Chore: CI fixes and readme updates (#4)

* Update README to include array support and CI pipeline details

* Refactor code for consistency and readability by adding missing commas and formatting adjustments across multiple files

* Update Rust toolchain version to 1.87 in CI configuration

Author: shubhiscoding

.github/workflows/ci.yaml

@@ -14,7 +14,7 @@ jobs:
       - name: Set up Rust
         uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: "1.85"
+          toolchain: "1.87"
           components: rustfmt, clippy
       - name: Build
         run: cargo build --verbose

README.md

@@ -89,56 +89,25 @@ The WASM backend will:
 * 🔢 Increment / decrement (`i++`, `i--`)
 * 🔧 Functions with parameters, return values, and recursion
 * 🧩 Nested function calls (`add(add(1,2), 3)`)
+* 📦 Arrays (literals, index read/write, pass to functions)
 * 🖨️ Print statements (`print x;`)
 * 🔁 REPL (interactive shell)
 * 📂 File execution (`rusty run file.rts`)
+* ✅ CI pipeline (GitHub Actions)
 
 ---
 
-## 🧪 Example
-
-```ts
-let x = (2 + 3) * 4;
-print "x = " + x;
-
-function max(a, b) {
-    if (a > b) {
-        return a;
-    } else {
-        return b;
-    }
-}
-
-print "max is " + max(x, 15);
-
-function factorial(n) {
-    if (n < 2) { return 1; }
-    return n * factorial(n - 1);
-}
-print "5! = " + factorial(5);
-
-for (let i = 0; i < 5; i++) {
-    if (i == 2) { continue; }
-    if (i == 4) { break; }
-    print i;
-}
-
-let name = "Rusty";
-if (name && x > 10) {
-    print name + " works!";
-}
-```
+## 🧪 Examples
 
-Output:
+Check out the [`example/`](example/) folder for sample RTS programs, including:
 
-```
-x = 20
-max is 20
-5! = 120
-0
-1
-3
-Rusty works!
+- [`test.rts`](example/test.rts) — array basics (literals, indexing, mutation)
+- [`merge_sort.rts`](example/merge_sort.rts) — merge sort implementation using arrays, functions, and recursion
+
+Run any example with:
+
+```bash
+cargo run -- run example/merge_sort.rts
 ```
 
 ---
@@ -210,15 +179,19 @@ cargo run -- repl
 * [x] Functions (declaration, params, return)
 * [x] Nested / recursive function calls
 * [x] Frame-based call stack
+* [x] Arrays (literals, indexing, mutation)
+* [x] Array pass/return from functions
 * [ ] Type annotations
-* [ ] Arrays and objects
+* [ ] Objects / maps
 * [ ] Closures
+* [ ] `<=`, `>=` operators
 
 ---
 
-### Runtime Evolution
+### Runtime & Tooling
 
 * [x] Bytecode VM
+* [x] CI pipeline (build, test, clippy, fmt)
 * [ ] WASM backend (in progress)
 * [ ] Bytecode optimizations
 * [ ] Register-based VM (optional)

src/ast/mod.rs

@@ -15,13 +15,13 @@ pub enum Statement {
     },
     While {
         condition: Expression,
-        body: Vec<Statement>
+        body: Vec<Statement>,
     },
     For {
         init: Box<Statement>,
         condition: Expression,
         update: Box<Statement>,
-        body: Vec<Statement>
+        body: Vec<Statement>,
     },
     Assignment {
         name: String,
@@ -32,16 +32,16 @@ pub enum Statement {
     Function {
         name: String,
         params: Vec<String>,
-        body: Vec<Statement>
+        body: Vec<Statement>,
     },
     Return {
-        value: Expression
+        value: Expression,
     },
     AssignmentIndex {
         array: String,
         index: Expression,
         value: Expression,
-    }
+    },
 }
 
 #[derive(Debug, Clone, PartialEq)]
@@ -55,7 +55,7 @@ pub enum BinaryOperation {
     Equal,
     NotEqual,
     And,
-    Or
+    Or,
 }
 
 #[derive(Debug, Clone)]
@@ -70,22 +70,22 @@ pub enum Expression {
     },
     Unary {
         op: BinaryOperation,
-        expr: Box<Expression>
+        expr: Box<Expression>,
     },
     Call {
         name: String,
-        args: Vec<Expression>
+        args: Vec<Expression>,
     },
     ArrayLiteral(Vec<Expression>),
     Index {
         array: Box<Expression>,
         index: Box<Expression>,
-    }
+    },
 }
 
 #[derive(Debug, Clone, PartialEq, PartialOrd)]
 pub enum Value {
     Number(i32),
     String(String),
     Array(Vec<Value>),
-}
+}

src/compiler/mod.rs

@@ -5,7 +5,7 @@ use crate::ast::{BinaryOperation, Expression, Statement, Value};
 #[derive(Debug)]
 pub struct FunctionBytecode {
     pub params: Vec<String>,
-    pub instructions: Vec<Instruction>
+    pub instructions: Vec<Instruction>,
 }
 
 pub struct LoopContext {
@@ -17,7 +17,7 @@ pub struct LoopContext {
 #[derive(Debug)]
 pub struct Program {
     pub main: Vec<Instruction>,
-    pub functions: HashMap<String, FunctionBytecode>
+    pub functions: HashMap<String, FunctionBytecode>,
 }
 
 #[derive(Debug, Clone)]
@@ -45,13 +45,15 @@ pub enum Instruction {
     CallFunction(String, usize),
     CreateArray(usize),
     LoadIndex,
-    StoreIndex
+    StoreIndex,
 }
 
 fn compile_expr(instructions: &mut Vec<Instruction>, expr: &Expression) {
     match expr {
         Expression::Number(x) => instructions.push(Instruction::LoadConst(Value::Number(*x))),
-        Expression::String(s) => instructions.push(Instruction::LoadConst(Value::String(s.clone()))),
+        Expression::String(s) => {
+            instructions.push(Instruction::LoadConst(Value::String(s.clone())))
+        }
         Expression::Identifier(val) => instructions.push(Instruction::LoadVar(val.to_string())),
         Expression::Binary { left, op, right } => {
             if *op != BinaryOperation::And && *op != BinaryOperation::Or {
@@ -75,37 +77,38 @@ fn compile_expr(instructions: &mut Vec<Instruction>, expr: &Expression) {
                     let jump_instructions_index = instructions.len() - 1;
                     instructions.push(Instruction::PopTop);
                     compile_expr(instructions, right);
-                    instructions[jump_instructions_index] = Instruction::JumpIfFalse(instructions.len());
+                    instructions[jump_instructions_index] =
+                        Instruction::JumpIfFalse(instructions.len());
                 }
                 BinaryOperation::Or => {
                     instructions.push(Instruction::DuplicateTop);
                     instructions.push(Instruction::JumpIfTrue(0));
                     let jump_instructions_index = instructions.len() - 1;
                     instructions.push(Instruction::PopTop);
                     compile_expr(instructions, right);
-                    instructions[jump_instructions_index] = Instruction::JumpIfTrue(instructions.len());
+                    instructions[jump_instructions_index] =
+                        Instruction::JumpIfTrue(instructions.len());
                 }
             }
         }
         Expression::Unary { op, expr } => {
             compile_expr(instructions, expr);
-            match op {
-                BinaryOperation::Subtraction => instructions.push(Instruction::Negate),
-                _ => {}
+            if op == &BinaryOperation::Subtraction {
+                instructions.push(Instruction::Negate);
             }
-        },
+        }
         Expression::Call { name, args } => {
             for arg in args {
                 compile_expr(instructions, arg);
             }
             instructions.push(Instruction::CallFunction(name.clone(), args.len()));
-        },
+        }
         Expression::ArrayLiteral(elements) => {
             for element in elements {
                 compile_expr(instructions, element);
             }
             instructions.push(Instruction::CreateArray(elements.len()));
-        },
+        }
         Expression::Index { array, index } => {
             compile_expr(instructions, array);
             compile_expr(instructions, index);
@@ -124,12 +127,16 @@ pub fn compile_statements(
             Statement::VarDecl { name, value } => {
                 compile_expr(instructions, &value);
                 instructions.push(Instruction::DeclareVar(name));
-            },
+            }
             Statement::Print { value } => {
                 compile_expr(instructions, &value);
                 instructions.push(Instruction::Print);
             }
-            Statement::If { condition, body, else_body } => {
+            Statement::If {
+                condition,
+                body,
+                else_body,
+            } => {
                 compile_expr(instructions, &condition);
 
                 let jump_if_false_index = instructions.len();
@@ -140,11 +147,13 @@ pub fn compile_statements(
                 if let Some(else_body) = else_body {
                     let jump_to_end_index = instructions.len();
                     instructions.push(Instruction::Jump(0));
-                    instructions[jump_if_false_index] = Instruction::JumpIfFalse(instructions.len());
+                    instructions[jump_if_false_index] =
+                        Instruction::JumpIfFalse(instructions.len());
                     compile_statements(else_body, instructions, loop_ctx.as_deref_mut());
                     instructions[jump_to_end_index] = Instruction::Jump(instructions.len());
                 } else {
-                    instructions[jump_if_false_index] = Instruction::JumpIfFalse(instructions.len());
+                    instructions[jump_if_false_index] =
+                        Instruction::JumpIfFalse(instructions.len());
                 }
             }
             Statement::While { condition, body } => {
@@ -171,8 +180,13 @@ pub fn compile_statements(
                 for idx in ctx.break_placeholders {
                     instructions[idx] = Instruction::Jump(instructions.len());
                 }
-            },
-            Statement::For { init, condition, update, body } => {
+            }
+            Statement::For {
+                init,
+                condition,
+                update,
+                body,
+            } => {
                 compile_statements(vec![*init], instructions, loop_ctx.as_deref_mut());
 
                 let loop_start_index = instructions.len();
@@ -201,44 +215,50 @@ pub fn compile_statements(
                 for idx in ctx.break_placeholders {
                     instructions[idx] = Instruction::Jump(instructions.len());
                 }
-            },
+            }
             Statement::Assignment { name, value } => {
                 compile_expr(instructions, &value);
                 instructions.push(Instruction::AssignVar(name));
-            },
+            }
             Statement::Break => {
                 if let Some(ctx) = loop_ctx.as_deref_mut() {
                     instructions.push(Instruction::Jump(0));
                     ctx.break_placeholders.push(instructions.len() - 1);
                 } else {
                     panic!("'break' used outside of a loop");
                 }
-            },
+            }
             Statement::Continue => {
                 if let Some(ctx) = loop_ctx.as_deref_mut() {
                     instructions.push(Instruction::Jump(0));
                     ctx.continue_placeholders.push(instructions.len() - 1);
                 } else {
                     panic!("'continue' used outside of a loop");
                 }
-            },
-            Statement::Function { name:_, params:_, body:_ }  => {},
+            }
+            Statement::Function {
+                name: _,
+                params: _,
+                body: _,
+            } => {}
             Statement::Return { value } => {
                 compile_expr(instructions, &value);
                 instructions.push(Instruction::Return);
-            },
-            Statement::Expression(expr) => {
-                match expr {
-                    Expression::Call { name, args } => {
-                        for arg in &args {
-                            compile_expr(instructions, arg);
-                        }
-                        instructions.push(Instruction::CallFunction(name.clone(), args.len()));
-                    },
-                    _ => compile_expr(instructions, &expr)
+            }
+            Statement::Expression(expr) => match expr {
+                Expression::Call { name, args } => {
+                    for arg in &args {
+                        compile_expr(instructions, arg);
+                    }
+                    instructions.push(Instruction::CallFunction(name.clone(), args.len()));
                 }
+                _ => compile_expr(instructions, &expr),
             },
-            Statement::AssignmentIndex { array, index, value } => {
+            Statement::AssignmentIndex {
+                array,
+                index,
+                value,
+            } => {
                 instructions.push(Instruction::LoadVar(array.clone()));
 
                 // index is expression
@@ -262,11 +282,20 @@ pub fn compile_program(statements: Vec<Statement>) -> Program {
         if let Statement::Function { name, params, body } = statement {
             let mut func_instructions = Vec::new();
             compile_statements(body, &mut func_instructions, None);
-            functions.insert(name, FunctionBytecode { params, instructions: func_instructions });
+            functions.insert(
+                name,
+                FunctionBytecode {
+                    params,
+                    instructions: func_instructions,
+                },
+            );
         } else {
             compile_statements(vec![statement], &mut main_instructions, None);
         }
     }
 
-    Program { main: main_instructions, functions }
-}
+    Program {
+        main: main_instructions,
+        functions,
+    }
+}