move all parsing related bits to a separate module

crates/ra_syntax/src/parsing.rs

@@ -0,0 +1,24 @@
+#[macro_use]
+mod token_set;
+mod builder;
+mod lexer;
+mod parser_impl;
+mod parser_api;
+mod reparsing;
+mod grammar;
+
+use crate::{
+    parsing::builder::GreenBuilder,
+    syntax_node::{GreenNode, SyntaxError},
+};
+
+pub use self::lexer::{tokenize, Token};
+
+pub(crate) use self::reparsing::incremental_reparse;
+
+pub(crate) fn parse_text(text: &str) -> (GreenNode, Vec<SyntaxError>) {
+    let tokens = tokenize(&text);
+    let (green, errors) =
+        parser_impl::parse_with(GreenBuilder::new(), text, &tokens, grammar::root);
+    (green, errors)
+}