fix: stabilize runtime benches and GLR tablegen EOF handling

[EffortlessSteven]

Scope

• Address GLR/benchmark-tail surface issues from remaining advisory failures.
• Stabilize by fixing missing token patterns and EOF handling assumptions.

This is the third code-surface PR in the two-track release rollout.

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⚙️ Run configuration

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📥 Commits

Reviewing files that changed from the base of the PR and between a539d1b and 3127df6.

📒 Files selected for processing (3)

• tablegen/src/generate.rs
• tablegen/src/validation.rs
• tablegen/tests/test_small_table.rs

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/glr-and-bench-stability

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[github-actions]

Benchmark Results

Benchmark Comparison

Benchmark	Baseline	Current	Change	Status
lexer_arithmetic_expression	80,324 ns	80,363 ns	+0.0%	✓ No change
lexer_complex_program	458,457 ns	466,456 ns	+1.7%	✓ No change
lexer_long_expression	89,700 ns	90,012 ns	+0.3%	✓ No change
lexer_long_identifier	76,429 ns	76,275 ns	-0.2%	✓ No change
lexer_many_tokens	187,726 ns	192,723 ns	+2.7%	✓ No change
lexer_nested_expression	86,818 ns	87,067 ns	+0.3%	✓ No change
lexer_simple_program	260,073 ns	262,603 ns	+1.0%	✓ No change
parse_deeply_nested	85,785 ns	82,860 ns	-3.4%	✓ No change
parse_highly_ambiguous	154,503 ns	150,611 ns	-2.5%	✓ No change
parse_maximum_forks	128,412 ns	125,809 ns	-2.0%	✓ No change
parse_simple_expression	73,049 ns	70,986 ns	-2.8%	✓ No change

✅ No performance regressions detected.

[github-actions]

✅ Performance Report

No Significant Regressions

Benchmark Comparison (click to expand)

group                                         pr-base                                pr-head
-----                                         -------                                -------
first_follow/compute/expression               1.00      6.2±0.13µs        ? ?/sec    1.00      6.2±0.10µs        ? ?/sec
first_follow/compute/nonnullable              1.00   924.5±11.97ns        ? ?/sec    1.01   931.8±20.03ns        ? ?/sec
first_follow/compute/nullable                 1.00    975.2±5.96ns        ? ?/sec    1.02    990.5±4.57ns        ? ?/sec
glr-perf-snapshot/small-parse                 1.00    275.3±6.50ns  3.5 MElem/sec    1.01   277.1±17.27ns  3.4 MElem/sec
lr1_automaton_build/full_build/expression     1.01    163.0±4.10µs        ? ?/sec    1.00    161.6±0.74µs        ? ?/sec
lr1_automaton_build/full_build/nonnullable    1.02      5.6±0.03µs        ? ?/sec    1.00      5.5±0.06µs        ? ?/sec
lr1_automaton_build/full_build/nullable       1.02      5.9±0.46µs        ? ?/sec    1.00      5.8±0.12µs        ? ?/sec
parse_deeply_nested                           1.00     85.5±1.12µs        ? ?/sec    1.02     87.0±3.70µs        ? ?/sec
parse_highly_ambiguous                        1.00    157.5±3.53µs        ? ?/sec    1.02    160.9±0.83µs        ? ?/sec
parse_maximum_forks                           1.00    132.0±2.18µs        ? ?/sec    1.01    133.2±3.25µs        ? ?/sec
parse_simple_expression                       1.00     71.7±1.43µs        ? ?/sec    1.00     71.7±1.41µs        ? ?/sec

How to interpret these results

• Faster/Slower: Shows performance change relative to base branch
• x N faster/slower: Multiplier of performance change
• ⚠️ Regressions >5% should be investigated before merging
• Small variations (<3%) are normal and may be noise
• See docs/PERFORMANCE_BASELINE.md for critical path thresholds

Critical Paths (from baseline):

• Python 1000 lines: 62.4µs (alert if >65µs)
• GLR fork operation: 73ns (alert if >77ns)
• Expression (100 ops): 11ns (alert if >12ns)

---

Benchmarks run with quick mode for CI. For detailed analysis, run cargo bench locally.

[github-actions]

✅ Performance Report

No Significant Regressions

Benchmark Comparison (click to expand)

Unable to generate performance report

How to interpret these results

• Faster/Slower: Shows performance change relative to base branch
• x N faster/slower: Multiplier of performance change
• ⚠️ Regressions >5% should be investigated before merging
• Small variations (<3%) are normal and may be noise
• See docs/PERFORMANCE_BASELINE.md for critical path thresholds

Critical Paths (from baseline):

• Python 1000 lines: 62.4µs (alert if >65µs)
• GLR fork operation: 73ns (alert if >77ns)
• Expression (100 ops): 11ns (alert if >12ns)

---

Benchmarks run with quick mode for CI. For detailed analysis, run cargo bench locally.

[github-actions]

✅ Performance Report

No Significant Regressions

Benchmark Comparison (click to expand)

group                                         pr-base                                pr-head
-----                                         -------                                -------
first_follow/compute/expression               1.01      6.1±0.07µs        ? ?/sec    1.00      6.0±0.10µs        ? ?/sec
first_follow/compute/nonnullable              1.02    927.1±7.49ns        ? ?/sec    1.00   908.2±12.28ns        ? ?/sec
first_follow/compute/nullable                 1.02   1045.4±8.24ns        ? ?/sec    1.00  1020.0±12.23ns        ? ?/sec
glr-perf-snapshot/small-parse                 1.00   301.4±28.34ns  3.2 MElem/sec    1.02   307.7±18.75ns  3.1 MElem/sec
lr1_automaton_build/full_build/expression     1.02    174.5±5.16µs        ? ?/sec    1.00    171.6±2.69µs        ? ?/sec
lr1_automaton_build/full_build/nonnullable    1.03      5.8±0.13µs        ? ?/sec    1.00      5.7±0.12µs        ? ?/sec
lr1_automaton_build/full_build/nullable       1.00      6.4±0.12µs        ? ?/sec    1.01      6.4±0.11µs        ? ?/sec
parse_deeply_nested                           1.00     88.2±1.65µs        ? ?/sec    1.00     88.3±1.47µs        ? ?/sec
parse_highly_ambiguous                        1.00    155.3±2.53µs        ? ?/sec    1.02    157.8±5.95µs        ? ?/sec
parse_maximum_forks                           1.00    131.5±2.24µs        ? ?/sec    1.01    132.2±1.58µs        ? ?/sec
parse_simple_expression                       1.00     75.0±1.11µs        ? ?/sec    1.00     75.3±1.28µs        ? ?/sec

How to interpret these results

• Faster/Slower: Shows performance change relative to base branch
• x N faster/slower: Multiplier of performance change
• ⚠️ Regressions >5% should be investigated before merging
• Small variations (<3%) are normal and may be noise
• See docs/PERFORMANCE_BASELINE.md for critical path thresholds

Critical Paths (from baseline):

• Python 1000 lines: 62.4µs (alert if >65µs)
• GLR fork operation: 73ns (alert if >77ns)
• Expression (100 ops): 11ns (alert if >12ns)

---

Benchmarks run with quick mode for CI. For detailed analysis, run cargo bench locally.

[github-actions]

✅ Performance Report

No Significant Regressions

Benchmark Comparison (click to expand)

group                                         pr-base                                pr-head
-----                                         -------                                -------
first_follow/compute/expression               1.00      6.0±0.03µs        ? ?/sec    1.00      6.0±0.04µs        ? ?/sec
first_follow/compute/nonnullable              1.00    898.6±8.38ns        ? ?/sec    1.02   915.5±19.05ns        ? ?/sec
first_follow/compute/nullable                 1.00   1003.7±7.57ns        ? ?/sec    1.00  1002.9±17.59ns        ? ?/sec
glr-perf-snapshot/small-parse                 1.00   300.2±18.27ns  3.2 MElem/sec    1.01   302.3±13.28ns  3.2 MElem/sec
lr1_automaton_build/full_build/expression     1.03    172.2±4.03µs        ? ?/sec    1.00    166.5±3.19µs        ? ?/sec
lr1_automaton_build/full_build/nonnullable    1.05      5.9±0.12µs        ? ?/sec    1.00      5.6±0.11µs        ? ?/sec
lr1_automaton_build/full_build/nullable       1.03      6.4±0.14µs        ? ?/sec    1.00      6.2±0.10µs        ? ?/sec
parse_deeply_nested                           1.02     89.3±0.91µs        ? ?/sec    1.00     87.7±0.80µs        ? ?/sec
parse_highly_ambiguous                        1.03    160.6±3.27µs        ? ?/sec    1.00    155.7±1.88µs        ? ?/sec
parse_maximum_forks                           1.00    132.8±1.17µs        ? ?/sec    1.00    132.1±1.28µs        ? ?/sec
parse_simple_expression                       1.01     75.4±0.91µs        ? ?/sec    1.00     74.6±1.13µs        ? ?/sec

How to interpret these results

• Faster/Slower: Shows performance change relative to base branch
• x N faster/slower: Multiplier of performance change
• ⚠️ Regressions >5% should be investigated before merging
• Small variations (<3%) are normal and may be noise
• See docs/PERFORMANCE_BASELINE.md for critical path thresholds

Critical Paths (from baseline):

• Python 1000 lines: 62.4µs (alert if >65µs)
• GLR fork operation: 73ns (alert if >77ns)
• Expression (100 ops): 11ns (alert if >12ns)

---

Benchmarks run with quick mode for CI. For detailed analysis, run cargo bench locally.