list contains implemented

Readme.org

@@ -478,7 +478,6 @@ Note: this section only tracks the state of incomplete TODO items. Having everyt
 
 ** TODO Pre-alpha tasks
 - Shell prompt is fully configurable (History, L, R, and Delim)
-- userlib list contains
 - Input function
 - Lex function
 - Read function (Input + Lex)

snippets/userlib-tests.rls

@@ -55,6 +55,18 @@
              (adder (lambda (x y) (add x y))))
          (eq? (reduce adder list) (add 1 2 3)))))
 
+   ('contains? finds elem in list'
+     (quote
+       (contains? (1 2 3) 1)))
+
+   ('contains? finds last elem in list'
+     (quote
+       (contains? (1 2 3) 3)))
+
+   ('contains? doesnt find elem not in list'
+     (quote
+       (not (contains? (1 2 3) 4))))
+
      ;; add more test cases here
    ))
 

snippets/userlib.rls

@@ -85,3 +85,18 @@ this will continue iuntil the list is exhausted.'
           (set (q result) (func result current))
           (set (q list-iter) (pop remaining)))))
   result))
+
+(def contains?
+'Takes two arguments: a list and an element.
+Returns true if the list contains the element.'
+(list elem)
+(let ((found false)
+      (list-iter (pop list)))
+  (while (and (gt? (len list-iter) 1)
+              (not found))
+    (let ((current (car list-iter))
+          (remaining (cdr list-iter)))
+      (if (eq? current elem)
+        (set (q found) true)
+        (set (q list-iter) (pop remaining)))))
+  found))

src/run.rs

@@ -120,6 +120,7 @@ pub fn run_callback(ast: &Seg, syms: &mut SymTable) ->  Result<Ctr, String> {
     if let Ok(s) = current_dir() {
         prefixes.push(String::from(s.to_str().unwrap()));
     }
+    prefixes.push(String::from("/"));
     if let Ctr::String(ref filename) = *ast.car {
         for prefix in prefixes {
             let candidate = Path::new(&prefix.clone()).join(filename);

src/stl.rs

@@ -68,13 +68,13 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
     );
 
     syms.insert(
-        "contains".to_string(),
+        "substr?".to_string(),
         Symbol {
-            name: String::from("contains"),
+            name: String::from("substr?"),
             args: Args::Strict(vec![Type::String, Type::String]),
             conditional_branches: false,
-            docs: strings::CONTAINS_DOCSTRING.to_string(),
-            value: ValueType::Internal(Rc::new(strings::contains_callback)),
+            docs: strings::SUBSTR_DOCSTRING.to_string(),
+            value: ValueType::Internal(Rc::new(strings::substr_callback)),
             ..Default::default()
         },
     );

src/stl/strings.rs

@@ -90,10 +90,10 @@ pub fn strcast_callback(ast: &Seg, _syms: &mut SymTable) -> Result<Ctr, String>
     }
 }
 
-pub const CONTAINS_DOCSTRING: &str =
+pub const SUBSTR_DOCSTRING: &str =
     "Takes two strings. Returns true if string1 contains at least one instance of string2";
 
-pub fn contains_callback(ast: &Seg, _syms: &mut SymTable) -> Result<Ctr, String> {
+pub fn substr_callback(ast: &Seg, _syms: &mut SymTable) -> Result<Ctr, String> {
     let parent_str: String;
     if let Ctr::String(ref s) = *ast.car {
         parent_str = s.to_string();

tests/test_lib_str.rs

@@ -154,7 +154,7 @@ mod str_lib_tests {
 
     #[test]
     fn test_contains() {
-        let document = "(contains 'bigger' 'ger')";
+        let document = "(substr? 'bigger' 'ger')";
         let result = "true";
         let mut syms = SymTable::new();
         static_stdlib(&mut syms).unwrap();
@@ -169,7 +169,7 @@ mod str_lib_tests {
 
     #[test]
     fn test_doesnt_contain() {
-        let document = "(contains 'smaller' 'ger')";
+        let document = "(substr? 'smaller' 'ger')";
         let result = "false";
         let mut syms = SymTable::new();
         static_stdlib(&mut syms).unwrap();