base (version 3.3)

bquote: Partial substitution in expressions

Description

An analogue of the LISP backquote macro. bquote quotes its argument except that terms wrapped in .() are evaluated in the specified where environment.

Usage

bquote(expr, where = parent.frame())

Arguments

expr

A language object.

where

An environment.

Value

A language object.

See Also

quote, substitute

Examples

require(graphics)

a <- 2

bquote(a == a)
quote(a == a)

bquote(a == .(a))
substitute(a == A, list(A = a))

plot(1:10, a*(1:10), main = bquote(a == .(a)))

## to set a function default arg
default <- 1
bquote( function(x, y = .(default)) x+y )