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Pattern.compile/1 returns an {anchored, elements} tuple, but only find/3
used the flag - gsub/4, gsub_stateful/5, and gmatch/2 discarded it.
Because compile strips the leading ^, those entry points matched the
remaining pattern at every position, so string.gsub("xax", "^x", "Y")
returned "YaY", 2 instead of "Yax", 1, silently corrupting the common
leading-trim idiom s:gsub("^%s+", "").
Route gsub and gsub_stateful through an anchored branch that tries the
match only at position 0 and replaces at most once, mirroring PUC-Lua
str_gsub's anchor flag. An n of 0 still suppresses the replacement, and
an empty anchored match (e.g. ^a* on "bbb") replaces once at the start.
gmatch needed the opposite treatment: per Lua 5.3 (and PUC-Lua's
gmatch_aux, which never strips the caret), a leading ^ in gmatch is not
an anchor but an ordinary literal character - so recompile the pattern
keeping the caret literal instead of dropping it.
Expected values in the regression tests are verified against PUC-Lua
5.3.6.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01F3LBtzmXgAMHA8QiGPa5Ek
The standard Lua OOP idiom (T.__index = T) creates tables that contain
themselves. Both eval-boundary walks recursed into them forever,
growing memory without bound: Value.decode in decode: true mode and
Display.peek_table in decode: false mode.
The walk now terminates at the point of recurrence: decode leaves the
table's {:tref, id} reference there, mirroring how functions already
pass through as opaque references, and Display renders a :circular
peek. Shared non-cyclic references decode in full.
OTP 28's opacity checker false-positives on the MapSet the walkers capture in their entry closures (call_without_opaque on every MapSet call), failing CI. Specs on the private clauses don't appease it. A plain map with the ids as keys is the same structure MapSet wraps, so behavior is identical and there is no opaque type left to police.
fix(pattern): honour ^ anchor in gsub and literal caret in gmatch
Fix unbounded recursion on cyclic tables at the eval boundary
A valueless `return` followed by a comment before the block terminator (`elseif`/`else`/`end`/`until`) failed to parse with "Expected expression". `parse_return/1` peeked at the raw next token to detect an empty return; a comment token is not a terminator, so it fell through to `parse_expr_list` and choked on the comment. Comments are whitespace in Lua, so peek past them (`skip_comments/1`) when deciding whether the return is bare. The comment tokens are left in the stream so the block parser still collects them as orphaned/trailing comments. Real Lua 5.3 and Luerl both accept this; the idiom shows up in `if ... then return -- note \n elseif ...` style branches. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
fix(parser): allow comments between a bare return and its terminator
# Conflicts: # lib/lua/vm/display/table.ex # lib/lua/vm/stdlib/pattern.ex # test/lua/vm/cyclic_table_test.exs # test/lua/vm/stdlib/pattern_anchor_test.exs
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Hey,
We noticed that some expected lua behaviour regarding dates is not working as expected.
Changes:
os.time normalises out-of-range date-table fields the way C mktime does
(e.g. day = 0 is the last day of the previous month, month = 13 is
January of the next year) instead of raising a MatchError