refactor: simplify statement termination parsing

src/syntax/parsers/binding.rs

@@ -4,7 +4,7 @@ use crate::{
     syntax::{
         ast::{var_binding::VariableBinding, Expression},
         parseable::{Parseable, ParsingError, ParsingResult},
-        utils::{parse_token_type, try_operator},
+        utils::{parse_terminator, parse_token_type, try_operator},
     },
 };
 
@@ -127,23 +127,17 @@ impl<'a> Parseable<'a> for VariableBinding<'a> {
 
         // After the expression there should be a new line
         // to terminate the statement
-        match tokens.get(next_pos) {
-            Some(t) if t.token_type == TokenType::NewLine || t.token_type == TokenType::EOF => {
-                // continue
-            }
-            Some(t) => {
+        let next_pos = match parse_terminator(tokens, next_pos) {
+            Ok((_, next)) => next,
+            Err(ParsingError::Mismatch(t)) => {
                 return Err(ParsingError::Err(SyntaxError {
                     error_start: t.position,
                     error_end: t.get_end_position(),
                     reason: format!("Unexpected token `{}`, expected a new line", t.value),
                 }))
             }
-            _ => {
-                // this should never happen, the lexer always appends
-                // an EOF
-                unreachable!("got to the final of a token stream without finding EOF")
-            }
-        } 
+            _ => unreachable!(),
+        };
 
         let binding = VariableBinding {
             datatype,

src/syntax/parsers/module.rs

@@ -4,6 +4,7 @@ use crate::{
     syntax::{
         ast::{Expression, ModuleAST, ModuleMembers, Statement},
         parseable::{Parseable, ParsingError, ParsingResult},
+        utils::parse_terminator,
     },
 };
 
@@ -42,14 +43,9 @@ impl<'a> Parseable<'a> for ModuleAST<'a> {
                 Ok((prod, next_pos)) => {
                     // After a expression is parsed as an statement
                     // there should be a delimiter (new line or EOF)
-                    match tokens.get(next_pos) {
-                        Some(t)
-                            if t.token_type == TokenType::NewLine
-                                || t.token_type == TokenType::EOF =>
-                        {
-                            // continue
-                        }
-                        Some(t) => {
+                    let next_pos = match parse_terminator(tokens, next_pos) {
+                        Ok((_, next)) => next,
+                        Err(ParsingError::Mismatch(t)) => {
                             return Err(ParsingError::Err(SyntaxError {
                                 error_start: t.position,
                                 error_end: t.get_end_position(),
@@ -59,12 +55,8 @@ impl<'a> Parseable<'a> for ModuleAST<'a> {
                                 ),
                             }))
                         }
-                        _ => {
-                            // this should never happen, the lexer always appends
-                            // an EOF
-                            unreachable!("got to the final of a token stream without finding EOF")
-                        }
-                    }
+                        _ => unreachable!(),
+                    };
 
                     productions.push(ModuleMembers::Expr(prod));
                     current_pos = next_pos;
@@ -135,7 +127,7 @@ mod test {
 
         let (_, next) = ModuleAST::try_parse(&tokens, 0).unwrap();
 
-        assert_eq!(next, 1);
+        assert_eq!(next, 2);
     }
 
     #[test]

src/syntax/utils.rs

@@ -80,6 +80,39 @@ pub fn parse_token_type(
     }
 }
 
+/// Expects the token at `pos` to be a terminator (newline or eof)
+///
+/// Ignores indentation, newlines and comments.
+///
+/// Only returns: Ok or Unmatched.
+pub fn parse_terminator(
+    tokens: &Vec<Token>,
+    pos: usize,
+) -> ParsingResult<()> {
+    let mut current_pos = pos;
+
+    // Ignore all whitespace, newlines and semicolons
+    while let Some(t) = tokens.get(current_pos) {
+        if t.token_type == TokenType::INDENT
+            || t.token_type == TokenType::DEDENT
+            || t.token_type == TokenType::Comment
+            || t.token_type == TokenType::MultilineComment
+        {
+            current_pos += 1;
+        } else {
+            break;
+        }
+    }
+
+    match tokens.get(current_pos) {
+        Some(t) if t.token_type == TokenType::EOF || t.token_type == TokenType::NewLine => {
+            Ok(((), current_pos + 1))
+        }
+        Some(t) => Err(ParsingError::Mismatch(t)),
+        None => unreachable!("Stream of tokens finished before getting an EOF"),
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use crate::{