R/odin_parse.R

In richfitz/odin: ODE Generation and Integration

##' Parse an odin model, returning an intermediate representation.
##' The `odin_parse_` version is a "standard evaluation" escape
##' hatch.
##'
##' A schema for the intermediate representation is available in the
##' package as `schema.json`.  It is subject to change at this
##' point.
##'
##' @title Parse an odin model
##'
##' @param x An expression, character vector or filename with the odin
##'   code
##'
##' @param options odin options; see [odin::odin_options].  The
##'   primary options that affect the parse stage are `validate`
##'   and `pretty`.
##'
##' @param type An optional string indicating the the type of input -
##'   must be one of `expression`, `file` or `text` if
##'   provided.  This skips the type detection code used by odin and
##'   makes validating user input easier.
##'
##' @export
##'
##' @seealso [odin::odin_validate], which wraps this function
##'   where parsing might fail, and [odin::odin_build] for
##'   building odin models from an intermediate representation.
##'
##' @examples
##' # Parse a model of exponential decay
##' ir <- odin::odin_parse({
##'   deriv(y) <- -0.5 * y
##'   initial(y) <- 1
##' })
##'
##' # This is odin's intermediate representation of the model
##' ir
##'
##' # If parsing odin models programmatically, it is better to use
##' # odin_parse_; construct the model as a string, from a file, or as a
##' # quoted expression:
##' code <- quote({
##'   deriv(y) <- -0.5 * y
##'   initial(y) <- 1
##' })
##'
##' odin::odin_parse_(code)
odin_parse <- function(x, type = NULL, options = NULL) {
  xx <- substitute(x)
  if (is.symbol(xx)) {
    xx <- force(x)
  } else if (is_call(xx, quote(c)) && all(vlapply(xx[-1], is.character))) {
    ## See #88
    xx <- force(x)
  }
  odin_parse_(xx, options)
}


##' @export
##' @rdname odin_parse
odin_parse_ <- function(x, options = NULL, type = NULL) {
  options <- odin_options(options = options)
  assert_scalar_character_or_null(type)
  ir_parse(x, options, type)
}