint

MINUS (−) not kept when in (topically correct) sub/supscripted formula is entered; shows hyphen (-) instead.

Cause: {{Chem2}} early replaces NDASH and MINUS with HYPHEN, to be treatred similar (see code L250, 251).

When as charge, the hyphen is changed into MINUS all right, but no such replacement in the supsubscripts.

Proposed solution: in T_CARET and T_UNDERSCORE change any hyphen (from early replacement) into MINUS [1].

live, in:H>-<: HA^1−xB−2B_3−x⁴⁻

/sbx, in:H>-<: HA^1−xB−2B_3−x⁴⁻

live, in:M>−<: MA^1−xB−2B_3−x⁴⁻

/sbx, in:M>−<: MA^1−xB−2B_3−x⁴⁻

Showing: current live version returns HYPHEN in subsuptexts; correct MINUS inline and in the "(2-)" charge). All irrespective of input character.

(B) Handling of HTML entities (&minus;)

When entering like − (for character MINUS), it is not handled as the character.

Incidentally, this preserves the MINUS character as asked for in the OP (undocumented 'solution', hack).

However, not documented and would give different results between input − vs. −. Also, other codes entries could be affected.

Proposed solution: add early decoding mw.text.decode() [2].

• Entering HTML Entity −

live, in:>&minus;<: EA^1−xB−2B_3−x⁴⁻ -- incidentally, returns as expected

/sbx, in:>&minus;<: EA^1−xB−2B_3−x⁴⁻

Entering β

live, in:>&beta;<: EA^1βxB₂βB_3βx(₄β) -- as expected :/sbx, in:>&beta;<: EA^1βxB₂βB_3βx(₄β) -- same result (returns decoded &beta; to UA: decoded later)

(C) Bad code

L239: if not x then x = f:match('^\^{[^}]*}', i); t = T_CARET; end   -- ^{...}

Parser gives error: '^\^{[^}]*}' has incorrect "\" (note: expected is Lua pattern not Regex). Saves with error (-warning).

No error effects (in pages) known, nor seen in testpage.

From Lua documentation mw:Lua manual: "At other positions, '^' and '$' have no special meaning and represent themselves". That is: the second caret should represent the input character (to indicate superscript).

Proposed solution: Remove the slash: [3]. No effects in tests seen.

Testcases: see superscripts (CARET input) throughout.

(D) Escape codes limitations

The /documentation mentions \s, \- for input "single bond" (topical term) and "hyphen" when used in line. However, they don't work as expected when in sup/subscripted text (as in OP).

Proposed solution: the escape codes are not developed to function more widely. Instead, documentation to be improved (mention limitations).

• From doc: use \s, \- slashed escape code (note: "B2-B" as expected)

live, in:>\s<: SsA^1\sxB₂−B_3\sx(₄−)

/sbx, in:>\s<: SsA^1\sxB₂−B_3\sx(₄−)

live, in:>\-<: ShA^1\−B₂-B_3\−x(₄-)

/sbx, in:>\-<: ShA^1\−B₂-B_3\−x(₄-)

-DePiep (talk) 00:06, 28 February 2023 (UTC)[reply]

(T) more tests: bare hyphen: input without no preceding number etc in text element (eg, charge "(-)"):

HA^−x−B_−x⁻

HA^−x−B_−x⁻

MA^−x−B_−x⁻

MA^−x−B_−x⁻

EA^−x−B_−x⁻ -- &minus;

EA^−x−B_−x⁻

Adjustmensts, refining testcases, spell uc MINUS etc, create 4 numberred testsituations DePiep 05:41, 28 February 2023

For more bare "-" input tests (not "2-" &tc;), see /testcases (UTC), -DePiep (talk) 06:36, 28 February 2023 (UTC)[reply]

Proposal (code edit)

From the Report above, I propose to oconsider: edit all code from module:Chem2/sandbox into module:Chem2 (diff).

Note: the (B) may change behaviour (instances relying on undocumented effects). Conservation action needed? OTOH, when entering &minus;, what else should be expected than MINUS?

Also, I'd like to have chemicist eyes taking a look.

More tests at the Template:Chem2/testcases.

-DePiep (talk) 00:06, 28 February 2023 (UTC)[reply]

@Christian75, Mikhail Ryazanov, and MSGJ: demos and tests stable & ok now, please take a look. -DePiep (talk) 06:41, 28 February 2023 (UTC)[reply]

Thanks, DePiep! As far as I can tell, the new code works definitely better, at least in terms of indices. I would say that minus signs in indices (upper and lower) are certainly much more common than hyphens, so the general idea to replace input "-" (ASCII hyphen-minus) with output "−" (Unicode minus) is quite reasonable. I suspect that there might be legitimate cases for hyphens in indices when something text-like is used (similar to "_{(g)}", but I can't provide a specific example), so making the escape sequence "\-" producing output "-" in all contexts would be nice. — Mikhail Ryazanov (talk) 22:14, 28 February 2023 (UTC)[reply]

@Christian75 and MSGJ:, any remarks? -DePiep (talk) 17:17, 2 March 2023 (UTC)[reply]

If you have only a minute to spare, consider checking this essence: in the testases, are the minus-signs and the hyphens in the right places now? DePiep (talk) 18:54, 2 March 2023 (UTC)[reply]

 Done * Pppery * _{it has begun...} 22:10, 4 March 2023 (UTC)[reply]

I propose to add these parameters checks:

(1) Module:Check for unknown parameters

Checks regular parameter usage, also for unnamed parameters.

|2= can be present, see (2) below, but must be empty.

(2) Check for unbalanced {...} brackets

When entering {{Chem2}} like {{chem2|A_{x}H_{1-x}}}, the final }-brackets are technically mixed up: closing bracket {..} of input and end of template brackets }}.

result: {{chem2|A_{x}H_{1-x}}} → A_xH_{−1x} N

(B) is to check for such bad parameter effect. The page will be categorised.

• Solutions (for the editor, /documentation):

add empty pipe: {{chem2|..{..}|}} (empty parameter #2);

add parameters numbers 1 and 2 (empty): {{chem2|1=..{..}}};

add a space: {{chem2|..{..} }}.

• Both checks will give a preview warning.

Example, by /sandbox2:

{{chem2/sandbox2|foo=H2O|1=A_{x}H_{1-x}}} → A_xH_{−1x}

This warning does not fix or alter the error.

Chem2 code used: Module:Chem2 (=current live code)

Tracking category is Category:Pages using Chem2 with parameter issues (0) (new, one for all parameter checks).

Test code is in {{Chem2/sandbox2}}.

Testcases in Template:Chem2/testcases § Proposal: add parameter checks.

-DePiep (talk) 08:50, 28 February 2023; -DePiep (talk) 13:48, 6 March 2023 (UTC)[reply]

demo

Use Preview: All tests are with {{chem2/sandbox2}} (/sandbox2), and the live module.

Check 1, unknown parameter (preview)

A. {{chem2|1=Fe3S2(CO)9|foo=hydro}} → Fe₃S₂(CO)₉

Check 2: threee end-brackets = ambiguous & wrong

B. {{chem2|CH4_{(g)}}} → CH₄_{(g)} (err)

C. {{chem2|CH4_{(g)} |}} → CH_4(g) (ok)

Check 3: extra pipe is used, but |2= has input

D. {{chem2|CH4_{(g)}|2=barefoo}} → CH_4(g) -- (|2=barfoo not correct)

E. {{chem2|CH4_{(g)|2=barefoo}} → CH₄_{(g) -- unbalanced brackets in input string

F. {{chem2|C{1}4_{(g)}} → C{₁}₄_{(g) -- unbalanced brackets in input

G. {{chem2|C1}4_(g)}} → C₁}₄_(g) -- unbalanced closing brackets in input

-DePiep (talk) 16:10, 6 March 2023 (UTC)[reply]

Template-protected edit request on 18 March 2023

This edit request has been answered. Set the |answered= or |ans= parameter to no to reactivate your request.

• Please replace all code from {{Chem2/sandbox2}} into {{Chem2}} (compare )

Notes: only {{Chem2}} template code, module not changed; and ../sandbox2 is used (development reasons).

Changes: (1) parameters check by checkfup,

(2) extra check for end-}-bracket misreading with template-closing brackets }} (See Template:Chem2 § end-bracket issue)

Error category: Category:Pages using Chem2 with parameter issues (0).

Talk/tests/demo: see #Proposal: add parameter checks (preview warnings).

New code only warns/categorises. No changes to template output are made. DePiep (talk) 16:10, 18 March 2023 (UTC)[reply]

 Done — Martin (MSGJ · talk) 14:12, 20 March 2023 (UTC)[reply]

Template-protected edit request on 20 March 2023

This edit request has been answered. Set the |answered= or |ans= parameter to no to reactivate your request.

Please replace all code from {{Chem2}} with {{Chem2/sandbox}} (diff).

Change: bugfix. Adds |auto, link= to whitelist for check f.u.p. Was mistakingly missed in edit § Template-protected edit request on 18 March 2023 (by me). Causing Category:Pages using Chem2 with parameter issues (0) to fill. DePiep (talk) 17:05, 20 March 2023 (UTC)[reply]

 Completed.

ed. ^{put'er there} 11:18, 21 March 2023 (UTC)[reply

]

Thanks. Tracking category is populated usefully now. DePiep (talk) 11:46, 21 March 2023 (UTC)[reply]

Yes, I saw that, my pleasure! Paine  12:00, 21 March 2023 (UTC)[reply]