Class representing a N-ary predicate, bound with an ordered vector of
names for the N (possibly non-distinct) variables
Methods
Method type()
Returns the type of the expression as a string
Returns
type: "SYMBOL", "VALUE", "NULLARY", "UNARY", "BINARY", or "N-ARY" (unimplemented)
Returns the distinct symbols used in the expression
Usage
scidb.expression$symbols()
Returns
vector of symbol names
Method unary()
Whether or not the expression is a function of (at most) a single symbol
Returns
a boolean value indicating unary or non-unary
Method unary_composite()
Whether or not the expression is unary or a boolean AND or OR of
two other in-turn unary composite expressions
Usage
scidb.expression$unary_composite()
Returns
a boolean value indicating unary-composite or not
Renames the symbols in the expression according to replacements in the arguments
Usage
scidb.expression$substitute(...)
Arguments
...optional list of string replacements for each symbol in the expression
Method to_r()
Convert the expression to an R string, with optional symbol substitutions
Usage
scidb.expression$to_r(...)
Arguments
...optional list of string replacements for each symbol in the expression
Returns
evaluation of this predicate as a single R string
Method to_afl()
Convert the expression to an AFL string, with optional symbol substitutions
Usage
scidb.expression$to_afl(...)
Arguments
...optional list of string replacements for each symbol in the expression
Returns
evaluation of this predicate as a single AFL string
Method clone()
The objects of this class are cloneable with this method.
Usage
scidb.expression$clone(deep = FALSE)
Arguments
deepWhether to make a deep clone.