From 3b896fa6c4562467c3dce4ca397cd9c8aaaac5ed Mon Sep 17 00:00:00 2001
From: teo3300 <matteo.rogora@live.it>
Date: Mon, 17 Jun 2024 02:16:51 +0900
Subject: [PATCH] Adding map for HOF

---
 Makefile             |  4 +++-
 src/core.rs          |  4 +++-
 src/env.rs           | 32 ++++++++++++++++++++++++++++++++
 src/mal_tests/mod.rs |  5 +++++
 tests/map.mal        |  5 +++++
 5 files changed, 48 insertions(+), 2 deletions(-)
 create mode 100644 tests/map.mal

diff --git a/Makefile b/Makefile
index 732661a..fab3894 100644
--- a/Makefile
+++ b/Makefile
@@ -6,8 +6,10 @@ build-release:
 test:
 	cargo test --release
 
-install: build-release
+conf:
 	mkdir -p ${HOME}/.config/mal
 	cp -f core/core.mal ${HOME}/.config/mal/
+
+install: build-release conf
 	sudo cp target/release/rust-mal /usr/local/bin/mal
 	sudo chown ${USER} /usr/local/bin/mal
diff --git a/src/core.rs b/src/core.rs
index fa8a286..770c383 100644
--- a/src/core.rs
+++ b/src/core.rs
@@ -1,7 +1,8 @@
 use std::{cell::RefCell, env, rc::Rc};
 
 use crate::env::{
-    any_zero, arithmetic_op, car, comparison_op, env_new, env_set, mal_car, mal_cdr, mal_exit, Env,
+    any_zero, arithmetic_op, car, comparison_op, env_new, env_set, mal_car, mal_cdr, mal_exit,
+    mal_map, Env,
 };
 
 // This is the first time I implement a macro, and I'm copying it
@@ -80,6 +81,7 @@ pub fn ns_init() -> Env {
         "atom"          => Fun(|a| Ok(Atom(Rc::new(RefCell::new(car(a).unwrap_or_default().clone())))), "Return an atom pointing to the given arg"),
         "deref"         => Fun(|a| if_atom!(car(a)?), "Return the content of the atom argumet"),
         "reset!"        => Fun(reset_bang, "Change the value of the Atom (frist argument) to the second argument"),
+        "map"           => Fun(mal_map, "Apply the first argument to all the elements of the second arguments"),
         "env"           => Fun(|a| match env::var(car(a)?.if_string()?) {
             Ok(s) => Ok(Str(s.into())),
             _ => Ok(Nil),
diff --git a/src/env.rs b/src/env.rs
index 04d5839..5ae74a3 100644
--- a/src/env.rs
+++ b/src/env.rs
@@ -189,6 +189,38 @@ pub fn car_cdr(list: &[MalType]) -> Result<(&MalType, &[MalType]), MalErr> {
     Ok((car(list)?, cdr(list)))
 }
 
+pub fn mal_map(args: &[MalType]) -> MalRet {
+    let mut ret = Vec::new();
+    let (lambda, list) = car_cdr(args)?;
+    let list = car(list)?.if_list()?;
+    match lambda {
+        M::Fun(func, _) => {
+            for el in list {
+                ret.push(func(&[el.clone()])?);
+            }
+        }
+        M::MalFun {
+            params, ast, env, ..
+        } => {
+            for el in list {
+                let inner_env = env_binds(env.clone(), params, &[el.clone()])?;
+                match ast.as_ref() {
+                    M::List(ops) => {
+                        let mut last = MalType::Nil;
+                        for x in &ops[0..ops.len()] {
+                            last = eval(x, inner_env.clone())?;
+                        }
+                        ret.push(last)
+                    }
+                    _ => scream!(),
+                }
+            }
+        }
+        _ => scream!(),
+    };
+    Ok(MalType::List(ret.into()))
+}
+
 fn first(list: &[MalType]) -> &[MalType] {
     if list.len() > 1 {
         &list[..list.len() - 1]
diff --git a/src/mal_tests/mod.rs b/src/mal_tests/mod.rs
index cc6c746..c1db999 100644
--- a/src/mal_tests/mod.rs
+++ b/src/mal_tests/mod.rs
@@ -60,4 +60,9 @@ mod functional {
     fn car_cdr() {
         test!("car-cdr")
     }
+
+    #[test]
+    fn map() {
+        test!("map")
+    }
 }
diff --git a/tests/map.mal b/tests/map.mal
new file mode 100644
index 0000000..8d035fc
--- /dev/null
+++ b/tests/map.mal
@@ -0,0 +1,5 @@
+; builtin map
+(assert-eq '((1) (2) (3)) (map list '(1 2 3)))
+
+; lambda map
+(assert-eq '(2 3 4) (map (fn* [x] (+ x 1)) '(1 2 3)))