add stdio module

crsn/src/asm/parse/parse_data.rs

@@ -85,9 +85,24 @@ pub fn parse_data_disp(tok: Sexp, pcx: &ParserContext) -> Result<DataDisp, CrsnE
 
             if s.starts_with('\'') && s.ends_with('\'') {
                 if s.chars().count() == 3 {
-                    return Ok(DataDisp::Immediate(s.chars().nth(1).unwrap() as u64));
+                    let ch = s.chars().nth(1).unwrap();
+                    if ch == '\'' {
+                        return Err(CrsnError::Parse("Use '\\'' for apos".into(), pos));
+                    }
+                    return Ok(DataDisp::Immediate(ch as u64));
                 } else if s.chars().count() == 4 && s.chars().nth(1).unwrap() == '\\' {
-                    return Ok(DataDisp::Immediate(s.chars().nth(2).unwrap() as u64));
+                    let ch = s.chars().nth(2).unwrap();
+                    let ch = match ch {
+                        '\\' => '\\',
+                        'n' => '\n',
+                        'r' => '\r',
+                        't' => '\t',
+                        '\'' => '\'',
+                        _ => {
+                            return Err(CrsnError::Parse(format!("Unknown escape sequence: {}", s).into(), pos));
+                        }
+                    };
+                    return Ok(DataDisp::Immediate(ch as u64));
                 } else {
                     return Err(CrsnError::Parse(format!("Invalid character literal synax {}", s).into(), pos));
                 }
@@ -96,7 +111,7 @@ pub fn parse_data_disp(tok: Sexp, pcx: &ParserContext) -> Result<DataDisp, CrsnE
             if let Some(reference) = s.strip_prefix('@') {
                 /* extension constants (pre-defined handles) */
                 for p in pcx.parsers {
-                    if let Some(val) = p.get_constant_value(&s) {
+                    if let Some(val) = p.get_constant_value(reference) {
                         return Ok(DataDisp::ImmObject(val));
                     }
                 }