trait_methods: Inspect or use a Rust-like explicit trait

In s7contract: Behavioral Contracts and Generative Laws for 'S7'

Inspect or use a Rust-like explicit trait

Description

Inspect or use a Rust-like explicit trait

Usage

trait_methods(trait, inherited = TRUE)

impl_trait(
  trait,
  class,
  methods = list(),
  assoc_types = list(),
  assoc_consts = list(),
  replace = FALSE
)

trait_report(x, trait)

has_trait(x, trait)

assert_trait(x, trait, arg = deparse(substitute(x)))

trait_call(trait, method, x, ...)

trait_assoc_type(trait, x, name)

trait_assoc_const(trait, x, name)

Arguments

trait	A trait created by new_trait().
inherited	Include inherited methods from supertraits?
class	A concrete S7 class, S3 class wrapper, S4 class, or base class wrapper. Register union members separately.
methods	Named list of method implementations. Omitted trait methods use their default implementation when one is available.
assoc_types	Named list of associated type values.
assoc_consts	Named list of associated constant values.
replace	Replace an existing implementation record and silence warnings about visible S7 methods?
x	An object or class.
arg	Name to use in error messages.
method	Method name within the trait.
...	Additional arguments passed to the S7 generic.
name	Associated item name.

Value

trait_methods() returns a named list of trait_method() objects. impl_trait() returns the stored implementation record, invisibly. trait_report() returns a one-row data frame. has_trait() returns a single logical value. assert_trait() returns x, unchanged. trait_call() returns the result of the underlying S7 generic. trait_assoc_type() and trait_assoc_const() return the stored associated item value.

s7contract documentation built on Sept. 10, 2026, 1:09 a.m.