demo_st_deparse.R

demo_st_deparse.R

require('sourcetools')

get_index <- function(col, width, control) {
  if (control == 'forward') {
    temp <- col[col<=width]
    return(which(col==max(temp)))
  } else {
    temp <- col[col>=width]
    return(which(col==min(temp)))
  }
}

st_deparce <- function(tokens, width.cutoff, control) {
  if (max(tokens$column) <= width.cutoff) { # TODO: wrong boundary condition
    return(paste(tokens$value, collapse=""))
  }
  index <- get_index(tokens$column, width.cutoff, control)
  if (tokens$width[index]>1) {
    if (control == 'forward') {
      index <- index - 1
    } else {
      index <- index + 1
    }
  }

  if (index >= nrow(tokens) || index == 0) {
    return(paste(tokens$value, collapse = ""))
  }
  rest <- tokens[(index+1):nrow(tokens), ]
  rest$column <- rest$column - min(rest$column) + 1
  st_deparce(rest, width.cutoff, control)
  print(c(paste(tokens$value[1:index], collapse = "")))
  return(c(paste(tokens$value[1:index], collapse = ""),
        st_deparce(rest, width.cutoff, control)))
}


test <- "lm( weight ~ group )"
test_tokens <- tokenize_string(test)
test_tokens$width <- lapply(test_tokens$value, nchar)

res1 <- st_deparce(test_tokens, 7, 'forward')
res2 <- st_deparce(test_tokens, 7, 'backward')
print(paste(res1, collapse = '\n'))
# lm( 
# weight 
# ~ 
# group )
print(paste(res2, collapse = '\n'))
# lm( weight 
# ~ group
# )