refactor: don't concatenate tag in updateExpr

[samestep]

Description

I wrote this code in #984 but it's pointlessly confusing. This PR makes it a bit less confusing.

Checklist

• I have commented my code, particularly in hard-to-understand areas
• I have reviewed any generated registry diagram changes

[github-actions]

± Registry diff

📊 Performance

Key

Note that each bar component rounds up to the nearest 100ms, so each full bar is an overestimate by up to 400ms.

     0s   1s   2s   3s   4s   5s   6s   7s   8s   9s
     |    |    |    |    |    |    |    |    |    |
name ▝▀▀▀▀▀▀▀▀▀▀▀▚▄▄▄▄▄▄▄▄▄▞▀▀▀▀▀▀▀▀▀▀▀▀▚▄▄▄▄▄▄▄▄▄▖
      compilation labelling optimization rendering

Data

                                                                  0s   1s   2s   3s   4s   5s
                                                                  |    |    |    |    |    |
3d-projection-fake-3d-linear-algebra                              ▝▞▖
acquaintanceship-graph-simple-graph                               ▝▀▀▀▀▀▀▀▀▀▀▀▀▀▀▚▀▀▀▀▀▀▚
allShapes-allShapes                                               ▝▞▄▄▄▄
angle-equivalence-triangle-mesh-2d                                ▝▀▚▀▀▖
arrowheads-arrowheads                                             ▝▞▖
caffeine-structural-formula                                       ▝▀▀▞▖
call-directed-graph-directed-multigraph                           ▝▀▀▀▀▀▞▀▚
call-undirected-graph-pseudograph                                 ▝▀▀▀▀▞▚
center-shrink-circle-animation                                    ▝▞▖
circle-example-euclidean                                          ▝▀▞▖
closest-point-test-closest-point                                  ▝▀▀▀▀▀▚▚
collinear-euclidean                                               ▝▀▞▖
communications-network-one-way-links-graph-simple-directed-graph  ▝▀▀▀▚▀▖
complete-bipartite-graphs-simple-graph                            ▝▀▀▀▀▀▀▀▀▀▀▀▀▀▞▀▀▚
complete-graphs-simple-graph                                      ▝▀▀▀▀▀▀▀▀▚▀▀▖
computer-network-diagnostic-links-graph-pseudograph               ▝▀▀▀▀▚▚
computer-network-graph-simple-graph                               ▝▀▀▚▚
computer-network-multiple-links-graph-pseudograph                 ▝▀▀▀▚▀▚
computer-network-multiple-one-way-links-graph-directed-multigraph ▝▀▀▀▀▀▀▞▀▖
concyclic-pair-triangle-mesh-2d                                   ▝▚▚
congruent-triangles-euclidean                                     ▝▀▀▞▖
continuousmap-continuousmap                                       ▝▞▖
cotan-formula-triangle-mesh-2d                                    ▝▀▞▖
cube-graphs-simple-graph                                          ▝▀▀▀▀▀▀▀▀▀▀▞▀▖
cubic-bezier-cubic-bezier                                         ▝▚▀▚
cycle-graphs-simple-graph                                         ▝▀▀▀▀▀▞▀▖
glutamine-molecules-basic                                         ▝▀▚▚
half-adder-distinctive-shape                                      ▝▚▚
halfedge-mesh-triangle-mesh-2d                                    ▝▀▞▖
hybrid-topology-graph-simple-graph                                ▝▀▀▞▖
hypercube-network-graph-simple-graph                              ▝▀▀▀▀▞▖
hypergraph-hypergraph                                             ▝▀▀▚▀▀▀▀▀▀▀▀▖
incenter-triangle-euclidean                                       ▝▀▞▖
influence-graph-simple-directed-graph                             ▝▀▚▚
jobs-trained-matching-graph-simple-graph                          ▝▀▀▀▞▚
jobs-trained-no-matching-graph-simple-graph                       ▝▀▀▚▚
lagrange-bases-lagrange-bases                                     ▝▞▖
linear-array-graph-simple-graph                                   ▝▀▞▖
lines-around-rect-rect-line-dist                                  ▝▚▚
matrix-matrix-addition-matrix-ops                                 ▝▚▚
matrix-matrix-division-elementwise-matrix-ops                     ▝▚▚
matrix-matrix-multiplication-elementwise-matrix-ops               ▝▚▚
matrix-matrix-multiplication-matrix-ops                           ▝▚▚
matrix-matrix-subtraction-matrix-ops                              ▝▚▚
matrix-transpose-matrix-ops                                       ▝▚▚
matrix-vector-left-multiplication-matrix-ops                      ▝▚▚
matrix-vector-right-multiplication-matrix-ops                     ▝▚▚
mesh-network-graph-simple-graph                                   ▝▀▀▀▀▀▀▀▀▀▀▀▀▀▞▀▀▀▀▀▀▀▀▀▀▖
midsegment-triangles-euclidean                                    ▝▀▞▖
mobius-mobius                                                     ▝▞▖
module-dependency-graph-simple-directed-graph                     ▝▀▀▚▀▖
niche-overlap-graph-simple-graph                                  ▝▀▀▀▀▞▖
nitricacid-lewis                                                  ▝▀▚▀▚
non-convex-non-convex                                             ▝▚▚
one-water-molecule-atoms-and-bonds                                ▝▞▖
parallel-lines-euclidean                                          ▝▚▚
persistent-homology-persistent-homology                           ▝▀▚▀▀▀▀▀▀▀▚
points-around-line-shape-distance                                 ▝▀▞▖
points-around-polyline-shape-distance                             ▝▀▚▚
points-around-star-shape-distance                                 ▝▀▀▚▚
precedence-graph-simple-directed-graph                            ▝▀▀▚▚
protein-interaction-graph-simple-graph                            ▝▀▀▀▀▀▚▀▀▚
quaternion-group-group-theory-cayley-graph                        ▝▀▚▚
quaternion-group-group-theory-multiplication-table                ▝▀▀▚▞▖
relative-orientation-triangle-mesh-2d                             ▝▚▚
ring-topology-graph-simple-graph                                  ▝▀▞▖
round-robin-graph-simple-directed-graph                           ▝▀▀▀▀▞▖
scalar-vector-division-matrix-ops                                 ▝▞▖
scalar-vector-left-multiplication-matrix-ops                      ▝▚▚
scalar-vector-right-multiplication-matrix-ops                     ▝▞▖
siggraph-teaser-euclidean-teaser                                  ▝▀▞▖
star-topology-graph-simple-graph                                  ▝▀▚▚
tree-tree                                                         ▝▚▚
tree-venn                                                         ▝▀▚▚
tree-venn-3d                                                      ▝▀▞▄▄▄
triangle-centers-triangle-mesh-2d                                 ▝▚▚
two-triangles-triangle-mesh-3d                                    ▝▚▚
two-vectors-perp-vectors-dashed                                   ▝▞▖
union-graph-simple-graph                                          ▝▀▀▞▖
vector-vector-addition-matrix-ops                                 ▝▚▚
vector-vector-division-elementwise-matrix-ops                     ▝▞▖
vector-vector-multiplication-elementwise-matrix-ops               ▝▚▚
vector-vector-outerproduct-matrix-ops                             ▝▚▚
vector-vector-subtraction-matrix-ops                              ▝▞▖
vector-wedge-exterior-algebra                                     ▝▞▖
wet-floor-atoms-and-bonds                                         ▝▚▀▖
wheel-graphs-simple-graph                                         ▝▀▀▀▀▀▀▀▀▞▀▚
word-cloud-example-word-cloud                                     ▝▀▞▖
wos-laplace-estimator-walk-on-spheres                             ▝▀▞▖
wos-nested-estimator-walk-on-spheres                              ▝▀▀▚▀▚
wos-offcenter-estimator-walk-on-spheres                           ▝▀▞▚
wos-poisson-estimator-walk-on-spheres                             ▝▀▞▚