scidb.expression: Virtual base expression class

In Paradigm4/SciDBR: An R Interface to SciDB

Virtual base expression class

Description

Class representing a N-ary predicate, bound with an ordered vector of names for the N (possibly non-distinct) variables

Methods

Public methods

• scidb.expression$type()

• scidb.expression$symbols()

• scidb.expression$unary()

• scidb.expression$unary_composite()

• scidb.expression$substitute()

• scidb.expression$to_r()

• scidb.expression$to_afl()

• scidb.expression$clone()

---

Method type()

Returns the type of the expression as a string

Usage

scidb.expression$type()

Returns

type: "SYMBOL", "VALUE", "UNARY", "BINARY", or "TERNARY" (unimplemented)

---

Method symbols()

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

Usage

scidb.expression$unary()

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

---

Method substitute()

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

deep

Whether to make a deep clone.

Paradigm4/SciDBR documentation built on Nov. 9, 2023, 4:58 a.m.