misc-checkers {valaddin}

Miscellaneous checkers

Description

These functions make check formulae of local scope based on the correspondingly named base R predicates is.* (e.g., vld_data_frame corresponds to the predicate is.data.frame), with the following exceptions:

• vld_empty is based on the predicate length(.) == 0

• vld_formula is based on the predicate typeof(.) == "language" && inherits(., "formula")

• vld_closure is based on the predicate typeof(.) == "closure"

• vld_true and vld_false are based on the predicates identical(., TRUE) and identical(., FALSE), resp.

The checkers vld_true and vld_false are all-purpose checkers to specify arbitrary input validation checks.

Usage

vld_all(...)

vld_any(...)

vld_array(...)

vld_atomic(...)

vld_call(...)

vld_closure(...)

vld_data_frame(...)

vld_empty(...)

vld_environment(...)

vld_expression(...)

vld_factor(...)

vld_false(...)

vld_formula(...)

vld_function(...)

vld_language(...)

vld_list(...)

vld_matrix(...)

vld_na(...)

vld_name(...)

vld_nan(...)

vld_null(...)

vld_numeric(...)

vld_ordered(...)

vld_pairlist(...)

vld_primitive(...)

vld_recursive(...)

vld_symbol(...)

vld_table(...)

vld_true(...)

vld_unsorted(...)

vld_vector(...)

Arguments

...

Check items, i.e., formulae that are one-sided or have a string as left-hand side (see Check Formulae of Local Scope in the documentation page firmly). These are the expressions to check.

Details

Each function vld_* is a function of class "check_maker", generated by localize.

Value

Check formula of local scope.

See Also

Corresponding predicates: all, any, is.array, is.atomic, is.call, is.data.frame, is.environment, is.expression, is.factor, is.function, is.language, is.list, is.matrix, is.na, is.name, is.nan, is.null, is.numeric, is.ordered, is.pairlist, is.primitive, is.recursive, is.symbol, is.table, is.unsorted, is.vector

globalize recovers the underlying check formula of global scope.

The notions of “scope” and “check item” are explained in the Check Formulae section of firmly.

Other checkers: type-checkers, scalar-checkers

Examples

## Not run: 

f <- function(x, y) "Pass"

# Impose the condition that x is a formula
g <- firmly(f, vld_formula(~x))
g(z ~ a + b, 0)  # [1] "Pass"
g(0, 0)          # Error: "Not formula: x"

# Impose the condition that x and y are disjoint (assuming they are vectors)
h <- firmly(f, vld_empty(~intersect(x, y)))
h(letters[1:3], letters[4:5])  # [1] "Pass"
h(letters[1:3], letters[3:5])  # Error: "Not empty: intersect(x, y)"

# Use a custom error message
h <- firmly(f, vld_empty("x, y must be disjoint" ~ intersect(x, y)))
h(letters[1:3], letters[3:5])  # Error: "x, y must be disjoint"

# vld_true can be used to implement any kind of input validation
ifelse_f <- firmly(ifelse, vld_true(~typeof(yes) == typeof(no)))
(w <- {set.seed(1); rnorm(5)})
# [1] -0.6264538  0.1836433 -0.8356286  1.5952808  0.3295078
ifelse_f(w > 0, 0, "1")  # Error: "Not TRUE: typeof(yes) == typeof(no)"
ifelse_f(w > 0, 0, 1)    # [1] 1 0 1 0 0

## End(Not run)