printbr(T)
$\overset{a\downarrow b\rightarrow}{\left[\begin{array}{ccc} {T_{xx}}& {T_{xy}}& {T_{xz}}\\ {T_{yx}}& {T_{yy}}& {T_{yz}}\\ {T_{zx}}& {T_{zy}}& {T_{zz}}\end{array}\right]}$
GOOD
time: 0.674000ms
stack: size: 0

    writing apparently does


    printbr(T'_ij':prune()) assertEq(T'_ij':prune(), T)
    $\overset{i\downarrow j\rightarrow}{\left[\begin{array}{ccc} {T_{xx}}& {T_{xy}}& {T_{xz}}\\ {T_{yx}}& {T_{yy}}& {T_{yz}}\\ {T_{zx}}& {T_{zy}}& {T_{zz}}\end{array}\right]}$
    ${\overset{i\downarrow j\rightarrow}{\left[\begin{array}{ccc} {T_{xx}}& {T_{xy}}& {T_{xz}}\\ {T_{yx}}& {T_{yy}}& {T_{yz}}\\ {T_{zx}}& {T_{zy}}& {T_{zz}}\end{array}\right]}} = {\overset{a\downarrow b\rightarrow}{\left[\begin{array}{ccc} {T_{xx}}& {T_{xy}}& {T_{xz}}\\ {T_{yx}}& {T_{yy}}& {T_{yz}}\\ {T_{zx}}& {T_{zy}}& {T_{zz}}\end{array}\right]}}$
    GOOD
    time: 6.894000ms
    stack: size: 9
    • Init
    • Prune
    • Expand
    • Prune
    • Factor
    • Prune
    • Tidy
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    printbr(T'_xx':prune()) assertEq(T'_xx':prune(), T[1][1])
    ${T_{xx}}$
    ${{T_{xx}}} = {{T_{xx}}}$
    GOOD
    time: 4.359000ms
    stack: size: 2
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    printbr(T'_xy':prune()) assertEq(T'_xy':prune(), T[1][2])
    ${T_{xy}}$
    ${{T_{xy}}} = {{T_{xy}}}$
    GOOD
    time: 6.453000ms
    stack: size: 2
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    printbr(T'_xz':prune()) assertEq(T'_xz':prune(), T[1][3])
    ${T_{xz}}$
    ${{T_{xz}}} = {{T_{xz}}}$
    GOOD
    time: 3.063000ms
    stack: size: 2
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    printbr(T'_yx':prune()) assertEq(T'_yx':prune(), T[2][1])
    ${T_{yx}}$
    ${{T_{yx}}} = {{T_{yx}}}$
    GOOD
    time: 4.057000ms
    stack: size: 2
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    printbr(T'_yy':prune()) assertEq(T'_yy':prune(), T[2][2])
    ${T_{yy}}$
    ${{T_{yy}}} = {{T_{yy}}}$
    GOOD
    time: 2.848000ms
    stack: size: 2
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    printbr(T'_yz':prune()) assertEq(T'_yz':prune(), T[2][3])
    ${T_{yz}}$
    ${{T_{yz}}} = {{T_{yz}}}$
    GOOD
    time: 2.710000ms
    stack: size: 2
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    printbr(T'_zx':prune()) assertEq(T'_zx':prune(), T[3][1])
    ${T_{zx}}$
    ${{T_{zx}}} = {{T_{zx}}}$
    GOOD
    time: 4.114000ms
    stack: size: 2
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    printbr(T'_zy':prune()) assertEq(T'_zy':prune(), T[3][2])
    ${T_{zy}}$
    ${{T_{zy}}} = {{T_{zy}}}$
    GOOD
    time: 2.936000ms
    stack: size: 2
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    printbr(T'_zz':prune()) assertEq(T'_zz':prune(), T[3][3])
    ${T_{zz}}$
    ${{T_{zz}}} = {{T_{zz}}}$
    GOOD
    time: 3.855000ms
    stack: size: 2
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    printbr(T'_xp':prune()) assertEq(T'_xp':prune(), Tensor('_p', T[1][2], T[1][3]))
    $\overset{p\downarrow}{\left[\begin{matrix} {T_{xy}} \\ {T_{xz}}\end{matrix}\right]}$
    ${\overset{p\downarrow}{\left[\begin{matrix} {T_{xy}} \\ {T_{xz}}\end{matrix}\right]}} = {\overset{p\downarrow}{\left[\begin{matrix} {T_{xy}} \\ {T_{xz}}\end{matrix}\right]}}$
    GOOD
    time: 4.832000ms
    stack: size: 2
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    printbr(T'_yp':prune()) assertEq(T'_yp':prune(), Tensor('_p', T[2][2], T[2][3]))
    $\overset{p\downarrow}{\left[\begin{matrix} {T_{yy}} \\ {T_{yz}}\end{matrix}\right]}$
    ${\overset{p\downarrow}{\left[\begin{matrix} {T_{yy}} \\ {T_{yz}}\end{matrix}\right]}} = {\overset{p\downarrow}{\left[\begin{matrix} {T_{yy}} \\ {T_{yz}}\end{matrix}\right]}}$
    GOOD
    time: 4.153000ms
    stack: size: 2
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    printbr(T'_zp':prune()) assertEq(T'_zp':prune(), Tensor('_p', T[3][2], T[3][3]))
    $\overset{p\downarrow}{\left[\begin{matrix} {T_{zy}} \\ {T_{zz}}\end{matrix}\right]}$
    ${\overset{p\downarrow}{\left[\begin{matrix} {T_{zy}} \\ {T_{zz}}\end{matrix}\right]}} = {\overset{p\downarrow}{\left[\begin{matrix} {T_{zy}} \\ {T_{zz}}\end{matrix}\right]}}$
    GOOD
    time: 5.479000ms
    stack: size: 2
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    printbr(T'_px':prune()) assertEq(T'_px':prune(), Tensor('_p', T[2][1], T[3][1]))
    $\overset{p\downarrow}{\left[\begin{matrix} {T_{yx}} \\ {T_{zx}}\end{matrix}\right]}$
    ${\overset{p\downarrow}{\left[\begin{matrix} {T_{yx}} \\ {T_{zx}}\end{matrix}\right]}} = {\overset{p\downarrow}{\left[\begin{matrix} {T_{yx}} \\ {T_{zx}}\end{matrix}\right]}}$
    GOOD
    time: 6.947000ms
    stack: size: 2
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    printbr(T'_py':prune()) assertEq(T'_py':prune(), Tensor('_p', T[2][2], T[3][2]))
    $\overset{p\downarrow}{\left[\begin{matrix} {T_{yy}} \\ {T_{zy}}\end{matrix}\right]}$
    ${\overset{p\downarrow}{\left[\begin{matrix} {T_{yy}} \\ {T_{zy}}\end{matrix}\right]}} = {\overset{p\downarrow}{\left[\begin{matrix} {T_{yy}} \\ {T_{zy}}\end{matrix}\right]}}$
    GOOD
    time: 9.396000ms
    stack: size: 2
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    printbr(T'_pz':prune()) assertEq(T'_pz':prune(), Tensor('_p', T[2][3], T[3][3]))
    $\overset{p\downarrow}{\left[\begin{matrix} {T_{yz}} \\ {T_{zz}}\end{matrix}\right]}$
    ${\overset{p\downarrow}{\left[\begin{matrix} {T_{yz}} \\ {T_{zz}}\end{matrix}\right]}} = {\overset{p\downarrow}{\left[\begin{matrix} {T_{yz}} \\ {T_{zz}}\end{matrix}\right]}}$
    GOOD
    time: 5.012000ms
    stack: size: 2
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    printbr(T'_pq':prune()) assertEq(T'_pq':prune(), Tensor('_pq', {T[2][2], T[2][3]}, {T[3][2], T[3][3]}))
    $\overset{p\downarrow q\rightarrow}{\left[\begin{array}{cc} {T_{yy}}& {T_{yz}}\\ {T_{zy}}& {T_{zz}}\end{array}\right]}$
    ${\overset{p\downarrow q\rightarrow}{\left[\begin{array}{cc} {T_{yy}}& {T_{yz}}\\ {T_{zy}}& {T_{zz}}\end{array}\right]}} = {\overset{p\downarrow q\rightarrow}{\left[\begin{array}{cc} {T_{yy}}& {T_{yz}}\\ {T_{zy}}& {T_{zz}}\end{array}\right]}}$
    GOOD
    time: 3.078000ms
    stack: size: 2
    • Tensor.Ref:Prune:apply
    • Tensor.Ref:Prune:apply

    reading by __index doesn't work?
    I guess only writing by __index does for now
    but why bother read by __index when you can just use the __call operator with strings?
    printbr(T['_ij']) assertEq(T['_ij'], T)
    printbr(T['_xx']) assertEq(T['_xx'], T[1][1])
    printbr(T['_xy']) assertEq(T['_xy'], T[1][2])
    printbr(T['_xz']) assertEq(T['_xz'], T[1][3])
    printbr(T['_yx']) assertEq(T['_yx'], T[2][1])
    printbr(T['_yy']) assertEq(T['_yy'], T[2][2])
    printbr(T['_yz']) assertEq(T['_yz'], T[2][3])
    printbr(T['_zx']) assertEq(T['_zx'], T[3][1])
    printbr(T['_zy']) assertEq(T['_zy'], T[3][2])
    printbr(T['_zz']) assertEq(T['_zz'], T[3][3])
    printbr(T['_xp']) assertEq(T['_xp'])
    printbr(T['_yp']) assertEq(T['_yp'])
    printbr(T['_zp']) assertEq(T['_zp'])
    printbr(T['_px']) assertEq(T['_px'])
    printbr(T['_py']) assertEq(T['_py'])
    printbr(T['_pz']) assertEq(T['_pz'])
    printbr(T['_pq']) assertEq(T['_pq'])