Support local identifiers as macro names and in macro definitions

Macro names beginning with a ~ character will be prefixed with the
name of the most recently defined label, and local invocations inside
macro definition bodies will also expand correctly.

1 files changed, 11 insertions, 8 deletions

diff --git a/src/stages/syntactic.rs b/src/stages/syntactic.rs
index ff3a65a..674ab08 100644
--- a/src/stages/syntactic.rs
+++ b/src/stages/syntactic.rs
@@ -4,15 +4,15 @@ use std::path::PathBuf;
 
 
 pub fn parse_syntactic<P: Into<PathBuf>>(source_code: &str, path: Option<P>) -> Result<Vec<Tracked<SyntacticToken>>, Vec<Tracked<SyntacticError>>> {
-    parse_syntactic_from_tokeniser(Tokeniser::new(source_code, path))
+    parse_syntactic_from_tokeniser(Tokeniser::new(source_code, path), "")
 }
 
-fn parse_syntactic_from_tokeniser(mut t: Tokeniser) -> Result<Vec<Tracked<SyntacticToken>>, Vec<Tracked<SyntacticError>>> {
-    t.add_delimiters(&['@','&','%',';','{','}','(',')','[',']','#','~','"','\'']);
+fn parse_syntactic_from_tokeniser(mut t: Tokeniser, label_name: &str) -> Result<Vec<Tracked<SyntacticToken>>, Vec<Tracked<SyntacticError>>> {
+    t.add_delimiters(&['@','&','%',';','{','}','(',')','[',']','#','"','\'']);
     t.add_terminators(&[':']);
     let mut tokens = Vec::new();
     let mut errors = Vec::new();
-    let mut label_name = String::new();
+    let mut label_name = label_name.to_string();
 
     macro_rules! err {
         ($error:expr) => {{
@@ -70,12 +70,15 @@ fn parse_syntactic_from_tokeniser(mut t: Tokeniser) -> Result<Vec<Tracked<Syntac
                 }
             }
             '%' => {
-                let name = t.eat_token();
+                let mut name = t.eat_token();
+                if let Some(local) = name.strip_prefix('~') {
+                    name = format!("{label_name}/{local}");
+                }
                 let source = t.get_source();
                 t.mark_child();
                 if let Some(_) = t.track_until(is_any!(';')) {
                     let child = t.tokenise_child_span();
-                    match parse_body_from_tokeniser(child) {
+                    match parse_body_from_tokeniser(child, &label_name) {
                         Ok(body) => {
                             let name = Tracked::from(name, source);
                             let definition = SyntacticMacroDefinition { name, body };
@@ -161,11 +164,11 @@ fn parse_syntactic_from_tokeniser(mut t: Tokeniser) -> Result<Vec<Tracked<Syntac
 }
 
 
-fn parse_body_from_tokeniser(t: Tokeniser) -> Result<Vec<Tracked<SyntacticToken>>, Vec<Tracked<SyntacticError>>> {
+fn parse_body_from_tokeniser(t: Tokeniser, label_name: &str) -> Result<Vec<Tracked<SyntacticToken>>, Vec<Tracked<SyntacticError>>> {
     let mut tokens = Vec::new();
     let mut errors = Vec::new();
 
-    for token in parse_syntactic_from_tokeniser(t)? {
+    for token in parse_syntactic_from_tokeniser(t, label_name)? {
         match token.value {
             SyntacticToken::LabelDefinition(_) => {
                 let error = SyntacticError::LabelDefinitionInMacroDefinition;