From 277272e2b7a130bfe7a56a734c4a51d0445ef769 Mon Sep 17 00:00:00 2001
From: Garrit Franke <garrit@slashdev.space>
Date: Sun, 14 Feb 2021 21:16:45 +0100
Subject: [PATCH] feat: struct initialization

---
 src/generator/c.rs      |  2 ++
 src/generator/js.rs     | 21 +++++++++++++++++++++
 src/parser/node_type.rs |  1 +
 src/parser/rules.rs     | 42 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 66 insertions(+)

diff --git a/src/generator/c.rs b/src/generator/c.rs
index e108280..09b8f68 100644
--- a/src/generator/c.rs
+++ b/src/generator/c.rs
@@ -125,6 +125,7 @@ fn generate_expression(expr: Expression) -> String {
         Expression::Array(els) => generate_array(els),
         Expression::ArrayAccess(name, expr) => generate_array_access(name, *expr),
         Expression::BinOp(left, op, right) => generate_bin_op(*left, op, *right),
+        Expression::StructInitialization(_, _) => todo!(),
     }
 }
 
@@ -217,6 +218,7 @@ fn generate_function_call(func: String, args: Vec<Expression>) -> String {
             Expression::Str(s) | Expression::Variable(s) => s,
             Expression::Array(_) => todo!(),
             Expression::BinOp(left, op, right) => generate_bin_op(*left, op, *right),
+            Expression::StructInitialization(_, _) => todo!(),
         })
         .collect::<Vec<String>>()
         .join(",");
diff --git a/src/generator/js.rs b/src/generator/js.rs
index cf49194..58eb855 100644
--- a/src/generator/js.rs
+++ b/src/generator/js.rs
@@ -15,6 +15,7 @@
  */
 use crate::generator::Generator;
 use crate::parser::node_type::*;
+use std::collections::HashMap;
 
 pub struct JsGenerator;
 
@@ -116,6 +117,9 @@ fn generate_expression(expr: Expression) -> String {
         Expression::Array(els) => generate_array(els),
         Expression::ArrayAccess(name, expr) => generate_array_access(name, *expr),
         Expression::BinOp(left, op, right) => generate_bin_op(*left, op, *right),
+        Expression::StructInitialization(name, fields) => {
+            generate_struct_initialization(name, fields)
+        }
     }
 }
 
@@ -224,6 +228,9 @@ fn generate_function_call(func: String, args: Vec<Expression>) -> String {
             Expression::Str(s) | Expression::Variable(s) => s,
             Expression::Array(elements) => generate_array(elements),
             Expression::BinOp(left, op, right) => generate_bin_op(*left, op, *right),
+            Expression::StructInitialization(name, fields) => {
+                generate_struct_initialization(name, fields)
+            }
         })
         .collect::<Vec<String>>()
         .join(",");
@@ -265,6 +272,20 @@ fn generate_bin_op(left: Expression, op: BinOp, right: Expression) -> String {
     )
 }
 
+fn generate_struct_initialization(
+    _name: String,
+    fields: HashMap<String, Box<Expression>>,
+) -> String {
+    let mut out_str = "{".to_string();
+    for (key, value) in fields {
+        out_str += &format!("{}: {},", key, generate_expression(*value));
+    }
+
+    out_str += "}";
+
+    out_str.into()
+}
+
 fn generate_assign(name: Expression, expr: Expression) -> String {
     format!(
         "{} = {}",
diff --git a/src/parser/node_type.rs b/src/parser/node_type.rs
index 13a2c02..39a755d 100644
--- a/src/parser/node_type.rs
+++ b/src/parser/node_type.rs
@@ -112,6 +112,7 @@ pub enum Expression {
     /// (name, index)
     ArrayAccess(String, Box<Expression>),
     BinOp(Box<Expression>, BinOp, Box<Expression>),
+    StructInitialization(String, HashMap<String, Box<Expression>>),
 }
 
 impl TryFrom<Token> for Expression {
diff --git a/src/parser/rules.rs b/src/parser/rules.rs
index 69bf295..6806b6e 100644
--- a/src/parser/rules.rs
+++ b/src/parser/rules.rs
@@ -18,6 +18,7 @@ use super::node_type::*;
 use super::parser::Parser;
 use crate::lexer::Keyword;
 use crate::lexer::{TokenKind, Value};
+use std::collections::HashMap;
 use std::convert::TryFrom;
 
 impl Parser {
@@ -305,10 +306,51 @@ impl Parser {
                 Ok(state)
             }
             TokenKind::SquareBraceOpen => self.parse_array(),
+            TokenKind::Keyword(Keyword::Struct) => self.parse_struct_initialization(),
             other => Err(format!("Expected Expression, found {:?}", other)),
         }
     }
 
+    /// TODO: Cleanup
+    fn parse_struct_initialization(&mut self) -> Result<Expression, String> {
+        let name = self.match_identifier()?;
+        self.match_token(TokenKind::CurlyBracesOpen)?;
+        let fields = self.parse_struct_fields()?;
+        self.match_token(TokenKind::CurlyBracesClose)?;
+
+        Ok(Expression::StructInitialization(name, fields))
+    }
+
+    fn parse_struct_fields(&mut self) -> Result<HashMap<String, Box<Expression>>, String> {
+        let mut map = HashMap::new();
+
+        // If there is a field
+        if let TokenKind::Identifier(_) = self.peek()?.kind {
+            // Parse first field
+            let (name, expr) = self.parse_struct_field()?;
+            map.insert(name, expr);
+            // Then continue to parse fields
+            // as long as a comma token is found
+            while self.peek_token(TokenKind::Comma).is_ok() {
+                self.match_token(TokenKind::Comma)?;
+                let (name, expr) = self.parse_struct_field()?;
+                map.insert(name, expr);
+            }
+        }
+
+        Ok(map)
+    }
+
+    fn parse_struct_field(&mut self) -> Result<(String, Box<Expression>), String> {
+        let next = self.next()?;
+        if let TokenKind::Identifier(name) = next.kind {
+            self.match_token(TokenKind::Colon)?;
+            return Ok((name, Box::new(self.parse_expression()?)));
+        }
+
+        Err(format!("Struct field could not be parsed: {}", next.raw))
+    }
+
     fn parse_array(&mut self) -> Result<Expression, String> {
         let mut elements = Vec::new();
         loop {