Implement define statements

demo/Cargo.lock

@@ -1739,9 +1739,9 @@ dependencies = [
 
 [[package]]
 name = "regex"
-version = "1.8.1"
+version = "1.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af83e617f331cc6ae2da5443c602dfa5af81e517212d9d611a5b3ba1777b5370"
+checksum = "81ca098a9821bd52d6b24fd8b10bd081f47d39c22778cafaa75a2857a62c6390"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -1750,9 +1750,9 @@ dependencies = [
 
 [[package]]
 name = "regex-syntax"
-version = "0.7.1"
+version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a5996294f19bd3aae0453a862ad728f60e6600695733dd5df01da90c54363a3c"
+checksum = "436b050e76ed2903236f032a59761c1eb99e1b0aead2c257922771dab1fc8c78"
 
 [[package]]
 name = "renrs"
@@ -1760,6 +1760,7 @@ version = "0.1.0"
 dependencies = [
  "pest",
  "pest_derive",
+ "regex",
 ]
 
 [[package]]

demo/demo.rpy

@@ -1,5 +1,6 @@
 # Control testing
-"Bob" "I will not say anything"
+"Bob" "I will not say anything, [foo]"
+define foo = "bar"
 if False:
     "Bob" "W-what? Why am I saying this?"
     if True:
@@ -11,4 +12,6 @@ if True:
     "Bob" "...cereal!"
     if False:
         "Bob" "But I actually hate it."
+        define bar = "potato"
+        define foo = bar
 "Bob sat on the bench."