Use a separate node type for regex forms

This node type stores the pattern string, instead of using generic token nodes
that store java.util.Pattern objects.

java.util.Pattern instances cannot be compared using equals,
which would prevent comparison of sexprs generated by node/sexpr
that contain regex forms

Author: Chris Blom

src/rewrite_clj/node.clj

@@ -12,6 +12,7 @@
              protocols
              quote
              reader-macro
+             regex
              seq
              string
              token
@@ -57,6 +58,9 @@
    meta-node
    raw-meta-node]
 
+  [rewrite-clj.node.regex
+   regex-node]
+
   [rewrite-clj.node.reader-macro
    deref-node
    eval-node

src/rewrite_clj/node/regex.clj

@@ -0,0 +1,22 @@
+(ns ^:no-doc rewrite-clj.node.regex
+  (:require [rewrite-clj.node.protocols :as node]))
+
+
+;; ## Node
+
+(defrecord RegexNode [pattern]
+  rewrite-clj.node.protocols/Node
+  (tag [_] :regex)
+  (printable-only? [_] false)
+  (sexpr [_] (list 're-pattern pattern))
+  (length [_] 1)
+  (string [_] (str "#\"" pattern "\"")))
+
+(node/make-printable! RegexNode)
+
+;; ## Constructor
+
+(defn regex-node
+  "Create node representing a regex"
+  [pattern-string]
+  (->RegexNode pattern-string))

src/rewrite_clj/parser/core.clj

@@ -114,7 +114,7 @@
     nil (reader/throw-reader reader "Unexpected EOF.")
     \{ (node/set-node (parse-delim reader \}))
     \( (node/fn-node (parse-delim reader \)))
-    \" (parse-regex reader)
+    \" (node/regex-node (parse-regex reader))
     \^ (node/raw-meta-node (parse-printables reader :meta 2 true))
     \' (node/var-node (parse-printables reader :var 1 true))
     \= (node/eval-node (parse-printables reader :eval 1 true))

src/rewrite_clj/parser/string.clj

@@ -40,4 +40,4 @@
 (defn parse-regex
   [reader]
   (let [h (read-string-data reader)]
-    (node/token-node (re-pattern (string/join "\n" h)))))
+    (string/join "\n" h)))

test/rewrite_clj/parser_test.clj

@@ -112,15 +112,15 @@
 (tabular
   (fact "about parsing regular expressions"
     (let [n (p/parse-string ?s)]
-      (node/tag n) => :token
-      (class (node/sexpr n)) => java.util.regex.Pattern
-      (str (node/sexpr n)) => ?p))
+      (node/tag n) => :regex
+      (node/sexpr n) => ?p))
   ?s                 ?p
-  "#\"regex\""       "regex"
-  "#\"regex\\.\""    "regex\\."
-  "#\"[reg|k].x\""   "[reg|k].x"
-  "#\"a\\nb\""       "a\\nb"
-  "#\"a\nb\""        "a\nb")
+
+  "#\"regex\""       '(re-pattern "regex")
+  "#\"regex\\.\""    '(re-pattern "regex\\.")
+  "#\"[reg|k].x\""   '(re-pattern "[reg|k].x")
+  "#\"a\\nb\""       '(re-pattern "a\\nb")
+  "#\"a\nb\""        '(re-pattern "a\nb"))
 
 (tabular
   (fact "about parsing strings"