From 2481b7297c9e0b8edb4d2996e7411ac8e06db529 Mon Sep 17 00:00:00 2001
From: Araozu <faraoz@unsa.edu.pe>
Date: Fri, 8 Sep 2023 20:28:53 -0500
Subject: [PATCH] Codegen minimal function declaration

---
 src/codegen/function_declaration.rs | 35 +++++++++++++++++++++++++++++
 src/codegen/mod.rs                  |  1 +
 src/codegen/top_level_construct.rs  |  2 +-
 src/syntax/binding.rs               |  6 ++---
 src/syntax/function_declaration.rs  |  2 +-
 src/syntax/mod.rs                   |  3 ++-
 6 files changed, 43 insertions(+), 6 deletions(-)
 create mode 100644 src/codegen/function_declaration.rs

diff --git a/src/codegen/function_declaration.rs b/src/codegen/function_declaration.rs
new file mode 100644
index 0000000..01978bf
--- /dev/null
+++ b/src/codegen/function_declaration.rs
@@ -0,0 +1,35 @@
+use crate::syntax::ast::FunctionDeclaration;
+
+use super::Transpilable;
+
+impl Transpilable for FunctionDeclaration {
+    fn transpile(&self) -> String {
+        format!("function {}() {{}}", self.identifier)
+    }
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::{lexic::get_tokens, syntax::{construct_ast, ast::TopLevelConstruct}};
+
+
+    #[test]
+    fn should_transpile() {
+        let tokens = get_tokens(&String::from("fun id() {}")).unwrap();
+        let result = construct_ast(&tokens).unwrap();
+
+        let fun_dec = result.bindings.get(0).unwrap();
+
+        match fun_dec {
+            TopLevelConstruct::Binding(_) => panic!("Expected function declaration"),
+            TopLevelConstruct::FunctionDeclaration(fun_decl) => {
+                let transpiled = fun_decl.transpile();
+
+                assert_eq!("function id() {}", transpiled);
+            },
+        }
+    }
+}
+
diff --git a/src/codegen/mod.rs b/src/codegen/mod.rs
index a7927ae..71fcadf 100644
--- a/src/codegen/mod.rs
+++ b/src/codegen/mod.rs
@@ -4,6 +4,7 @@ mod binding;
 mod expression;
 mod module_ast;
 mod top_level_construct;
+mod function_declaration;
 
 /// Trait that the AST and its nodes implement to support transformation to PHP
 trait Transpilable {
diff --git a/src/codegen/top_level_construct.rs b/src/codegen/top_level_construct.rs
index caf77fb..487ccba 100644
--- a/src/codegen/top_level_construct.rs
+++ b/src/codegen/top_level_construct.rs
@@ -6,7 +6,7 @@ impl Transpilable for TopLevelConstruct {
     fn transpile(&self) -> String {
         match self {
             TopLevelConstruct::Binding(binding) => binding.transpile(),
-            TopLevelConstruct::FunctionDeclaration(_) => todo!(),
+            TopLevelConstruct::FunctionDeclaration(fun) => fun.transpile(),
         }
     }
 }
diff --git a/src/syntax/binding.rs b/src/syntax/binding.rs
index aa64e14..20264eb 100644
--- a/src/syntax/binding.rs
+++ b/src/syntax/binding.rs
@@ -120,9 +120,9 @@ pub fn try_parse<'a>(tokens: &'a Vec<Token>, pos: usize) -> Option<SyntaxResult>
         })
     };
 
-    Some(SyntaxResult::Ok(super::ast::TopLevelConstruct::Binding(
-        binding,
-    )))
+    Some(SyntaxResult::Ok(
+        super::ast::TopLevelConstruct::Binding(binding)
+    ))
 }
 
 /// Expects the token at `pos` to be of type `token_type`
diff --git a/src/syntax/function_declaration.rs b/src/syntax/function_declaration.rs
index cc362a4..122aea6 100644
--- a/src/syntax/function_declaration.rs
+++ b/src/syntax/function_declaration.rs
@@ -130,7 +130,7 @@ pub fn try_parse<'a>(tokens: &'a Vec<Token>, pos: usize) -> Option<SyntaxResult>
     current_pos += 1;
 
     // Parse closing brace
-    let closing_brace = match try_token_type(tokens, current_pos, TokenType::RightBrace) {
+    let _closing_brace = match try_token_type(tokens, current_pos, TokenType::RightBrace) {
         Result3::Ok(t) => t,
         Result3::Err(t) => {
             // The parser found a token, but it's not an opening brace
diff --git a/src/syntax/mod.rs b/src/syntax/mod.rs
index cdfa81c..00a4be0 100755
--- a/src/syntax/mod.rs
+++ b/src/syntax/mod.rs
@@ -8,7 +8,7 @@ mod utils;
 pub mod ast;
 
 use crate::lexic::token::Token;
-use ast::{Binding, ModuleAST};
+use ast::ModuleAST;
 
 use self::ast::TopLevelConstruct;
 
@@ -46,5 +46,6 @@ pub fn construct_ast<'a>(tokens: &'a Vec<Token>) -> Result<ModuleAST, MistiError
 
 fn next_construct<'a>(tokens: &'a Vec<Token>, current_pos: usize) -> SyntaxResult {
     None.or_else(|| binding::try_parse(tokens, current_pos))
+        .or_else(|| function_declaration::try_parse(tokens, current_pos))
         .unwrap_or_else(|| SyntaxResult::None)
 }