Start implementing a parser

Implement parsing text, variables and arguments. Start implementing
parsing filters. Stub out parsing tags.

Author: LilyFoote

Cargo.lock

@@ -10,6 +10,7 @@ crate-type = ["cdylib"]
 
 [dependencies]
 miette = { version = "7.2.0", features = ["fancy"] }
-pyo3 = "0.22.0"
+num-bigint = "0.4.6"
+pyo3 = { version = "0.22.0", features = ["num-bigint"] }
 thiserror = "1.0.64"
 unicode-xid = "0.2.6"

Cargo.toml

@@ -195,9 +195,9 @@ pub enum VariableTokenType {
 
 #[derive(Debug, PartialEq, Eq)]
 pub struct VariableToken<'t> {
-    token_type: VariableTokenType,
-    content: &'t str,
-    at: (usize, usize),
+    pub token_type: VariableTokenType,
+    pub content: &'t str,
+    pub at: (usize, usize),
 }
 
 enum Mode {

src/lex.rs

@@ -1 +1,2 @@
 mod lex;
+mod parse;