When a reference class method is accessed with .self$x, it has different behavior from .self[['x']]. The former copies the function to the object's environment (with some attributes attached), and the latter just return NULL (unless it has already been accessed once with .self$x). Is this how it's supposed to work?
Here's an example that illustrates: https://gist.github.com/wch/7013262 TestClass <- setRefClass( 'TestClass', fields = list(a = 'ANY'), methods = list( initialize = function() { e <- environment() pe <- parent.env(e) ppe <- parent.env(pe) # The environment of this object print(ls(pe)) # The environment of the class print(ls(ppe)) # No surprises with fields cat("==================== .self[['a']] ====================\n") print(.self[['a']]) # Getting b these ways isn't quite what we want cat("==================== .self[['b']] ====================\n") print(.self[['b']]) cat("==================== b ====================\n") print(b) # Accessing b with $ works, and it changes things from here on in cat("==================== .self$b ====================\n") print(.self$b) # Now these return the b method with some attributes attached cat("==================== .self[['b']] ====================\n") print(.self[['b']]) cat("==================== b ====================\n") print(b) cat("===============================================\n") print(ls(parent.env(e))) print(ls(parent.env(parent.env(e)))) }, b = function() { "Yes, this is b." } ) ) tc <- TestClass$new() Output: ============================================================ [1] "a" "initialize" [1] "b" "e" "tc" "TestClass" ==================== .self[['a']] ==================== An object of class "uninitializedField" Slot "field": [1] "a" Slot "className": [1] "ANY" ==================== .self[['b']] ==================== NULL ==================== b ==================== function() { "Yes, this is b." } ==================== .self$b ==================== function() { "Yes, this is b." } <environment: 0x5a65418> attr(,"mayCall") character(0) attr(,"name") [1] "b" attr(,"refClassName") [1] "TestClass" attr(,"superClassMethod") [1] "" attr(,"class") [1] "refMethodDef" attr(,"class")attr(,"package") [1] "methods" ==================== .self[['b']] ==================== function() { "Yes, this is b." } <environment: 0x5a65418> attr(,"mayCall") character(0) attr(,"name") [1] "b" attr(,"refClassName") [1] "TestClass" attr(,"superClassMethod") [1] "" attr(,"class") [1] "refMethodDef" attr(,"class")attr(,"package") [1] "methods" ==================== b ==================== function() { "Yes, this is b." } <environment: 0x5a65418> attr(,"mayCall") character(0) attr(,"name") [1] "b" attr(,"refClassName") [1] "TestClass" attr(,"superClassMethod") [1] "" attr(,"class") [1] "refMethodDef" attr(,"class")attr(,"package") [1] "methods" =============================================== [1] "a" "b" "initialize" [1] "b" "e" "tc" "TestClass" -Winston ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
