start adding YAML interop

Author: JohnMount

DESCRIPTION

@@ -1,8 +1,8 @@
 Package: cdata
 Type: Package
 Title: Fluid Data Transformations
-Version: 1.1.1
-Date: 2019-07-24
+Version: 1.1.2
+Date: 2019-09-15
 Authors@R: c(
     person("John", "Mount", email = "jmount@win-vector.com", role = c("aut", "cre")),
     person("Nina", "Zumel", email = "nzumel@win-vector.com", role = c("aut")),

NEWS.md

@@ -1,4 +1,8 @@
 
+# cdata 1.1.2 2019/09/15
+
+ * Add data_algebra interop.
+
 # cdata 1.1.1 2019/07/24
 
  * Fix some newly dead links.

R/cdata_yaml.R

@@ -0,0 +1,74 @@
+
+convert_yaml_to_data_frame <- function(obj) {
+  n <- length(obj)
+  if (n<1) {
+    return(NULL)
+  }
+  n1 = names(obj)[[1]]
+  d = data.frame(x = obj[[n1]],
+                 stringsAsFactors = FALSE)
+  colnames(d) <- n1
+  if (n<2) {
+    return(d)
+  }
+  for (i in (2:n)) {
+    ni = names(obj)[[i]]
+    d[[ni]] <- obj[[ni]]
+  }
+  return(d)
+}
+
+convert_yaml_to_record_spec <- function(obj) {
+  record_keys <- NULL
+  control_table_keys <- NULL
+  if ("record_keys" %in% names(obj)) {
+    record_keys = obj$record_keys
+  }
+  if ("control_table_keys" %in% names(obj)) {
+    control_table_keys = obj$control_table_keys
+  }
+  control_table <- convert_yaml_to_data_frame(obj$control_table)
+  return(list('record_keys' = record_keys,
+              'control_table_keys' = control_table_keys,
+              'control_table' = control_table))
+}
+
+#' Read a cdata record transform from a simple object (such as is imported from YAML).
+#'
+#' @param obj object to convert
+#' @return cdata transform specification
+#'
+#' @export
+#'
+convert_yaml_to_cdata_spec <- function(obj) {
+  blocks_in = NULL
+  blocks_out = NULL
+  if ("blocks_out"  %in% names(obj)) {
+    blocks_out = convert_yaml_to_record_spec(obj$blocks_out)
+  }
+  if ("blocks_in"  %in% names(obj)) {
+    blocks_in = convert_yaml_to_record_spec(obj$blocks_in)
+  }
+  # TODO: work on check/strict options
+  if ((!is.null(blocks_in)) && (!is.null(blocks_out))) {
+    # TODO: work on recordKeys point
+    return(cdata::layout_specification(incoming_shape = blocks_in$control_table,
+                                       outgoing_shape = blocks_out$control_table,
+                                       recordKeys = blocks_in$record_keys,
+                                       incoming_controlTableKeys = blocks_in$control_table_keys,
+                                       outgoing_controlTableKeys = blocks_out$control_table_keys))
+  }
+  if (!is.null(blocks_in)) {
+    return(blocks_to_rowrecs_spec(controlTable = blocks_in$control_table,
+                                  recordKeys = blocks_in$record_keys,
+                                  controlTableKeys = blocks_in$control_table_keys))
+  }
+  if (!is.null(blocks_out)) {
+    return(rowrecs_to_blocks_spec(controlTable = blocks_out$control_table,
+                                  recordKeys = blocks_out$record_keys,
+                                  controlTableKeys = blocks_out$control_table_keys))
+  }
+  return(NULL)
+}
+
+# TODO: cdata to yaml