Move lexer to use regex instead of hand-rolled lexing

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

Cargo.lock

@@ -1,5 +1,14 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+[[package]]
+name = "aho-corasick"
+version = "0.7.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8716408b8bc624ed7f65d223ddb9ac2d044c0547b6fa4b0d554f3a9540496ada"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "doc-comment"
 version = "0.3.3"
@@ -18,12 +27,19 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3e2e65a1a2e43cfcb47a895c4c8b10d1f4a61097f9f254f183aee60cad9c651d"
 
+[[package]]
+name = "memchr"
+version = "2.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3728d817d99e5ac407411fa471ff9800a778d88a24685968b36824eaf4bee400"
+
 [[package]]
 name = "not-python"
 version = "0.1.0"
 dependencies = [
  "lazy_static",
  "maplit",
+ "regex",
  "snafu",
 ]
 
@@ -45,6 +61,24 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "regex"
+version = "1.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a6020f034922e3194c711b82a627453881bc4682166cabb07134a10c26ba7692"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+ "thread_local",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fe5bd57d1d7414c6b5ed48563a2c855d995ff777729dcd91c369ec7fea395ae"
+
 [[package]]
 name = "snafu"
 version = "0.6.6"
@@ -77,6 +111,15 @@ dependencies = [
  "unicode-xid",
 ]
 
+[[package]]
+name = "thread_local"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d40c6d1b69745a6ec6fb1ca717914848da4b44ae29d9b3080cbee91d72a69b14"
+dependencies = [
+ "lazy_static",
+]
+
 [[package]]
 name = "unicode-xid"
 version = "0.2.0"