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Graph/regex-and-template-parsing-semantic-leakage

AntiPattern

Regex Capture Staleness

regex-and-template-parsing-semantic-leakage

Regex and templating often leak unintended semantics when groups and delimiters are mis-specified: captured group text can persist across failed re-evaluations, trailing newlines create multiline output, and delimiter splitting misses edge positions, breaking downstream parsing and assertions.

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Updated6/24/2026

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30 linked nodes

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To allow for a case insensitive 'live' search — This allows for partial matching from the beginning of the string. Tension: you may need to further adapt the regular expression. Outcome: adapt the code as follows.

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Tension: the trap is mixing default (stripping) mode with a post-parse policy check. Outcome: parse AFTER the guard.

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Do expression evaluations in a single line

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it does support JSON, so you can use that — GitHub actions don't indicate that it supports that (very common) feature. Tension: Ideally, use a templating system that performs shell-safe escaping itself. Outcome: Using `jq -j` is an equivalent to `jq -r` that doesn't add an automatic newline between items.

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"ParameterName": "Delimiter", "ParameterValue": "\n". Tension: what is the terraform equivalent parameter for enabling "New line delimiter". Outcome: parameter_value = "\\n".

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Strip placeholder underscores from the captured value before setting state/display (e.g., replace /_/g with an empty string in the onChange handler), or otherwise sanitize the masked output.

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Use regex extraction and cast matched numbers to NUMERIC for ordering

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Tension: there's colon `:` syntax for that. Outcome: That works in tandem with variadic version of `unnest()` - note that I gave it two arguments.

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source is MongoDB and target is Redshift. Tension: I am unable to get the correct query. Outcome: tried using the regex to remove the string part in the format1.

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Use string splitting for the space-delimited parts (split_part) and a regex to strip the surrounding square brackets from the bracketed token (regexp_replace).

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use `Seqlelize.Op.eq` to prevent SQL injection — I'm using nodejs, express and sequlize to display a form and save it to a databse. Tension: or should some other technique (such as normalize) also be used? Outcome: Also is there something else I need to watch out for?

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Fix the regex escaping in importOrder (e.g., use \.(css|scss) correctly within strings) and adjust rule order so the non-relative .css/.scss matcher is applied to those imports last (e.g., exclude/route .*\.(css|scss)$ after the broader patterns).

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`{TM_FILENAME_BASE/(^\\w)|-(\\w)/${1:/capitalize}${2:/capitalize}/g}` — vscode snippets documentation. Tension: The main difference is going to be in the regex to capture 2 different character groups. Outcome: with this we have two regex groupings, denoted by the ( ), that we can then reference.

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a quote needs to be escaped using two quotes — You're using `CSVFormat.DEFAULT` which is based on RFC 4180. Tension: inside a quoted string a quote needs to be escaped. Outcome: the problem is not in your production code, nor in the library, but in your `expected` value.

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My current effort is `(?https://regex101.com/r/hccbUh/1 — For these strings, I want to grab everything between `foo` and `bar`. Tension: haven't found one that works. Outcome: Given this `(?https://regex101.com/r/IAQgB5/1.

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How can I avoid that and not match this `g`? — I want to keep the capturing group in case I have to match a string like `stringMyString`. Tension: I do need that `g` as group 1. Outcome: avoid that and not match this `g`.

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If you want to avoid that then you need a way to separate that initial line and capture its contents — The main issue to overcome here is that you are treating the first line of your CSV specially. Tension: its contents inform the processing of all the other lines. Outcome: here is where `filter()` comes in, and the fact that lambdas close over their context.

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Use `\r\n` rather than `\n`. — This Comment by dave_thompson_085 explains the issue. Tension: Your HTTP request is malformed.

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String[] parts = test.split("((?<=\\))\\s*|(?<=\\d{1,}\\.\\d{2} (DR|CR)))"); — for (String test: tests){. Tension: You could add the case "... or split for any white space preceded by a parenthesis". Outcome: Your regex could be written like this:.

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Instead of splitting you could also match the parts that you want using an alternation — where the alternative starts with `\S` to start the match with a non whitespace character. Tension: to prevent matching empty strings. Outcome: \d+(?:\.\d+)?\h*[DC]R|\S.*?(?=\h*\d+(?:\.\d+)?\h*[DC]R).

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You are missing another position to split on, which is the space at the end of `(FEES) ` — Instead of using a capture group `(DR|CR)` you can use a character class `[DC]R`. Tension: you can assert a digit to the right. Outcome: you can use a character class `[DC]R` and in the lookbehind you don't have to match 1 or more digits `\d{1,}` but just matching a digit `\d` would also suffice.

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Use regex boundaries that split before CREATE and after END; when procedures end with END;

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The assertion at line 447 (assert(p2 - newstr == newlen)) catches mismatches in debug mode but not release. — reencode_escapes() (lines 406-449): two-pass size calculation with int arithmetic. Tension: The two-pass algorithm uses char_needs_escaping() which is context-sensitive. Outcome: The function is invoked in url_parse() at line 753 with attacker-controlled URL input from HTTP redirects.

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The fix (commit ed0c7c7e) defines allowed = "-_.!~*'();:&=+$," and scans each character — The fix (commit ed0c7c7e) defines allowed = "-_.!~*'();:&=+$," and scans each character. Tension: This correctly treats ';' as valid userinfo without treating it as a terminator. Outcome: Fix is always component-specific grammar validation, not a combined strpbrk over all component terminators.

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Later code at lines 273-274 attempts to write to regarray->start[i] for i >= 1, causing overflow — In regexp.c lines 265-267 within match_regex. Tension: Only allocates 1 element. Outcome: regsize can reach 16 (when max_id is 15).

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Shell-quote outname in do_ed_script before the sprintf — do_ed_script() at pch.c:2399-2403. Tension: avoid shell interpretation entirely.

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deduplicated stream-json final result text. Tension: schema drift is scored instead of discarded. Outcome: added a Markdown fallback parser for `<finding>` blocks.

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Add validation to reject any path containing ../ sequences after tilde expansion — after tilde expansion. Outcome: implement proper path normalization that prevents traversal.

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Grep every exported function for call sites excluding its test file. — Checklist when a sophisticated system produces no measurable output. Tension: Code can lie by omission; live state can't. Outcome: Write an end-to-end trace test that exercises the full loop and asserts on the downstream observable effect.

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markdown code spans contain Greek letters. Tension: Three options, in order of preference:. Outcome: This produced a clean rebuild for me.

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