better error print

src/interpreter/duck_interpreter.rs

@@ -10,7 +10,13 @@ pub fn main() {
     let mut content = String::new();
     f.read_to_string(&mut content)
         .unwrap_or_else(|_| panic!("Error in reading file {}", path));
-    let ast = build_ast(&content).unwrap();
+    let ast = match build_ast(&content) {
+        Ok(ast) => ast,
+        Err(e) => {
+            eprintln!("Error in parsing file {}: {}", path, e);
+            exit(1);
+        }
+    };
     let mut machine = Machine::new();
     let ret = machine.run(ast).expect("execution failed");
     exit(ret as i32);

src/parser/ast.rs

@@ -314,6 +314,9 @@ pub fn build_ast(content: &str) -> Result<Vec<Stat>, String> {
                         Rule::op_neg => "-".to_owned(),
                         Rule::op_not => "!".to_owned(),
                         Rule::op_index => "[]".to_owned(),
+                        Rule::string => "string".to_owned(),
+                        Rule::ascii_string => "ascii string".to_owned(),
+                        Rule::ascii_range => "ascii range".to_owned(),
                         Rule::WHITESPACE => "whitespace".to_owned(),
                         Rule::COMMENT => "comment".to_owned(),
                         Rule::EOI => "end of input".to_owned(),

src/parser/duck.pest

@@ -1,5 +1,8 @@
 alpha = { 'a'..'z' | 'A'..'Z' }
 digit = { '0'..'9' }
+ascii_range = { '\x00'..'\x7F' }
+ascii_char = ${ !("'") ~ ascii_range }
+ascii_string = ${ (!("\"") ~ ascii_range)* }
 
 WHITESPACE = _{ " " | "\n" | "\t" }
 COMMENT = _{ block_comment | line_comment }
@@ -8,11 +11,11 @@ block_comment = @{ "/*" ~ ((!("*/") ~ ANY) | block_comment)* ~ "*/" }
 
 args_call = { (expr ~ ("," ~ expr)*)? }
 call = { variable ~ "(" ~ args_call ~ ")" }
-string = @{ "\"" ~ (!("\"") ~ ANY)* ~ "\"" }
-char = @{ "'" ~ (!("'") ~ ANY) ~ "'" }
-variable = @ { (alpha) ~ (alpha | digit)* }
-number = @ { (digit)+ }
-boolean = @ { "true" | "false" }
+string = ${ "\"" ~ ascii_string ~ "\"" }
+char = ${ "'" ~ ascii_char ~ "'" }
+variable = ${ (alpha) ~ (alpha | digit)* }
+number = ${ (digit)+ }
+boolean = ${ "true" | "false" }
 
 op_add = { "+" }
 op_sub = { "-" }