generalize parsing to allow extensions to add arbitrary syntax; add 'proc' keyword to introduce a routine.

crsn_screen/src/lib.rs

@@ -3,8 +3,8 @@ extern crate log;
 
 use crsn::asm::error::CrsnError;
 use crsn::asm::instr::Op;
-use crsn::asm::parse::arg_parser::ArgParser;
-use crsn::module::{CrsnExtension, ParseOpRes};
+use crsn::asm::parse::arg_parser::TokenParser;
+use crsn::module::{CrsnExtension, ParseRes};
 
 mod defs;
 mod parse;
@@ -24,7 +24,7 @@ impl CrsnExtension for ScreenOps {
         "screen"
     }
 
-    fn parse_op(&self, keyword: &str, args: ArgParser) -> Result<ParseOpRes<Op>, CrsnError> {
+    fn parse_op(&self, keyword: &str, args: TokenParser) -> Result<ParseRes<Op>, CrsnError> {
         parse::parse(keyword, args)
     }
 }

crsn_screen/src/parse.rs

@@ -1,13 +1,13 @@
 use crsn::asm::data::Rd;
 use crsn::asm::error::CrsnError;
 use crsn::asm::instr::Op;
-use crsn::asm::parse::arg_parser::ArgParser;
-use crsn::module::ParseOpRes;
+use crsn::asm::parse::arg_parser::TokenParser;
+use crsn::module::ParseRes;
 
 use crate::defs::ScreenOp;
 
-pub(crate) fn parse(keyword: &str, mut args: ArgParser) -> Result<ParseOpRes<Op>, CrsnError> {
-    Ok(ParseOpRes::ext(match keyword {
+pub(crate) fn parse(keyword: &str, mut args: TokenParser) -> Result<ParseRes<Op>, CrsnError> {
+    Ok(ParseRes::ext(match keyword {
         "sc-init" => {
             ScreenOp::ScreenInit {
                 width: args.next_rd()?,
@@ -41,7 +41,7 @@ pub(crate) fn parse(keyword: &str, mut args: ArgParser) -> Result<ParseOpRes<Op>
         }
 
         _other => {
-            return Ok(ParseOpRes::Unknown(args));
+            return Ok(ParseRes::Unknown(args));
         }
     }))
 }