Atomic Identifiers

Overview

Atomic identifiers allow you to treat compound brand names and identifiers as indivisible units during case transformations. When an identifier is marked as atomic, Renamify preserves it as a single word without detecting internal word boundaries.

This feature is essential for maintaining brand identity and preventing incorrect word splitting in compound names like “DocSpring” or “GitHub”.

The Problem

Without atomic mode, compound identifiers are split at word boundaries:

# Without atomic mode
DocSpring → doc_spring (snake_case)
DocSpring → doc-spring (kebab-case)
DocSpring → DOC_SPRING (SCREAMING_SNAKE_CASE)

These transformations break the brand identity and can cause issues when the name should remain as a single unit.

The Solution

With atomic identifiers, compound identifiers are preserved as single units:

# With atomic mode
DocSpring → docspring (snake_case)
DocSpring → docspring (kebab-case)
DocSpring → DOCSPRING (SCREAMING_SNAKE_CASE)
DocSpring → DocSpring (PascalCase - preserved)

With Atomic Identifiers

Command Line Flags

You can enable atomic identifiers using CLI flags:

Both atomic

# Both search and replace terms are atomic
renamify rename FormAPI DocSpring --atomic-identifiers

Search only

# Only search term is atomic
renamify rename FormAPI Helper --atomic-search

Replace only

# Only replace term is atomic
renamify rename OldName DocSpring --atomic-replace

Configuration File

You can configure commonly used atomic identifiers in .renamify/config.toml:

# List of identifiers that should always be treated as atomic
atomic = ["DocSpring", "GitHub", "FormAPI"]

When configured identifiers are detected, they’re automatically treated as atomic without needing CLI flags.

Overriding Configuration

You can override the configuration file settings:

# Override config to allow word boundaries
renamify rename DocSpring doc_spring --no-atomic-search

# Override for search term only
renamify rename DocSpring Helper --no-atomic-search

# Override for replace term only
renamify rename OldName DocSpring --no-atomic-replace

Real-World Examples

Renaming a Brand Name

When renaming “FormAPI” to “DocSpring” with atomic mode:

renamify rename FormAPI DocSpring --atomic-identifiers

Results:

• FormAPIController → DocSpringController
• formapi_client → docspring_client
• FORMAPI_TOKEN → DOCSPRING_TOKEN
• useFormAPIHook → useDocSpringHook

Partial Matching

Atomic identifiers are preserved even when they appear as part of larger identifiers:

# GitHub is atomic
GitHubActions → GitHubActions (preserved in PascalCase)
github_api → github_api (preserved as single unit)
GITHUB_TOKEN → GITHUB_TOKEN (preserved as single unit)

Case Transformation Behavior

When an identifier is atomic, case transformations follow these rules:

Case Style	Non-Atomic	Atomic
snake_case	doc_spring	docspring
kebab-case	doc-spring	docspring
camelCase	docSpring	docspring
PascalCase	DocSpring	DocSpring
SCREAMING_SNAKE_CASE	DOC_SPRING	DOCSPRING
Train-Case	Doc-Spring	Docspring
lowercase	docspring	docspring
UPPERCASE	DOCSPRING	DOCSPRING

VS Code Extension

The VS Code extension provides checkboxes for atomic mode:

• Atomic search: Treat the search term as an indivisible unit
• Atomic replace: Treat the replace term as an indivisible unit

These checkboxes include tooltips explaining their behavior and are automatically checked when terms match configured atomic identifiers.

Best Practices

1. Configure Common Brand Names: Add frequently used brand names to your .renamify/config.toml
2. Use for Compound Words: Apply atomic mode to compound brand names and technical terms that should remain unified
3. Consider Context: Use atomic mode when the identifier’s meaning depends on being a single unit
4. Test First: Use --dry-run to preview how atomic mode affects your renaming

Technical Details

How It Works

1. Token Parsing: When atomic mode is enabled, the identifier bypasses normal word boundary detection
2. Variant Generation: Only case variants are generated, not word-separated variants
3. Pattern Matching: The atomic identifier is matched and replaced as a complete unit

Performance

Atomic mode has minimal performance impact:

• Detection happens during the parsing phase
• No additional scanning or regex operations required
• Config file is cached after first read

Limitations

• Atomic mode applies to the entire identifier - you cannot make part of an identifier atomic
• Case-insensitive matching is used for configured atomic identifiers
• Atomic identifiers should not contain delimiters (underscores, hyphens, etc.)

See Also

• Case Transformations - Learn about supported case styles
• Configuration - Set up persistent atomic identifiers
• CLI Reference - Full command options