r_term:r_expression/4

Grammar that creates an R command from a Prolog term. Terms recognised:

The atoms true and false are mapped to TRUE and FALSE.
Other Prolog atoms are mapped to an R name. If required, the name is quoted using backquotes.
A term +(Atom) is mapped to an R string.
A Prolog string is mapped to an R string. The server should run in UTF-8 mode for exchange of Unicode data.
A Prolog number is mapped to an R number.
A Prolog list is added to Assignments. These are used to create a temporary R variable. The R command translation contains the variable name
Left$Right is translated as is.
An array index X[I,...] is translated as is. Empty elements in the index, e.g., the R expression a[,3] can be written as `a['',3]`, `a[-,3] or a[*,3]`.
Known operators are passed as infix operators. The following operators are known: +, -, *, /, mod, '%%', ^, >=, >, ==, <, <=, =<, \=, '!=', :, <-
Expr1,Expr2 is translated into two R statements separated by a newline.
{Expr1 ; ...; ExprN} is translated into two R statements separated by a semicolon, and the result of ExprN is returned.
Compound terms are translated to function calls.

This library loads r_expand_dot.pl, which uses the `.` infix operator to make a.b and a.b() valid syntax.

Arguments:

Assignments

- is a list Name=Value for data assignments.