From 846adfdbb0931b9bda93cf38383103b44d7bd62b Mon Sep 17 00:00:00 2001
From: EuAndreh <eu@euandre.org>
Date: Sun, 20 Jul 2025 09:31:16 -0300
Subject: Add initial support for caret and dollar metacharacters

---
 src/paca.mjs | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 55 insertions(+), 4 deletions(-)

(limited to 'src')

diff --git a/src/paca.mjs b/src/paca.mjs
index 4a85067..21a28e8 100644
--- a/src/paca.mjs
+++ b/src/paca.mjs
@@ -15,7 +15,7 @@ const ConcatStep = {
 	CLASS:     "class",
 };
 
-const nonConcatOperators = new Set(["*", "+", "?", "|", ")", "$"]);
+const nonConcatOperators = new Set(["*", "+", "?", "|", ")"]);
 
 const shouldConcat = (char, next) =>
 	next !== undefined &&
@@ -24,7 +24,7 @@ const shouldConcat = (char, next) =>
 	char !== "{" &&
 	!nonConcatOperators.has(next);
 
-const operatorChars = new Set([...nonConcatOperators, "("]);
+const operatorChars = new Set([...nonConcatOperators, "(", "$"]);
 const isOperator = char =>
 	operatorChars.has(char);
 
@@ -301,7 +301,10 @@ const ANCHOR_FNS = {
 				),
 			})
 			: {
-				out: out.concat({ operator: "caret" }),
+				out: out.concat([
+					{ meta: "^" },
+					{ operator: "concat" },
+				]),
 				state,
 				context,
 			},
@@ -316,7 +319,7 @@ const ANCHOR_FNS = {
 				),
 			})
 			: {
-				out: out.concat({ operator: "dollar" }),
+				out: out.concat([{ meta: "$" }]),
 				state,
 				context,
 			},
@@ -693,6 +696,52 @@ const wildcard = (_edge, id) => {
 	};
 };
 
+const caret = (_edge, id) => {
+	const start = id + 0;
+	const end   = id + 1;
+	return {
+		start,
+		end,
+		nodes: {
+			[start]: {
+				direct:      [],
+				transitions: {},
+				meta: {
+					op: "caret",
+					to: end,
+				},
+			},
+			[end]: {
+				direct:      [],
+				transitions: {},
+			},
+		},
+	};
+};
+
+const dollar = (_edge, id) => {
+	const start = id + 0;
+	const end   = id + 1;
+	return {
+		start,
+		end,
+		nodes: {
+			[start]: {
+				direct:      [],
+				transitions: {},
+				meta: {
+					op: "dollar",
+					to: end,
+				},
+			},
+			[end]: {
+				direct:      [],
+				transitions: {},
+			},
+		},
+	};
+};
+
 const OPERATORS_FNS = ({
 	zeroOrMoreFn = zeroOrMore,
 	oneOrMoreFn  = oneOrMore,
@@ -717,6 +766,8 @@ const OPERATORS = OPERATORS_FNS();
 const METACHARACTERS_FNS = {
 	"class": characterClass,
 	".":     wildcard,
+	"^":     caret,
+	"$":     dollar,
 };
 
 const baseNFA = (token, id) => (
-- 
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