make_rule {sketch}

Make a AST transformation rule

Description

Make a AST transformation rule

Usage

make_rule(from, to)

Arguments

from

A character string.

to

A character string.

Value

A function that takes a language object and returns a language object.

Examples

library(sketch)

rule_1 <- make_rule("pi", "Math.PI")
expr <- rlang::parse_expr("2 * (3 + pi)")

rule_1(expr)  # this works but is not the preferred usage
rewrite(expr, list(rule_1))  # this is preferred

rule_2 <- make_rule("+", "Math.add")
rewrite(expr, list(rule_1, rule_2))