21.10 Known Functions

21.10.1 Unary Operations

unary_op <- function(left, right) {
  new_function(
    exprs(e1 = ),
    expr(
      paste0(!!left, e1, !!right)
    ),
    caller_env()
  )
}

#example
unary_op("\\sqrt{", "}")
#> function (e1) 
#> paste0("\\sqrt{", e1, "}")

21.10.2 Binary Operations

binary_op <- function(sep) {
  new_function(
    exprs(e1 = , e2 = ),
    expr(
      paste0(e1, !!sep, e2)
    ),
    caller_env()
  )
}

#example
binary_op("+")
#> function (e1, e2) 
#> paste0(e1, "+", e2)

Even more LaTeX syntax

known_func_env <- child_env(
  .parent = empty_env(),
  
  # Binary operators
  `+` = binary_op(" + "),
  `-` = binary_op(" - "),
  `*` = binary_op(" * "),
  `/` = binary_op(" / "),
  `^` = binary_op("^"),
  `[` = binary_op("_"),

  # Grouping
  `{` = unary_op("\\left{ ", " \\right}"),
  `(` = unary_op("\\left( ", " \\right)"),
  paste = paste,

  # Other math functions
  sqrt = unary_op("\\sqrt{", "}"),
  sin =  unary_op("\\sin(", ")"),
  cos =  unary_op("\\cos(", ")"),
  tan =  unary_op("\\tan(", ")"),
  log =  unary_op("\\log(", ")"),
  abs =  unary_op("\\left| ", "\\right| "),
  frac = function(a, b) {
    paste0("\\frac{", a, "}{", b, "}")
  },

  # Labelling
  hat =   unary_op("\\hat{", "}"),
  tilde = unary_op("\\tilde{", "}")
)