[Codegen] Minimal codegen for a Block

CHANGELOG.md

@@ -15,6 +15,7 @@
 - Watch mode
 - Formatter
 - Simple language server
+- Decide how to handle comments in the syntax (?)
 
 ## v0.0.10
 
@@ -24,8 +25,8 @@
 
 - [x] Hand-make CLI, remove clap
 - [x] Compile a single file
-- [ ] Display error messages during compilation instead of panicking
-- [ ] Improve errror messages
+- [x] Display error messages during compilation instead of panicking
+- [x] Improve error messages
 - [ ] Implement code generation for ast nodes implemented as of now
 
 

src/codegen/block.rs

@@ -0,0 +1,14 @@
+use crate::syntax::ast::Block;
+
+use super::Transpilable;
+
+impl Transpilable for Block {
+    fn transpile(&self) -> String {
+        // TODO: Handle indentation
+        self.statements
+            .iter()
+            .map(|x| x.transpile())
+            .collect::<Vec<_>>()
+            .join("\n")
+    }
+}

src/codegen/function_declaration.rs

@@ -4,7 +4,11 @@ use super::Transpilable;
 
 impl Transpilable for FunctionDeclaration {
     fn transpile(&self) -> String {
-        format!("function {}() {{}}", self.identifier)
+        format!(
+            "function {}() {{\n{}\n}}",
+            self.identifier,
+            self.block.transpile()
+        )
     }
 }
 

src/codegen/mod.rs

@@ -1,9 +1,11 @@
 use crate::syntax::ast::ModuleAST;
 
 mod binding;
+mod block;
 mod expression;
 mod function_declaration;
 mod module_ast;
+mod statement;
 mod top_level_construct;
 
 /// Trait that the AST and its nodes implement to support transformation to PHP

src/codegen/module_ast.rs

@@ -11,7 +11,7 @@ impl Transpilable for ModuleAST {
             .map(|binding| binding.transpile())
             .collect();
 
-        bindings_str.join("\n")
+        format!("<?php\n\n{}\n", bindings_str.join("\n"))
     }
 }
 

src/codegen/statement.rs

@@ -0,0 +1,9 @@
+use crate::syntax::ast::statement::Statement;
+
+use super::Transpilable;
+
+impl Transpilable for Statement {
+    fn transpile(&self) -> String {
+        String::from("// TODO (statement)")
+    }
+}

src/error_handling/syntax_error.rs

@@ -1,22 +1,29 @@
-use std::collections::VecDeque;
-
 use super::{PrintableError, SyntaxError};
+use std::collections::VecDeque;
 
 impl PrintableError for SyntaxError {
     fn get_error_str(&self, chars: &Vec<char>) -> String {
         let (line, before, length) = get_line(chars, self.error_start, self.error_end);
 
+        let line_number = get_line_number(chars, self.error_start);
+        let line_number_whitespace = " ".repeat(line_number.to_string().len());
+
         let whitespace = vec![' '; before].iter().collect::<String>();
         let indicator = vec!['^'; length].iter().collect::<String>();
+        let reason = &self.reason;
 
         format!(
-            "\n{}\n{}{}\n\n{}{}{}\n{}",
-            line, whitespace, indicator, "Syntax error at pos ", self.error_start, ":", self.reason
+            r#"
+{line_number_whitespace} |
+{line_number           } | {line}
+{line_number_whitespace} | {whitespace}{indicator}
+
+{reason} at line {line_number}:{before}"#,
         )
     }
 }
 
-/// Extracts a lin e of code
+/// Extracts a line of code
 ///
 /// - `chars`: Input where to extract the line from
 /// - `start_position`: Position where the erroneous code starts
@@ -90,6 +97,22 @@ fn get_line(
     )
 }
 
+fn get_line_number(chars: &Vec<char>, target_pos: usize) -> usize {
+    let mut count = 1;
+
+    for (pos, char) in chars.iter().enumerate() {
+        if pos >= target_pos {
+            break;
+        }
+
+        if *char == '\n' {
+            count += 1;
+        }
+    }
+
+    count
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/lexic/mod.rs

@@ -449,4 +449,12 @@ mod indentation_tests {
         assert_eq!(TokenType::DEDENT, tokens[8].token_type);
         assert_eq!(TokenType::EOF, tokens[9].token_type);
     }
+
+    #[test]
+    fn should_lex_comments() {
+        let input = String::from("// ??");
+        let tokens = get_tokens(&input).unwrap();
+
+        assert_eq!(TokenType::Comment, tokens[0].token_type);
+    }
 }

src/syntax/ast/mod.rs

@@ -18,6 +18,7 @@ pub enum TopLevelDeclaration {
 pub struct FunctionDeclaration {
     pub identifier: Box<String>,
     pub params_list: Box<ParamsList>,
+    pub block: Box<Block>,
 }
 
 #[derive(Debug)]

src/syntax/functions/function_declaration.rs

@@ -64,7 +64,7 @@ pub fn try_parse<'a>(tokens: &'a Vec<Token>, pos: usize) -> ParseResult<Function
     };
     current_pos = next_pos;
 
-    let (_block, next_pos) = match parse_block(tokens, current_pos) {
+    let (block, next_pos) = match parse_block(tokens, current_pos) {
         ParseResult::Ok(block, next_pos) => (block, next_pos),
         ParseResult::Err(error) => {
             return ParseResult::Err(error);
@@ -91,6 +91,7 @@ pub fn try_parse<'a>(tokens: &'a Vec<Token>, pos: usize) -> ParseResult<Function
         FunctionDeclaration {
             identifier: Box::new(identifier.value.clone()),
             params_list: Box::new(params_list),
+            block: Box::new(block),
         },
         current_pos,
     )