Perhaps I don't understand how :multi works (and I would love to see more
documentation and will even write tests, as I don't think the existing ones
cover all of the cases).
I added a custom Cons class to Pheme, as that's what a Lisp/Scheme needs.
This means that I also need some more logic for is_deeply() to compare two
Cons objects appropriately.
The attached patch is my first attempt. It doesn't work and I'm not sure why.
I don't know if installing is() from Test::More (it's a multi sub) overrides
the multi is() in Pheme::Test. I don't know if dispatch even *gets* to my
custom is() either.
I don't even know if what I'm trying to do should be possible, at least the
way I'm doing it.
I'm stumped and I appreciate any advice, especially from someone who knows how
multi dispatch ought to work in Parrot and someone who knows how the current
system does work.
-- c
=== lib/PhemeSymbols.pir
==================================================================
--- lib/PhemeSymbols.pir (revision 16710)
+++ lib/PhemeSymbols.pir (local)
@@ -15,14 +15,77 @@
.return()
.end
+.namespace [ 'Pheme::Cons' ]
+
+.sub _initialize :load
+ .local pmc cons_class
+ newclass cons_class, 'Pheme::Cons'
+
+ addattribute cons_class, 'head'
+ addattribute cons_class, 'tail'
+.end
+
+.sub 'head' :method
+ .param pmc new_head :optional
+ .param int have_head :opt_flag
+
+ unless have_head goto return_head
+ setattribute self, 'head', new_head
+ .return( new_head )
+
+ return_head:
+ .local pmc head
+ head = getattribute self, 'head'
+ .return( head )
+.end
+
+.sub __get_integer :method
+ .local pmc elem
+ elem = self.'head'()
+
+ .local int elem_defined
+ elem_defined = defined elem
+
+ if elem_defined goto count_tail
+ .return( 0 )
+
+ count_tail:
+ .local int count
+ count = 0
+ elem = self
+
+ loop_start:
+ inc count
+ elem = elem.'tail'()
+ elem_defined = defined elem
+ if elem_defined goto loop_start
+
+ loop_end:
+ .return( count )
+.end
+
+.sub 'tail' :method
+ .param pmc new_tail :optional
+ .param int have_tail :opt_flag
+
+ unless have_tail goto return_tail
+ setattribute self, 'tail', new_tail
+ .return( new_tail )
+
+ return_tail:
+ .local pmc tail
+ tail = getattribute self, 'tail'
+ .return( tail )
+.end
+
.namespace [ 'Pheme' ]
-.sub __resolve_at_runtime :multi( ResizablePMCArray )
- .param pmc args
- .param pmc more_args :slurpy
+.sub __resolve_at_runtime :multi( Pheme::Cons )
+ .param pmc args :slurpy
- unshift more_args, args
- .return( more_args )
+ .local pmc result
+ result = __list_to_cons( args :flat )
+ .return( result )
.end
.sub __resolve_at_runtime :multi( string )
@@ -40,48 +103,50 @@
.return( result )
return_list:
- unshift args, symbol_name
- .return( args )
+
+ result = __list_to_cons( symbol_name, args :flat )
+ .return( result )
.end
-.sub car
- .param pmc list
+.sub __list_to_cons
+ .param pmc args :slurpy
- .local int count
- count = list
+ .local int cons_type
+ cons_type = find_type 'Pheme::Cons'
- if count > 0 goto really_car
- .return( list )
+ .local pmc result
+ result = new cons_type
- really_car:
- .local pmc first_item
- first_item = list[0]
+ .local int args_count
+ .local pmc arg
- .return( first_item )
+ loop_start:
+ args_count = args
+ unless args_count goto loop_end
+ arg = pop args
+ result = cons( arg, result )
+ goto loop_start
+
+ loop_end:
+ .return( result )
.end
-.sub cdr
- .param pmc list
+.sub car
+ .param pmc cons
- .local pmc iter
- iter = new .Iterator, list
- iter = 0
+ .local pmc head
+ head = cons.'head'()
- .local pmc result
- result = new .ResizablePMCArray
+ .return( head )
+.end
- # skip the first element
- .local pmc elem
- elem = shift iter
+.sub cdr
+ .param pmc cons
- iter_loop:
- unless iter goto iter_end
- elem = shift iter
- push result, elem
- goto iter_loop
+ .local pmc tail
+ tail = cons.'tail'()
- iter_end:
- .return( result )
+ .return( tail )
.end
.sub include_file
@@ -98,9 +163,16 @@
.param pmc l
.param pmc r
- unshift r, l
+ .local int cons_type
+ cons_type = find_type 'Pheme::Cons'
- .return( r )
+ .local pmc result
+ result = new cons_type
+
+ result.'head'( l )
+ result.'tail'( r )
+
+ .return( result )
.end
.sub 'write' :multi()
@@ -130,6 +202,11 @@
.sub __make_empty_cons
.local pmc result
- result = new .ResizablePMCArray
+
+ .local int cons_type
+ cons_type = find_type 'Pheme::Cons'
+
+ .local pmc result
+ result = new cons_type
.return( result )
.end
=== lib/PhemeTest.pir
==================================================================
--- lib/PhemeTest.pir (revision 16710)
+++ lib/PhemeTest.pir (local)
@@ -13,78 +13,20 @@
diag = find_global 'Test::More', 'diag'
is_deeply = find_global 'Test::More', 'is_deeply'
- store_global 'Pheme', 'plan', plan
- store_global 'Pheme', 'is', is
- store_global 'Pheme', 'ok', ok
- store_global 'Pheme', 'diag', diag
+ store_global 'Pheme', 'plan', plan
+ store_global 'Pheme', 'is', is
+ store_global 'Pheme', 'ok', ok
+ store_global 'Pheme', 'diag', diag
store_global 'Pheme', 'is_deeply', is_deeply
.end
-=cut
-
.namespace[ 'Pheme' ]
-.sub _is :multi( ResizablePMCArray, ResizablePMCArray )
- .param pmc l_list
- .param pmc r_list
+.sub is :multi( Pheme::Cons, Pheme::Cons )
+ .param pmc l_cons
+ .param pmc r_cons
.param string diagnostic :optional
- .local int l_count
- .local int r_count
- l_count = l_list
- r_count = r_list
-
- .local string explanation
- .local string num_to_s
-
- if l_count == r_count goto check_items
-
- explanation = 'Expected has '
- num_to_s = l_count
- explanation .= num_to_s
- explanation .= ' elements, Received has '
- num_to_s = r_count
- explanation .= num_to_s
- explanation .= ' elements'
-
- ok( 0, diagnostic )
- diag( explanation )
- .return()
-
- check_items:
- .local int i
- i = 0
-
- .local pmc l_elem
- .local pmc r_elem
-
- loop_start:
- if i == l_count goto loop_end
- l_elem = l_list[i]
- r_elem = r_list[i]
- eq l_elem, r_elem, pass_this_index
- ok( 0, diagnostic )
-
- explanation = 'Elements mismatched at index '
- num_to_s = i
- explanation .= num_to_s
- explanation .= ', ('
- num_to_s = l_elem
- explanation .= num_to_s
- explanation .= '), ('
- num_to_s = r_elem
- explanation .= num_to_s
- explanation .= ')'
- diag( explanation )
- .return()
-
- pass_this_index:
- inc i
- goto loop_start
-
- loop_end:
- ok( 1, diagnostic )
- .return()
+ print "Found correct is!\n"
+ .return( 0 )
.end
-
-=cut
=== lib/post2pir.tg
==================================================================
--- lib/post2pir.tg (revision 16710)
+++ lib/post2pir.tg (local)
@@ -4,7 +4,7 @@
.namespace [ 'Pheme' ]
.sub __onload :anon :load
- load_bytecode 'lib/PhemeSymbols.pbc'
+# load_bytecode 'lib/PhemeSymbols.pbc'
main()
.end
