Splice

Span-safe refactoring kernel for 7 languages using tree-sitter and SQLiteGraph.

Version: 0.5.0 License: GPL-3.0-or-later

What This Is

Splice is a command-line tool that performs byte-accurate, AST-validated refactoring operations on code in 7 languages: Rust, Python, C, C++, Java, JavaScript, and TypeScript. It can replace function bodies, delete symbols, apply batch changes, perform pattern replacements, and undo operations.

NEW in v0.5.0: Magellan integration for code indexing and label-based symbol discovery.

What This Is NOT

• An IDE or LSP server - Use Rust Analyzer, IntelliJ, PyCharm, VSCode, or your editor
• A general-purpose refactoring tool - Focused on specific operations
• A complete solution - It's a focused tool for specific jobs
• Production-hardened - Use with version control

What It Does

• patch: Replace function bodies, class definitions, enum variants with validation (single or batch)
• delete: Remove symbol definitions and all references (cross-file, Rust-only)
• apply-files: Multi-file pattern replacement with AST confirmation
• query: Query symbols by labels using Magellan integration (NEW)
• get: Get code chunks from the database without re-reading files (NEW)
• undo: Restore files from backup manifest
• plan: Orchestrate multi-step refactors via JSON plans
• preview: Inspect changes before applying (dry-run mode)
• backup: Create backups with automatic restore capability
• Validates syntax with tree-sitter after every operation
• Validates compilation with language-specific compilers
• Rolls back atomically on any failure

Supported Languages

Language	Extensions	Delete	Patch	Validation
Rust	.rs	Full	Full	cargo check
Python	.py	Basic	Full	python -m py_compile
C	.c, .h	Basic	Full	gcc -fsyntax-only
C++	.cpp, .hpp, .cc, .cxx	Basic	Full	g++ -fsyntax-only
Java	.java	Basic	Full	javac
JavaScript	.js, .mjs, .cjs	Basic	Full	node --check
TypeScript	.ts, .tsx	Basic	Full	tsc --noEmit

Delete modes:

• Full: Finds all references across files (Rust only)
• Basic: Deletes definition only, no reference finding (other languages)

Installation

cargo install splice

Or from source:

git clone https://github.com/oldnordic/splice.git
cd splice
cargo build --release
cp target/release/splice ~/.local/bin/

Quick Start

Delete a Symbol (Rust)

Delete a function and all its references:

splice delete --file src/lib.rs --symbol helper --kind function

Output:

Deleted 'helper' (3 references + definition) across 2 file(s).

Patch a Symbol (Rust)

Replace a function body:

cat > new_greet.rs << 'EOF'
pub fn greet(name: &str) -> String {
    format!("Hi, {}!", name)
}
EOF

splice patch --file src/lib.rs --symbol greet --kind function --with new_greet.rs

Patch a Symbol (Python)

cat > new_calc.py << 'EOF'
def calculate(x: int, y: int) -> int:
    return x * y
EOF

splice patch --file utils.py --symbol calculate --language python --with new_calc.py

Patch a Symbol (TypeScript)

cat > new_fn.ts << 'EOF'
function calculate(x: number, y: number): number {
    return x * y;
}
EOF

splice patch --file src/math.ts --symbol calculate --language type-script --with new_fn.ts

Multi-Step Plan

cat > plan.json << 'EOF'
{
  "steps": [
    {
      "file": "src/lib.rs",
      "symbol": "foo",
      "kind": "function",
      "with": "patches/foo.rs"
    },
    {
      "file": "src/lib.rs",
      "symbol": "bar",
      "kind": "function",
      "with": "patches/bar.rs"
    }
  ]
}
EOF

splice plan --file plan.json

Batch Patch

Apply multiple patches at once from a JSON file:

cat > batch.json << 'EOF'
{
  "patches": [
    {
      "file": "src/lib.rs",
      "symbol": "foo",
      "kind": "function",
      "with": "patches/foo.rs"
    },
    {
      "file": "src/lib.rs",
      "symbol": "bar",
      "kind": "function",
      "with": "patches/bar.rs"
    }
  ]
}
EOF

splice patch --batch batch.json --language rust

Pattern Replace

Replace a pattern across multiple files:

# Replace "42" with "99" in all Python files
splice apply-files --glob "*.py" --find "42" --replace "99"

# With validation and backup
splice apply-files --glob "tests/**/*.rs" --find "old_func" --replace "new_func" --create-backup

Preview Mode

Inspect changes before applying:

splice patch --file src/lib.rs --symbol foo --with new_foo.rs --preview

Backup and Undo

Create a backup before changes:

splice patch --file src/lib.rs --symbol foo --with new_foo.rs --create-backup --operation-id "my-change"

Restore from backup:

splice undo --manifest .splice-backup/my-change/manifest.json

Query Symbols by Label (Magellan Integration)

# List all available labels
splice query --db code.db --list

# Find all Rust functions
splice query --db code.db --label rust --label fn

# Show code for each result
splice query --db code.db --label struct --show-code

Get Code Chunks (Magellan Integration)

# Get code by byte span without re-reading the file
splice get --db code.db --file src/lib.rs --start 0 --end 100

Commands

splice delete

Remove a symbol definition and all its references.

splice delete --file <PATH> --symbol <NAME> [--kind <KIND>] [--language <LANG>]

Optional Arguments:

• --kind <KIND>: Symbol kind filter
• --language <LANG>: Language override
• --analyzer <MODE>: Validation mode (off, os, path)
• --create-backup: Create backup before deleting
• --operation-id <ID>: Custom operation ID for auditing
• --metadata <JSON>: Optional metadata attachment

Rust-specific features:

• Finds references across the entire workspace
• Tracks imports and re-exports
• Handles shadowing correctly
• Cross-file reference resolution

Other languages:

• Deletes the symbol definition only
• Use with --language flag or auto-detection from file extension

splice patch

Apply a patch to a symbol's span.

splice patch --file <PATH> --symbol <NAME> --with <FILE> [--kind <KIND>] [--language <LANG>]

Optional Arguments:

• --kind <KIND>: Symbol kind filter (function, method, class, struct, interface, enum, trait, impl, module, variable, constructor, type-alias)
• --language <LANG>: Language override (rust, python, c, cpp, java, java-script, type-script)
• --analyzer <MODE>: Validation mode (off, os, path)
• --preview: Run in preview mode without modifying files
• --batch <FILE>: JSON file describing batch replacements
• --create-backup: Create backup before patching
• --operation-id <ID>: Custom operation ID for auditing
• --metadata <JSON>: Optional metadata attachment

splice apply-files

Apply a pattern replacement to multiple files.

splice apply-files --glob <GLOB> --find <PATTERN> --replace <REPLACEMENT>

Required Arguments:

• --glob <GLOB>: Glob pattern for matching files (e.g., tests/**/*.rs, src/**/*.py)
• --find <PATTERN>: Text pattern to find
• --replace <REPLACEMENT>: Replacement text

Optional Arguments:

• --language <LANG>: Language override (auto-detected from extension by default)
• --no-validate: Skip validation gates
• --create-backup: Create backup before applying
• --operation-id <ID>: Custom operation ID for auditing
• --metadata <JSON>: Optional metadata attachment

splice undo

Undo a previous operation by restoring from a backup manifest.

splice undo --manifest <PATH>

splice plan

Execute a multi-step refactoring plan.

splice plan --file <PLAN.json>

splice query

Query symbols by labels using Magellan integration.

splice query --db <FILE> [--label <LABEL>]... [--list] [--count] [--show-code]

Optional Arguments:

• --db <FILE>: Path to the Magellan database (required)
• --label <LABEL>: Label to query (can be specified multiple times for AND semantics)
• --list: List all available labels with counts
• --count: Count entities with specified label(s)
• --show-code: Show source code for each result

Available labels:

• Language labels: rust, python, javascript, typescript, c, cpp, java
• Symbol kind labels: fn, method, struct, class, enum, interface, module, union, namespace, typealias

splice get

Get code chunks from the database using Magellan integration.

splice get --db <FILE> --file <PATH> --start <N> --end <N>

Required Arguments:

• --db <FILE>: Path to the Magellan database
• --file <PATH>: File path
• --start <N>: Start byte offset
• --end <N>: End byte offset

Documentation

• manual.md - Complete user manual
• CHANGELOG.md - Version history
• docs/DIAGNOSTICS_HUMAN_LLM.md - CLI diagnostics contract for humans and LLMs, including rust-analyzer and multi-language validation output

Requirements

• Rust 1.70+ (for building)
• Language-specific compilers (for validation):
  • Rust: cargo
  • Python: python
  • C/C++: gcc/g++
  • Java: javac
  • JavaScript: node
  • TypeScript: tsc

Architecture

• src/cli/ - CLI argument parsing
• src/ingest/ - Symbol parsing for 7 languages
• src/graph/ - SQLiteGraph integration
• src/resolve/ - Symbol resolution and reference finding
• src/patch/ - Span-safe replacement + validation + batch operations + pattern replace + backup
• src/validate/ - Tree-sitter + compiler validation gates
• src/plan/ - JSON plan orchestration

Validation Gates

Every operation passes:

1. UTF-8 boundary validation
2. Tree-sitter reparse (syntax check)
3. Language-specific compiler check (cargo check, python -m py_compile, etc.)

Testing

cargo test

Test Coverage: 334/334 tests passing

Feedback

If you use this tool and find a bug or miss a feature that would be useful, drop a line. It's appreciated.

License

GPL-3.0-or-later

Disclaimer

This software modifies source code. Always commit your changes before running Splice.