From 927faf30c623e81537b6a5e9874b02ee8162283a Mon Sep 17 00:00:00 2001
From: Connor Skees <connor1skees@gmail.com>
Date: Thu, 2 Jul 2020 16:32:43 -0400
Subject: [PATCH] eagerly evaluate call args

---
 src/args.rs       | 11 +++++-----
 src/parse/args.rs | 56 +++++++++++++++++++----------------------------
 2 files changed, 29 insertions(+), 38 deletions(-)

diff --git a/src/args.rs b/src/args.rs
index 0314f1f..2ebb8cb 100644
--- a/src/args.rs
+++ b/src/args.rs
@@ -6,6 +6,7 @@ use crate::{
     common::Identifier,
     error::SassResult,
     parse::Parser,
+    value::Value,
     {Cow, Token},
 };
 
@@ -35,7 +36,7 @@ impl FuncArgs {
 }
 
 #[derive(Debug, Clone)]
-pub(crate) struct CallArgs(pub HashMap<CallArg, Vec<Token>>, pub Span);
+pub(crate) struct CallArgs(pub HashMap<CallArg, Spanned<Value>>, pub Span);
 
 #[derive(Debug, Clone, Hash, Eq, PartialEq)]
 pub(crate) enum CallArg {
@@ -100,25 +101,25 @@ impl CallArgs {
     /// Get argument by name
     ///
     /// Removes the argument
-    pub fn get_named<T: Into<Identifier>>(&mut self, val: T) -> Option<Vec<Token>> {
+    pub fn get_named<T: Into<Identifier>>(&mut self, val: T) -> Option<Spanned<Value>> {
         self.0.remove(&CallArg::Named(val.into()))
     }
 
     /// Get a positional argument by 0-indexed position
     ///
     /// Removes the argument
-    pub fn get_positional(&mut self, val: usize) -> Option<Vec<Token>> {
+    pub fn get_positional(&mut self, val: usize) -> Option<Spanned<Value>> {
         self.0.remove(&CallArg::Positional(val))
     }
 
-    pub fn get<T: Into<Identifier>>(&mut self, position: usize, name: T) -> Option<Vec<Token>> {
+    pub fn get<T: Into<Identifier>>(&mut self, position: usize, name: T) -> Option<Spanned<Value>> {
         match self.get_named(name) {
             Some(v) => Some(v),
             None => self.get_positional(position),
         }
     }
 
-    pub fn get_err(&mut self, position: usize, name: &'static str) -> SassResult<Vec<Token>> {
+    pub fn get_err(&mut self, position: usize, name: &'static str) -> SassResult<Spanned<Value>> {
         match self.get_named(name) {
             Some(v) => Ok(v),
             None => match self.get_positional(position) {
diff --git a/src/parse/args.rs b/src/parse/args.rs
index 1736934..9bd48d8 100644
--- a/src/parse/args.rs
+++ b/src/parse/args.rs
@@ -125,7 +125,7 @@ impl<'a> Parser<'a> {
     }
 
     pub(super) fn parse_call_args(&mut self) -> SassResult<CallArgs> {
-        let mut args: HashMap<CallArg, Vec<Token>> = HashMap::new();
+        let mut args = HashMap::new();
         self.whitespace_or_comment();
         let mut name = String::new();
         let mut val: Vec<Token> = Vec::new();
@@ -176,7 +176,10 @@ impl<'a> Parser<'a> {
                             } else {
                                 CallArg::Named(name.into())
                             },
-                            val,
+                            {
+                                let val = self.parse_value_from_vec(val)?;
+                                val.node.eval(val.span)?
+                            },
                         );
                         span = span.merge(tok.pos());
                         return Ok(CallArgs(args, span));
@@ -204,7 +207,10 @@ impl<'a> Parser<'a> {
                 } else {
                     CallArg::Named(name.as_str().into())
                 },
-                mem::take(&mut val),
+                {
+                    let val = self.parse_value_from_vec(mem::take(&mut val))?;
+                    val.node.eval(val.span)?
+                },
             );
             self.whitespace();
 
@@ -222,11 +228,7 @@ impl<'a> Parser<'a> {
         position: usize,
         name: &'static str,
     ) -> SassResult<Value> {
-        Ok(self
-            .parse_value_from_vec(args.get_err(position, name)?)?
-            .node
-            .eval(args.span())?
-            .node)
+        Ok(args.get_err(position, name)?.node)
     }
 
     pub fn default_arg(
@@ -237,12 +239,7 @@ impl<'a> Parser<'a> {
         default: Value,
     ) -> SassResult<Value> {
         Ok(match args.get(position, name) {
-            Some(toks) => {
-                self.parse_value_from_vec(toks)?
-                    .node
-                    .eval(args.span())?
-                    .node
-            }
+            Some(val) => val.node,
             None => default,
         })
     }
@@ -251,17 +248,13 @@ impl<'a> Parser<'a> {
         &mut self,
         args: &mut CallArgs,
         position: usize,
-    ) -> Option<SassResult<Spanned<Value>>> {
-        Some(self.parse_value_from_vec(args.get_positional(position)?))
+    ) -> Option<Spanned<Value>> {
+        args.get_positional(position)
     }
 
     #[allow(dead_code)]
-    fn named_arg(
-        &mut self,
-        args: &mut CallArgs,
-        name: &'static str,
-    ) -> Option<SassResult<Spanned<Value>>> {
-        Some(self.parse_value_from_vec(args.get_named(name)?))
+    fn named_arg(&mut self, args: &mut CallArgs, name: &'static str) -> Option<Spanned<Value>> {
+        args.get_named(name)
     }
 
     pub fn default_named_arg(
@@ -271,31 +264,25 @@ impl<'a> Parser<'a> {
         default: Value,
     ) -> SassResult<Value> {
         Ok(match args.get_named(name) {
-            Some(toks) => {
-                self.parse_value_from_vec(toks)?
-                    .node
-                    .eval(args.span())?
-                    .node
-            }
+            Some(val) => val.node,
             None => default,
         })
     }
 
     pub fn variadic_args(&mut self, args: CallArgs) -> SassResult<Vec<Spanned<Value>>> {
         let mut vals = Vec::new();
-        let span = args.span();
         let mut args = match args
             .0
             .into_iter()
             .map(|(a, v)| Ok((a.position()?, v)))
-            .collect::<Result<Vec<(usize, Vec<Token>)>, String>>()
+            .collect::<Result<Vec<(usize, Spanned<Value>)>, String>>()
         {
             Ok(v) => v,
             Err(e) => return Err((format!("No argument named ${}.", e), args.1).into()),
         };
         args.sort_by(|(a1, _), (a2, _)| a1.cmp(a2));
         for arg in args {
-            vals.push(self.parse_value_from_vec(arg.1)?.node.eval(span)?);
+            vals.push(arg.1);
         }
         Ok(vals)
     }
@@ -322,9 +309,12 @@ impl<'a> Parser<'a> {
                 break;
             }
             let val = match args.get(idx, arg.name.clone()) {
-                Some(v) => self.parse_value_from_vec(v)?,
+                Some(v) => v,
                 None => match arg.default.as_mut() {
-                    Some(v) => self.parse_value_from_vec(mem::take(v))?,
+                    Some(v) => {
+                        let val = self.parse_value_from_vec(mem::take(v))?;
+                        val.node.eval(val.span)?
+                    }
                     None => {
                         return Err(
                             (format!("Missing argument ${}.", &arg.name), args.span()).into()