Added puts function and formatted project

src/evaluate/builtin.rs

@@ -1,73 +1,94 @@
-use crate::parser::ast::*;
 use crate::evaluate::object::*;
+use crate::parser::ast::*;
 
 pub type BuiltinFunction = fn(Vec<Object>) -> Result<Object, String>;
 
-pub fn get_builtin_functions() -> Vec<(Identifier, Object)>{
-	vec![
-		create_builtin("len", 1, builtin_len),
-		create_builtin("first", 1, builtin_first),
-		create_builtin("last", 1, builtin_last),
-		create_builtin("rest", 1, builtin_rest),
-	]
+pub fn get_builtin_functions() -> Vec<(Identifier, Object)> {
+    vec![
+        create_builtin("len", 1, builtin_len),
+        create_builtin("first", 1, builtin_first),
+        create_builtin("last", 1, builtin_last),
+        create_builtin("rest", 1, builtin_rest),
+        create_builtin("puts", -1, builtin_puts),
+    ]
+}
+
+fn create_builtin(name: &str, param_count: i32, function: BuiltinFunction) -> (Identifier, Object) {
+    (
+        name.to_string(),
+        Object::Builtin(name.to_string(), param_count, function),
+    )
 }
 
-fn create_builtin(name: &str, param_count: usize, function: BuiltinFunction) ->(Identifier, Object){
-	(
-		name.to_string(),
-		Object::Builtin(name.to_string(), param_count, function)
-	)
+fn builtin_len(input: Vec<Object>) -> Result<Object, String> {
+    let input_object = &input[0];
+    match input_object {
+        Object::Array(elem) => Ok(Object::Integer(elem.len() as i32)),
+        Object::String(s) => Ok(Object::Integer(s.len() as i32)),
+        _ => Err(format!(
+            "argument to 'len' not supported, got {}",
+            input_object.type_string()
+        )),
+    }
 }
 
-fn builtin_len(input: Vec<Object>) -> Result<Object, String>{
-	let input_object = &input[0];
-	match input_object {
-		Object::Array(elem) => Ok(Object::Integer(elem.len() as i32)), 
-		Object::String(s) => Ok(Object::Integer(s.len() as i32)),
-		_ => Err(format!("argument to 'len' not supported, got {}", input_object.type_string())),
-	}
+fn builtin_first(input: Vec<Object>) -> Result<Object, String> {
+    let input_object = &input[0];
+    match input_object {
+        Object::Array(elem) => {
+            if elem.len() > 0 {
+                Ok(elem[0].clone())
+            } else {
+                Ok(Object::Null)
+            }
+        }
+        _ => Err(format!(
+            "argument to 'first' not supported, got {}",
+            input_object.type_string()
+        )),
+    }
 }
 
-fn builtin_first(input: Vec<Object>) -> Result<Object, String>{
-	let input_object = &input[0];
-	match input_object {
-		Object::Array(elem) => {
-			if elem.len() > 0{
-				Ok(elem[0].clone())
-			}else{
-				Ok(Object::Null)
-			}			
-		}, 
-		_ => Err(format!("argument to 'first' not supported, got {}", input_object.type_string())),
-	}
+fn builtin_last(input: Vec<Object>) -> Result<Object, String> {
+    let input_object = &input[0];
+    match input_object {
+        Object::Array(elem) => {
+            if elem.len() > 0 {
+                Ok(elem[elem.len() - 1].clone())
+            } else {
+                Ok(Object::Null)
+            }
+        }
+        _ => Err(format!(
+            "argument to 'last' not supported, got {}",
+            input_object.type_string()
+        )),
+    }
 }
 
-fn builtin_last(input: Vec<Object>) -> Result<Object, String>{
-	let input_object = &input[0];
-	match input_object {
-		Object::Array(elem) => {
-			if elem.len() > 0{
-				Ok(elem[elem.len()-1].clone())
-			}else{
-				Ok(Object::Null)
-			}			
-		},
-		_ => Err(format!("argument to 'last' not supported, got {}", input_object.type_string())),
-	}
+fn builtin_rest(input: Vec<Object>) -> Result<Object, String> {
+    let input_object = &input[0];
+    match input_object {
+        Object::Array(elem) => {
+            if elem.len() > 0 {
+                let mut new_elem = elem.clone();
+                new_elem.remove(0);
+                Ok(Object::Array(new_elem))
+            } else {
+                Ok(Object::Null)
+            }
+        }
+        _ => Err(format!(
+            "argument to 'rest' not supported, got {}",
+            input_object.type_string()
+        )),
+    }
 }
 
-fn builtin_rest(input: Vec<Object>) -> Result<Object, String>{
-	let input_object = &input[0];
-	match input_object {
-		Object::Array(elem) => {
-			if elem.len() > 0{
-				let mut new_elem = elem.clone();
-				new_elem.remove(0);
-				Ok(Object::Array(new_elem))
-			}else{
-				Ok(Object::Null)
-			}			
-		},
-		_ => Err(format!("argument to 'rest' not supported, got {}", input_object.type_string())),
-	}
-}
+fn builtin_puts(input: Vec<Object>) -> Result<Object, String> {
+    for object in input.iter() {
+        println!("{}", object.inspect());
+    }
+
+    Ok(Object::Null)
+}