Import statement does not follow identifier equality rules

[Vladar4]

The manual vaguely implies that module names should follow identifier equality rules (so, partial case-insensitivity and underscore is ignored).

A valid module name can only be a valid Nim identifier

https://nim-lang.org/docs/manual.html#modules
https://nim-lang.org/docs/manual.html#lexical-analysis-identifier-equality

But it appears that import statements treat foobar, foo_bar, or fooBar as different modules.

Example

import foobar

import foo_bar

import fooBar

# with only `foobar.nim` file present all three cases should work identically.

Current Output

Error: cannot open file: foo_bar

Expected Output

Normal compilation conforming to identifier equality.

Possible Solution

If I am mistaken about the idea that import statement should follow identifier equality rules, it would be helpful if it was reflected in the manual. Otherwise there is a bug in the import statement.

Additional Information

Original discussion: Vladar4/sdl2_nim#35 (comment)

$ nim -v
Nim Compiler Version 1.5.1 [Linux: amd64]
git hash: 3645f5fc7ae885e22cb52b9f865edf062cfb8e59

[top-master]

The foo_bar with underscore is right to be treated differently, and any said "manual vaguely implies" should be fixed instead.

But if foobar is a Nim-package, then import foobar and import fooBar being treated differently is an issue, which should be fixed, for example, forbid packages from mixing upper-case, or simply import case-insensitive.

However, if foobar is a .nim file, then Nim should import case-sensitive even if on Windows OS, to ensure that code compiles for our macOS co-workers as well.

[c-blake]

!nim c

import parseUtils   # works
import std/strUtils # fails
import seq_utils    # fails

[github-actions]

🐧 Linux bisect by @c-blake (contributor)

devel 👎 FAIL

Output

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-09-23T11:22:15
• Finished 2024-09-23T11:22:15
• Duration now

AST

stable 👎 FAIL

Output

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-09-23T11:22:18
• Finished 2024-09-23T11:22:18
• Duration now

AST

2.0.8 👎 FAIL

Output

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-09-23T11:22:18
• Finished 2024-09-23T11:22:18
• Duration now

AST

2.0.0 👎 FAIL

Output

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-09-23T11:22:21
• Finished 2024-09-23T11:22:21
• Duration now

AST

1.6.20 👎 FAIL

Output

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-09-23T11:22:23
• Finished 2024-09-23T11:22:23
• Duration now

AST

1.4.8 👎 FAIL

Output

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-09-23T11:22:25
• Finished 2024-09-23T11:22:25
• Duration now

AST

1.2.18 👎 FAIL

Output

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-09-23T11:22:27
• Finished 2024-09-23T11:22:27
• Duration now

AST

1.0.10 👎 FAIL

Output

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-09-23T11:22:29
• Finished 2024-09-23T11:22:29
• Duration now

AST

Stats

• GCC 11.4.0
• Clang 14.0.0
• NodeJS 20.4
• Created 2024-09-23T11:21:48Z
• Comments 2
• Commands nim c --run -d:nimDebug -d:nimDebugDlOpen -d:ssl -d:nimDisableCertificateValidation --forceBuild:on --colors:off --verbosity:0 --hints:off --lineTrace:off --nimcache:/home/runner/work/Nim/Nim --out:/home/runner/work/Nim/Nim/temp /home/runner/work/Nim/Nim/temp.nim

🤖 Bug found in 16 mins bisecting 8 commits at 0 commits per second

[c-blake]

!nim c

import seq_utils

Repeated but simplified just to show the non-std/-qualified import with style variation also fails on all hot-loadable test Nim versions.

[github-actions]

🐧 Linux bisect by @c-blake (contributor)

devel 👎 FAIL

Output

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-09-23T11:26:26
• Finished 2024-09-23T11:26:26
• Duration

AST

stable 👎 FAIL

Output

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-09-23T11:26:30
• Finished 2024-09-23T11:26:30
• Duration now

AST

2.0.8 👎 FAIL

Output

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-09-23T11:26:30
• Finished 2024-09-23T11:26:30
• Duration now

AST

2.0.0 👎 FAIL

Output

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-09-23T11:26:34
• Finished 2024-09-23T11:26:34
• Duration now

AST

1.6.20 👎 FAIL

Output

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-09-23T11:26:37
• Finished 2024-09-23T11:26:37
• Duration now

AST

1.4.8 👎 FAIL

Output

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-09-23T11:26:40
• Finished 2024-09-23T11:26:40
• Duration now

AST

1.2.18 👎 FAIL

Output

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-09-23T11:26:42
• Finished 2024-09-23T11:26:42
• Duration now

AST

1.0.10 👎 FAIL

Output

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-09-23T11:26:43
• Finished 2024-09-23T11:26:43
• Duration now

AST

Stats

• GCC 11.4.0
• Clang 14.0.0
• NodeJS 20.4
• Created 2024-09-23T11:25:54Z
• Comments 4
• Commands nim c --run -d:nimDebug -d:nimDebugDlOpen -d:ssl -d:nimDisableCertificateValidation --forceBuild:on --colors:off --verbosity:0 --hints:off --lineTrace:off --nimcache:/home/runner/work/Nim/Nim --out:/home/runner/work/Nim/Nim/temp /home/runner/work/Nim/Nim/temp.nim

🤖 Bug found in 20 mins bisecting 8 commits at 0 commits per second

[Araq]

Only needs to be documented, Nim first tries the name as written and then in all lowercase.

[c-blake]

It seems the std/ package qualification also changes things...