initial implementation of get-function()

src/atrule/function.rs

@@ -4,6 +4,7 @@ use super::eat_stmts;
 
 use crate::args::{eat_func_args, CallArgs, FuncArgs};
 use crate::atrule::AtRule;
+use crate::common::Pos;
 use crate::error::SassResult;
 use crate::scope::Scope;
 use crate::selector::Selector;
@@ -16,11 +17,25 @@ pub(crate) struct Function {
     scope: Scope,
     args: FuncArgs,
     body: Vec<Stmt>,
+    pos: Pos,
 }
 
+impl PartialEq for Function {
+    fn eq(&self, other: &Self) -> bool {
+        self.pos == other.pos
+    }
+}
+
+impl Eq for Function {}
+
 impl Function {
-    pub fn new(scope: Scope, args: FuncArgs, body: Vec<Stmt>) -> Self {
-        Function { scope, args, body }
+    pub fn new(scope: Scope, args: FuncArgs, body: Vec<Stmt>, pos: Pos) -> Self {
+        Function {
+            scope,
+            args,
+            body,
+            pos,
+        }
     }
 
     pub fn decl_from_tokens<I: Iterator<Item = Token>>(
@@ -28,6 +43,7 @@ impl Function {
         scope: Scope,
         super_selector: &Selector,
     ) -> SassResult<(String, Function)> {
+        let pos = toks.peek().unwrap().pos;
         let name = eat_ident(toks, &scope, super_selector)?;
         devour_whitespace(toks);
         let args = match toks.next() {
@@ -40,7 +56,7 @@ impl Function {
         let body = eat_stmts(toks, &mut scope.clone(), super_selector)?;
         devour_whitespace(toks);
 
-        Ok((name, Function::new(scope, args, body)))
+        Ok((name, Function::new(scope, args, body, pos)))
     }
 
     pub fn args(mut self, mut args: CallArgs) -> SassResult<Function> {

src/builtin/meta.rs

@@ -133,6 +133,19 @@ pub(crate) fn register(f: &mut HashMap<String, Builtin>) {
             }
         }),
     );
+    f.insert(
+        "get-function".to_owned(),
+        Box::new(|mut args, scope| {
+            max_args!(args, 2);
+            let name = match arg!(args, 0, "name") {
+                Value::Ident(s, _) => s,
+                v => return Err(format!("$name: {} is not a string.", v).into()),
+            };
+            let css = arg!(args, 1, "css" = Value::False).is_true()?;
+
+            Ok(Value::Function(Box::new(scope.get_fn(&name)?), css))
+        }),
+    );
     f.insert("call".to_owned(), Box::new(|_args, _scope| {
         todo!("builtin function `call()` is blocked on refactoring how call args are stored and parsed")
         // let func = arg!(args, 0, "function").to_string();

src/value/mod.rs

@@ -2,6 +2,7 @@ use std::cmp::Ordering;
 use std::fmt::{self, Display, Write};
 use std::iter::Iterator;
 
+use crate::atrule::Function;
 use crate::color::Color;
 use crate::common::{Brackets, ListSeparator, Op, QuoteKind};
 use crate::error::SassResult;
@@ -30,8 +31,8 @@ pub(crate) enum Value {
     Ident(String, QuoteKind),
     Map(SassMap),
     ArgList(Vec<Value>),
-    // Returned by `get-function()`
-    // Function(String)
+    /// Returned by `get-function()`
+    Function(Box<Function>, bool),
 }
 
 impl Display for Value {
@@ -53,6 +54,7 @@ impl Display for Value {
                     .collect::<Vec<String>>()
                     .join(", ")
             ),
+            Self::Function(..) => todo!("invalid CSS"),
             Self::List(vals, sep, brackets) => match brackets {
                 Brackets::None => write!(
                     f,
@@ -166,7 +168,7 @@ impl Value {
             Self::Ident(..) | Self::Important => Ok("string"),
             Self::Dimension(..) => Ok("number"),
             Self::List(..) => Ok("list"),
-            // Self::Function(..) => Ok("function"),
+            Self::Function(..) => Ok("function"),
             Self::ArgList(..) => Ok("arglist"),
             Self::True | Self::False => Ok("bool"),
             Self::Null => Ok("null"),

src/value/ops.rs

@@ -14,7 +14,7 @@ impl Add for Value {
         }
         let precedence = Op::Plus.precedence();
         Ok(match self {
-            Self::ArgList(..) | Self::Map(..) => todo!(),
+            Self::Function(..) | Self::ArgList(..) | Self::Map(..) => todo!(),
             Self::Important | Self::True | Self::False => match other {
                 Self::Ident(s, QuoteKind::Double) | Self::Ident(s, QuoteKind::Single) => {
                     Value::Ident(format!("{}{}", self, s), QuoteKind::Double)
@@ -86,7 +86,7 @@ impl Add for Value {
                 Self::List(..) => Value::Ident(format!("{}{}", s1, other), quotes1),
                 Self::UnaryOp(..) | Self::BinaryOp(..) => todo!(),
                 Self::Paren(..) => (Self::Ident(s1, quotes1) + other.eval()?)?,
-                Self::ArgList(..) | Self::Map(..) => todo!(),
+                Self::Function(..) | Self::ArgList(..) | Self::Map(..) => todo!(),
             },
             Self::List(..) => match other {
                 Self::Ident(s, q) => Value::Ident(format!("{}{}", self, s), q.normalize()),

tests/get-function.rs

@@ -0,0 +1,34 @@
+#![cfg(test)]
+
+#[macro_use]
+mod macros;
+
+test!(
+    different_function_same_body_not_equal,
+    "@function user-defined() {@return null}
+    $first-reference: get-function(user-defined);
+    
+    @function user-defined() {@return null}
+    $second-reference: get-function(user-defined);
+    a {b: $first-reference == $second-reference}",
+    "a {\n  b: false;\n}\n"
+);
+test!(
+    same_function_equal,
+    "@function user-defined() {@return null}
+    a {b: get-function(user-defined) == get-function(user-defined)}s",
+    "a {\n  b: true;\n}\n"
+);
+test!(
+    different_name_same_body_not_equal,
+    "@function user-defined-1() {@return null}
+     @function user-defined-2() {@return null}
+     a {b: get-function(user-defined-1) == get-function(user-defined-2)}",
+    "a {\n  b: false;\n}\n"
+);
+test!(
+    type_of_user_defined_function,
+    "@function user-defined() {@return null}
+     a {b: type-of(get-function(user-defined));}",
+    "a {\n  b: function;\n}\n"
+);