Don't use the word "parse" for lexing operations.

Lexing converts source text into a token stream. Parsing converts a
token stream into AST fragments. This commit renames several lexing
operations that have "parse" in the name. I think these names have been
subtly confusing me for years.

This is just a `s/parse/lex/` on function names, with one exception:
`parse_stream_from_source_str` becomes `source_str_to_stream`, to make
it consistent with the existing `source_file_to_stream`. The commit also
moves that function's location in the file to be just above
`source_file_to_stream`.

The commit also cleans up a few comments along the way.

1 files changed, 2 insertions, 2 deletions

diff --git a/compiler/rustc_parse/src/lexer/mod.rs b/compiler/rustc_parse/src/lexer/mod.rs
index d3a6a033978..43f4963b27a 100644
--- a/compiler/rustc_parse/src/lexer/mod.rs
+++ b/compiler/rustc_parse/src/lexer/mod.rs
@@ -42,7 +42,7 @@ pub(crate) struct UnmatchedDelim {
     pub candidate_span: Option<Span>,
 }
 
-pub(crate) fn parse_token_trees<'psess, 'src>(
+pub(crate) fn lex_token_trees<'psess, 'src>(
     psess: &'psess ParseSess,
     mut src: &'src str,
     mut start_pos: BytePos,
@@ -66,7 +66,7 @@ pub(crate) fn parse_token_trees<'psess, 'src>(
         last_lifetime: None,
     };
     let (stream, res, unmatched_delims) =
-        tokentrees::TokenTreesReader::parse_all_token_trees(string_reader);
+        tokentrees::TokenTreesReader::lex_all_token_trees(string_reader);
     match res {
         Ok(()) if unmatched_delims.is_empty() => Ok(stream),
         _ => {