R Oop

R Object-Oriented Programming

S7, S3, S4, and vctrs: choosing the right OOP system for your needs

S7: Modern OOP for New Projects

• S7 combines S3 simplicity with S4 structure
• Formal class definitions with automatic validation
• Compatible with existing S3 code

# S7 class definition
Range = @start"
    }
  }
)

# Usage - constructor and property access
x = x@start & y = @start"
  }
)

# Multiple dispatch needs
method(generic, list(ClassA, ClassB))  S7**: Usually 1-2 hours work, keeps full compatibility
2. **S4 -> S7**: More complex, evaluate if S4 features are actually needed
3. **Base R -> vctrs**: For vector-like classes, significant benefits
4. **Combining approaches**: S7 classes can use vctrs principles internally

### Migration Example: S3 to S7

```r
# Original S3
new_person_s3 <- function(name, age) {
  structure(list(name = name, age = age), class = "person")
}

# Migrated S7
Person <- new_class("Person",
  properties = list(
    name = class_character,
    age = class_numeric
  )
)

# S7 is backwards compatible with S3 generics
# Existing S3 methods still work

When NOT to Use OOP

Sometimes simpler approaches are better:

# Don't create a class for simple data
# BAD
Point <- new_class("Point", properties = list(x = class_double, y = class_double))

# GOOD - just use a named list or vector
point <- c(x = 1.5, y = 2.3)

# Don't create classes for one-off operations
# Use functions instead
distance <- function(p1, p2) {
  sqrt((p1["x"] - p2["x"])^2 + (p1["y"] - p2["y"])^2)
}

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: ab604
• Source: ab604/claude-code-r-skills
• License: MIT

Install and usage instructions live in the source repository linked above.