Extract params list parsing

src/syntax/ast.rs

@@ -11,11 +11,15 @@ pub enum TopLevelDeclaration {
 #[derive(Debug)]
 pub struct FunctionDeclaration {
     pub identifier: Box<String>,
+    pub params_list: Box<ParamsList>,
 }
 
 #[derive(Debug)]
 pub struct Block {}
 
+#[derive(Debug)]
+pub struct ParamsList {}
+
 #[derive(Debug)]
 pub enum Binding {
     Val(ValBinding),

src/syntax/block.rs

@@ -1,6 +1,6 @@
 use crate::{
+    error_handling::SyntaxError,
     lexic::token::{Token, TokenType},
-    syntax::{utils::expect_token_w, SyntaxResult},
 };
 
 use super::{ast::Block, utils::parse_token_type, ParseResult};
@@ -19,16 +19,24 @@ pub fn parse_block<'a>(tokens: &'a Vec<Token>, pos: usize) -> ParseResult<Block,
     current_pos = next_pos;
 
     // Parse closing brace
-    let (_closing_brace, next_pos) = match expect_token_w(
+    let (_closing_brace, next_pos) =
-        tokens,
+        match parse_token_type(tokens, current_pos, TokenType::RightBrace) {
-        current_pos,
+            ParseResult::Ok(t, next) => (t, next),
-        TokenType::RightBrace,
+            ParseResult::Err(err) => return ParseResult::Err(err),
-        "Expected a closing brace after the block body.".into(),
+            ParseResult::Mismatch(t) => {
-        opening_brace,
+                return ParseResult::Err(SyntaxError {
-    ) {
+                    reason: String::from("Expected a closing brace after the block body."),
-        Ok(t) => t,
+                    error_start: t.position,
-        Err(Some(SyntaxResult::Err(err))) => return ParseResult::Err(err),
+                    error_end: t.get_end_position(),
-        _ => panic!("parse_block: invalid state"),
+                });
+            }
+            ParseResult::Unmatched => {
+                return ParseResult::Err(SyntaxError {
+                    reason: String::from("Expected a closing brace after the block body."),
+                    error_start: opening_brace.position,
+                    error_end: opening_brace.get_end_position(),
+                });
+            }
         };
     current_pos = next_pos;
 

src/syntax/function_declaration.rs

@@ -1,5 +1,3 @@
-use std::thread::current;
-
 use crate::{
     error_handling::SyntaxError,
     lexic::token::{Token, TokenType},
@@ -7,10 +5,11 @@ use crate::{
 };
 
 use super::{
-    ast::{FunctionDeclaration, TopLevelDeclaration},
+    ast::{FunctionDeclaration, ParamsList},
     block::parse_block,
-    utils::{expect_token_w, parse_token_type, try_token_type},
+    params_list::parse_params_list,
-    ParseResult, SyntaxResult,
+    utils::{parse_token_type, try_token_type},
+    ParseResult,
 };
 
 pub fn try_parse<'a>(tokens: &'a Vec<Token>, pos: usize) -> ParseResult<FunctionDeclaration, ()> {
@@ -45,25 +44,19 @@ pub fn try_parse<'a>(tokens: &'a Vec<Token>, pos: usize) -> ParseResult<Function
     };
     current_pos = next_pos;
 
-    // TODO: Call function that parses a parameter list
+    let (params_list, next_pos) = match parse_params_list(tokens, current_pos) {
-    let (opening_paren, next_pos) =
+        ParseResult::Ok(params, next_pos) => (params, next_pos),
-        match parse_token_type(tokens, current_pos, TokenType::LeftParen) {
-            ParseResult::Ok(id, next) => (id, next),
         ParseResult::Err(err) => return ParseResult::Err(err),
         ParseResult::Mismatch(wrong_token) => {
             return ParseResult::Err(SyntaxError {
-                    reason: String::from(
+                reason: String::from("Expected an opening paren afted the function identifier."),
-                        "Expected an opening paren afted the function identifier.",
-                    ),
                 error_start: wrong_token.position,
                 error_end: wrong_token.get_end_position(),
             });
         }
         ParseResult::Unmatched => {
             return ParseResult::Err(SyntaxError {
-                    reason: String::from(
+                reason: String::from("Expected an opening paren afted the function identifier."),
-                        "Expected an opening paren afted the function identifier.",
-                    ),
                 error_start: identifier.position,
                 error_end: identifier.get_end_position(),
             });
@@ -71,27 +64,6 @@ pub fn try_parse<'a>(tokens: &'a Vec<Token>, pos: usize) -> ParseResult<Function
     };
     current_pos = next_pos;
 
-    let (closing_paren, next_pos) =
-        match parse_token_type(tokens, current_pos, TokenType::RightParen) {
-            ParseResult::Ok(id, next) => (id, next),
-            ParseResult::Err(err) => return ParseResult::Err(err),
-            ParseResult::Mismatch(wrong_token) => {
-                return ParseResult::Err(SyntaxError {
-                    reason: String::from("Expected a closing paren afted the function identifier."),
-                    error_start: wrong_token.position,
-                    error_end: wrong_token.get_end_position(),
-                });
-            }
-            ParseResult::Unmatched => {
-                return ParseResult::Err(SyntaxError {
-                    reason: String::from("Expected a closing paren afted the function identifier."),
-                    error_start: opening_paren.position,
-                    error_end: opening_paren.get_end_position(),
-                });
-            }
-        };
-    current_pos = next_pos;
-
     let (_block, next_pos) = match parse_block(tokens, current_pos) {
         ParseResult::Ok(block, next_pos) => (block, next_pos),
         ParseResult::Err(error) => {
@@ -107,8 +79,8 @@ pub fn try_parse<'a>(tokens: &'a Vec<Token>, pos: usize) -> ParseResult<Function
         ParseResult::Unmatched => {
             return ParseResult::Err(SyntaxError {
                 reason: String::from("Expected a block after the function declaration."),
-                error_start: closing_paren.position,
+                error_start: identifier.position,
-                error_end: closing_paren.get_end_position(),
+                error_end: identifier.get_end_position(),
             });
         }
     };
@@ -118,8 +90,9 @@ pub fn try_parse<'a>(tokens: &'a Vec<Token>, pos: usize) -> ParseResult<Function
     ParseResult::Ok(
         FunctionDeclaration {
             identifier: Box::new(identifier.value.clone()),
+            params_list: Box::new(params_list),
         },
-        next_pos,
+        current_pos,
     )
 }
 
@@ -212,7 +185,7 @@ mod tests {
             ParseResult::Err(err) => {
                 assert_eq!(
                     err.reason,
-                    "Expected a closing paren afted the function identifier."
+                    "Expected a closing paren after the function identifier."
                 );
                 assert_eq!(err.error_start, 7);
                 assert_eq!(err.error_end, 8);
@@ -226,7 +199,7 @@ mod tests {
             ParseResult::Err(err) => {
                 assert_eq!(
                     err.reason,
-                    "Expected a closing paren afted the function identifier."
+                    "Expected a closing paren after the function identifier."
                 );
                 assert_eq!(err.error_start, 6);
                 assert_eq!(err.error_end, 7);
@@ -294,8 +267,8 @@ mod tests {
                     err.reason,
                     "Expected a block after the function declaration."
                 );
-                assert_eq!(err.error_start, 7);
+                assert_eq!(err.error_start, 4);
-                assert_eq!(err.error_end, 8);
+                assert_eq!(err.error_end, 6);
             }
             _ => panic!("Expected an error: {:?}", fun_decl),
         }

src/syntax/mod.rs

@@ -1,11 +1,10 @@
-use std::f32::consts::E;
-
 use crate::error_handling::{MistiError, SyntaxError};
 
 mod binding;
 mod block;
 mod expression;
 mod function_declaration;
+mod params_list;
 mod utils;
 
 pub mod ast;

src/syntax/params_list.rs

@@ -0,0 +1,47 @@
+use crate::{
+    error_handling::SyntaxError,
+    lexic::token::{Token, TokenType},
+    syntax::utils::parse_token_type,
+};
+
+use super::{ast::ParamsList, ParseResult};
+
+pub fn parse_params_list<'a>(
+    tokens: &'a Vec<Token>,
+    pos: usize,
+) -> ParseResult<ParamsList, &Token> {
+    let mut current_pos = pos;
+
+    let (opening_paren, next_pos) =
+        match parse_token_type(tokens, current_pos, TokenType::LeftParen) {
+            ParseResult::Ok(t, next) => (t, next),
+            ParseResult::Err(err) => return ParseResult::Err(err),
+            ParseResult::Mismatch(t) => return ParseResult::Mismatch(t),
+            ParseResult::Unmatched => return ParseResult::Unmatched,
+        };
+    current_pos = next_pos;
+
+    // Parse closing paren
+    let (_closing_paren, next_pos) =
+        match parse_token_type(tokens, current_pos, TokenType::RightParen) {
+            ParseResult::Ok(t, next) => (t, next),
+            ParseResult::Err(err) => return ParseResult::Err(err),
+            ParseResult::Mismatch(t) => {
+                return ParseResult::Err(SyntaxError {
+                    reason: String::from("Expected a closing paren after the function identifier."),
+                    error_start: t.position,
+                    error_end: t.get_end_position(),
+                });
+            }
+            ParseResult::Unmatched => {
+                return ParseResult::Err(SyntaxError {
+                    reason: String::from("Expected a closing paren after the function identifier."),
+                    error_start: opening_paren.position,
+                    error_end: opening_paren.get_end_position(),
+                });
+            }
+        };
+    current_pos = next_pos;
+
+    ParseResult::Ok(ParamsList {}, current_pos)
+}

src/syntax/utils.rs

@@ -103,47 +103,3 @@ pub fn _try_operator_w<'a>(
         }))),
     }
 }
-
-/// Ignores all whitespace and newlines
-pub fn expect_token_w<'a>(
-    tokens: &'a Vec<Token>,
-    pos: usize,
-    token_type: TokenType,
-    error_message: String,
-    prev_token: &Token,
-) -> Result<(&'a Token, usize), Option<SyntaxResult>> {
-    let mut current_pos = pos;
-
-    // Ignore all whitespace and newlines
-    while let Some(t) = tokens.get(current_pos) {
-        if t.token_type == TokenType::INDENT
-            || t.token_type == TokenType::DEDENT
-            || t.token_type == TokenType::NewLine
-        {
-            current_pos += 1;
-        } else {
-            break;
-        }
-    }
-
-    match tokens.get(current_pos) {
-        Some(t) if t.token_type == token_type => Ok((t, current_pos + 1)),
-        Some(t) if t.token_type == TokenType::EOF || t.token_type == TokenType::NewLine => {
-            Err(Some(SyntaxResult::Err(SyntaxError {
-                reason: error_message,
-                error_start: prev_token.position,
-                error_end: prev_token.get_end_position(),
-            })))
-        }
-        Some(t) => Err(Some(SyntaxResult::Err(SyntaxError {
-            reason: error_message,
-            error_start: t.position,
-            error_end: t.get_end_position(),
-        }))),
-        None => Err(Some(SyntaxResult::Err(SyntaxError {
-            reason: error_message,
-            error_start: prev_token.position,
-            error_end: prev_token.get_end_position(),
-        }))),
-    }
-}