New nodes: 'Regex Contains', 'Regex Replace', 'Regex Find', 'Regex Find All', and 'Regex Split' (#4045)

* Add a family of 5 regex nodes for string processing

* Fix unstaged change

node-graph/nodes/text/Cargo.toml

@@ -26,6 +26,7 @@ log = { workspace = true }
 serde_json = { workspace = true }
 convert_case = { workspace = true }
 titlecase = { workspace = true }
+fancy-regex = { workspace = true }
 unicode-segmentation = { workspace = true }
 
 # Optional workspace dependencies

node-graph/nodes/text/src/lib.rs

@@ -1,6 +1,7 @@
 mod font_cache;
 pub mod json;
 mod path_builder;
+pub mod regex;
 mod text_context;
 mod to_path;
 

node-graph/nodes/text/src/regex.rs

@@ -0,0 +1,201 @@
+use core_types::Ctx;
+use core_types::registry::types::SignedInteger;
+
+/// Checks whether the string contains a match for the given regular expression pattern. Optionally restricts the match to only the start and/or end of the string.
+#[node_macro::node(category("Text: Regex"))]
+fn regex_contains(
+	_: impl Ctx,
+	/// The string to search within.
+	string: String,
+	/// The regular expression pattern to search for.
+	pattern: String,
+	/// Match letters regardless of case.
+	case_insensitive: bool,
+	/// Make `^` and `$` match the start and end of each line, not just the whole string.
+	multiline: bool,
+	/// Only match if the pattern appears at the start of the string.
+	at_start: bool,
+	/// Only match if the pattern appears at the end of the string.
+	at_end: bool,
+) -> bool {
+	let flags = match (case_insensitive, multiline) {
+		(false, false) => "",
+		(true, false) => "(?i)",
+		(false, true) => "(?m)",
+		(true, true) => "(?im)",
+	};
+	let anchored_pattern = match (at_start, at_end) {
+		(true, true) => format!("{flags}\\A(?:{pattern})\\z"),
+		(true, false) => format!("{flags}\\A(?:{pattern})"),
+		(false, true) => format!("{flags}(?:{pattern})\\z"),
+		(false, false) => format!("{flags}{pattern}"),
+	};
+
+	let Ok(regex) = fancy_regex::Regex::new(&anchored_pattern) else {
+		log::error!("Invalid regex pattern: {pattern}");
+		return false;
+	};
+
+	regex.is_match(&string).unwrap_or(false)
+}
+
+/// Replaces matches of a regular expression pattern in the string. The replacement string can reference captures: `$0` for the whole match and `$1`, `$2`, etc. for capture groups.
+#[node_macro::node(category("Text: Regex"))]
+fn regex_replace(
+	_: impl Ctx,
+	string: String,
+	/// The regular expression pattern to search for.
+	pattern: String,
+	/// The replacement string. Use `$0` for the whole match and `$1`, `$2`, etc. for capture groups.
+	replacement: String,
+	/// Replace all matches. When disabled, only the first match is replaced.
+	#[default(true)]
+	replace_all: bool,
+	/// Match letters regardless of case.
+	case_insensitive: bool,
+	/// Make `^` and `$` match the start and end of each line, not just the whole string.
+	multiline: bool,
+) -> String {
+	let flags = match (case_insensitive, multiline) {
+		(false, false) => "",
+		(true, false) => "(?i)",
+		(false, true) => "(?m)",
+		(true, true) => "(?im)",
+	};
+	let full_pattern = format!("{flags}{pattern}");
+
+	let Ok(regex) = fancy_regex::Regex::new(&full_pattern) else {
+		log::warn!("Invalid regex pattern: {pattern}");
+		return string;
+	};
+
+	if replace_all {
+		regex.replace_all(&string, replacement.as_str()).into_owned()
+	} else {
+		regex.replace(&string, replacement.as_str()).into_owned()
+	}
+}
+
+/// Finds a regex match in the string and returns its components. The result is a list where the first element is the whole match (`$0`) and subsequent elements are the capture groups (`$1`, `$2`, etc., if any).
+///
+/// The match index selects which non-overlapping occurrence to return (0 for the first match). Returns an empty list if no match is found at the given index.
+#[node_macro::node(category(""))]
+fn regex_find(
+	_: impl Ctx,
+	/// The string to search within.
+	string: String,
+	/// The regular expression pattern to search for.
+	pattern: String,
+	/// Which non-overlapping occurrence of the pattern to return, starting from 0 for the first match. Negative indices count backwards from the last match.
+	match_index: SignedInteger,
+	/// Match letters regardless of case.
+	case_insensitive: bool,
+	/// Make `^` and `$` match the start and end of each line, not just the whole string.
+	multiline: bool,
+) -> Vec<String> {
+	if pattern.is_empty() {
+		return Vec::new();
+	}
+
+	let flags = match (case_insensitive, multiline) {
+		(false, false) => "",
+		(true, false) => "(?i)",
+		(false, true) => "(?m)",
+		(true, true) => "(?im)",
+	};
+	let full_pattern = format!("{flags}{pattern}");
+
+	let Ok(regex) = fancy_regex::Regex::new(&full_pattern) else {
+		log::error!("Invalid regex pattern: {pattern}");
+		return Vec::new();
+	};
+
+	// Collect all matches since we need to support negative indexing
+	let matches: Vec<_> = regex.captures_iter(&string).filter_map(|c| c.ok()).collect();
+
+	let match_index = match_index as i32;
+	let resolved_index = if match_index < 0 {
+		let from_end = (-match_index) as usize;
+		if from_end > matches.len() {
+			return Vec::new();
+		}
+		matches.len() - from_end
+	} else {
+		match_index as usize
+	};
+
+	let Some(captures) = matches.get(resolved_index) else {
+		return Vec::new();
+	};
+
+	// Index 0 is the whole match, 1+ are capture groups
+	(0..captures.len()).map(|i| captures.get(i).map_or(String::new(), |m| m.as_str().to_string())).collect()
+}
+
+/// Finds all non-overlapping matches of a regular expression pattern in the string, returning a list of the matched substrings.
+#[node_macro::node(category("Text: Regex"))]
+fn regex_find_all(
+	_: impl Ctx,
+	/// The string to search within.
+	string: String,
+	/// The regular expression pattern to search for.
+	pattern: String,
+	/// Match letters regardless of case.
+	case_insensitive: bool,
+	/// Make `^` and `$` match the start and end of each line, not just the whole string.
+	multiline: bool,
+) -> Vec<String> {
+	if pattern.is_empty() {
+		return Vec::new();
+	}
+
+	let flags = match (case_insensitive, multiline) {
+		(false, false) => "",
+		(true, false) => "(?i)",
+		(false, true) => "(?m)",
+		(true, true) => "(?im)",
+	};
+	let full_pattern = format!("{flags}{pattern}");
+
+	let Ok(regex) = fancy_regex::Regex::new(&full_pattern) else {
+		log::error!("Invalid regex pattern: {pattern}");
+		return Vec::new();
+	};
+
+	regex.find_iter(&string).filter_map(|m| m.ok()).map(|m| m.as_str().to_string()).collect()
+}
+
+/// Splits a string into a list of substrings pulled from between separator characters as matched by a regular expression.
+///
+/// For example, splitting "Three, two, one... LIFTOFF" with pattern `\W+` (non-word characters) produces `["Three", "two", "one", "LIFTOFF"]`.
+#[node_macro::node(category("Text: Regex"))]
+fn regex_split(
+	_: impl Ctx,
+	/// The string to split into substrings.
+	string: String,
+	/// The regular expression pattern to split on. Matches are consumed and not included in the output.
+	pattern: String,
+	/// Match letters regardless of case.
+	case_insensitive: bool,
+	/// Make `^` and `$` match the start and end of each line, not just the whole string.
+	multiline: bool,
+) -> Vec<String> {
+	if pattern.is_empty() {
+		return vec![string];
+	}
+
+	let flags = match (case_insensitive, multiline) {
+		(false, false) => "",
+		(true, false) => "(?i)",
+		(false, true) => "(?m)",
+		(true, true) => "(?im)",
+	};
+	let full_pattern = format!("{flags}{pattern}");
+
+	let Ok(regex) = fancy_regex::Regex::new(&full_pattern) else {
+		log::error!("Invalid regex pattern: {pattern}");
+		return vec![string];
+	};
+
+	regex.split(&string).filter_map(|s| s.ok()).map(|s| s.to_string()).collect()
+}