Associative transformation of ggplot

assoc.R

setClass("ggthing", representation(content="call"))
setClass("ggthings",representation(contents="list"))


bracket<-function(e1) NULL
setGeneric("bracket")

setMethod("bracket",c("ggthing"),
  function(e1){
  	new("ggthings",contents=list(e1@content))
  }
)

setMethod("bracket",c("ggthings"),
  function(e1){
  	new("ggthings",contents=list(e1@contents))
  }
)


setMethod("+",c("ggthing","ggthing"),
  function(e1,e2){
  	new("ggthings",contents=c(e1@content,e2@content))
  }
)


setMethod("+",c("ggthings","ggthing"),
  function(e1,e2){
  	new("ggthings",contents=c(e1@contents,e2@content))
  }
)

setMethod("+",c("ggthing","ggthings"),
  function(e1,e2){
  	new("ggthings",contents=c(e1@content,e2@contents))
  }
)


setMethod("+",c("ggthings","ggthings"),
  function(e1,e2){
  	new("ggthings",contents=c(e1@contents,e2@contents))
  }
)

render<-function(e1) NULL
setGeneric("render")

setMethod("render","ggthing",function(e1) eval(print(e1@content)))


setMethod("render","ggthings",function(e1){
	l<-c(e1@contents,recursive=TRUE)
	g<-Reduce(function(e1,e2) bquote(.(e1)+.(e2)),l)
	eval(print(g))
}
)

library(DHBins)
ggplot(immune)+geom_map(aes(map_id=DHB,fill=Pcttotal),map=dhmap_hex())+expand_limits(dhmap_hex())+coord_fixed()

a<-new("ggthing",content=quote(ggplot(immune)))
b<-new("ggthing",content=quote(geom_map(aes(map_id=DHB,fill=Pcttotal),map=dhmap_hex())))
c<-new("ggthing",content=quote(expand_limits(dhmap_hex())))
d<-new("ggthing",content=quote(coord_fixed()))

one <- a+b+c+d
two <- a+bracket(b+c+d)
three<-a+b+bracket(c+d)

render(one)
render(two)
render(three)