2021-11-28 | Paul Boddie | file changeset files shortlog | Introduced support for values that can be allocated on a special thread-local stack, copied around and overwritten/mutated, demonstrating the concept using integer and floating-point numbers. Various complications arise with special attributes (such as __data__) due to the way references are tagged to indicate mutable values, and attribute slots must be cleared in locals, objects and fragments before values are stored since target slots are tested for mutable values. | tagged-address-values |
paul@2 | 1 | class C: |
paul@2 | 2 | def m(self): |
paul@2 | 3 | return 1 |
paul@2 | 4 | |
paul@2 | 5 | D = C # alias for C |
paul@2 | 6 | |
paul@266 | 7 | print C # __main__.C |
paul@266 | 8 | print D # __main__.C |
paul@248 | 9 | |
paul@2 | 10 | class E: |
paul@2 | 11 | def m(self): |
paul@2 | 12 | return 2 |
paul@2 | 13 | |
paul@2 | 14 | F = E # alias for E |
paul@2 | 15 | |
paul@266 | 16 | print E # __main__.E |
paul@266 | 17 | print F # __main__.E |
paul@248 | 18 | |
paul@2 | 19 | def f(): |
paul@2 | 20 | c = C |
paul@2 | 21 | d = D # C |
paul@2 | 22 | cm = C.m |
paul@2 | 23 | dm = D.m # C.m |
paul@2 | 24 | |
paul@266 | 25 | print c # __main__.C |
paul@266 | 26 | print d # __main__.C |
paul@266 | 27 | print cm # __main__.C.m |
paul@266 | 28 | print dm # __main__.C.m |
paul@248 | 29 | |
paul@2 | 30 | c = E |
paul@2 | 31 | d = F # E |
paul@2 | 32 | cm = E.m |
paul@2 | 33 | dm = F.m # E.m |
paul@2 | 34 | |
paul@266 | 35 | print c # __main__.E |
paul@266 | 36 | print d # __main__.E |
paul@266 | 37 | print cm # __main__.E.m |
paul@266 | 38 | print dm # __main__.E.m |
paul@248 | 39 | |
paul@248 | 40 | f() |
paul@248 | 41 | |
paul@2 | 42 | Cm = C.m |
paul@2 | 43 | Dm = D.m |
paul@2 | 44 | Em = E.m |
paul@2 | 45 | Fm = F.m |
paul@2 | 46 | |
paul@266 | 47 | print Cm # __main__.C.m |
paul@266 | 48 | print Dm # __main__.C.m |
paul@266 | 49 | print Em # __main__.E.m |
paul@266 | 50 | print Fm # __main__.E.m |
paul@248 | 51 | |
paul@2 | 52 | def g(): |
paul@2 | 53 | Cm = E.m |
paul@2 | 54 | Dm = F.m # E.m |
paul@2 | 55 | |
paul@266 | 56 | print Cm # __main__.E.m |
paul@266 | 57 | print Dm # __main__.E.m |
paul@248 | 58 | |
paul@248 | 59 | g() |
paul@248 | 60 | |
paul@2 | 61 | def h(): |
paul@2 | 62 | global Em, Fm |
paul@2 | 63 | Em = C.m |
paul@2 | 64 | Fm = D.m # C.m |
paul@2 | 65 | |
paul@266 | 66 | print Em # __main__.C.m |
paul@266 | 67 | print Fm # __main__.C.m |
paul@248 | 68 | |
paul@248 | 69 | h() |
paul@248 | 70 | |
paul@266 | 71 | print Em # __main__.C.m |
paul@266 | 72 | print Fm # __main__.C.m |
paul@251 | 73 | |
paul@2 | 74 | Ci = C() |
paul@2 | 75 | Ei = E() |
paul@2 | 76 | |
paul@266 | 77 | print Ci # <__main__.C instance> |
paul@266 | 78 | print Ei # <__main__.E instance> |
paul@248 | 79 | |
paul@2 | 80 | def i(): |
paul@2 | 81 | c = Ci |
paul@266 | 82 | print c # <__main__.C instance> |
paul@2 | 83 | c = Ei |
paul@266 | 84 | print c # <__main__.E instance> |
paul@248 | 85 | |
paul@248 | 86 | i() |
paul@2 | 87 | |
paul@2 | 88 | def j(): |
paul@2 | 89 | global Ei |
paul@2 | 90 | Ei = C() |
paul@266 | 91 | print Ei # <__main__.C instance> |
paul@248 | 92 | |
paul@248 | 93 | j() |
paul@2 | 94 | |
paul@266 | 95 | print Ei # <__main__.C instance> |
paul@251 | 96 | |
paul@2 | 97 | L = [] |
paul@2 | 98 | M = [1] |
paul@2 | 99 | |
paul@248 | 100 | print L # [] |
paul@248 | 101 | print M # [1] |
paul@248 | 102 | |
paul@2 | 103 | def k(): |
paul@2 | 104 | c = L |
paul@248 | 105 | print c # [] |
paul@248 | 106 | |
paul@248 | 107 | k() |
paul@2 | 108 | |
paul@2 | 109 | def l(): |
paul@2 | 110 | global M |
paul@2 | 111 | M = [] |
paul@248 | 112 | print M # [] |
paul@248 | 113 | |
paul@248 | 114 | l() |
paul@248 | 115 | print M # [] |