Implemented SymTable optimization for efficient variable updates

src/config.rs

@@ -40,6 +40,7 @@ pub fn configure(filename: String, syms: &mut SymTable) -> Result<(), String> {
 
     default value: false".to_string(),
             value: ValueType::VarForm(Box::new(Ctr::Bool(false))),
+            ..Default::default()
         },
     );
 
@@ -56,6 +57,7 @@ checked at shell startup by configuration daemon. not used afterwards.
 default value: 1 (set)
 ".to_string(),
             value: ValueType::VarForm(Box::new(Ctr::Bool(true))),
+            ..Default::default()
         },
     );
 
@@ -69,6 +71,7 @@ default value: 1 (set)
 default value (<lambda>)"
                 .to_string(),
             value: ValueType::Internal(Rc::new(prompt_default_callback)),
+            ..Default::default()
         },
     );
 

src/stl.rs

@@ -38,6 +38,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: append::CONS_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(append::cons_callback)),
+            ..Default::default()
         },
     );
 
@@ -49,6 +50,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: strings::ECHO_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(strings::echo_callback)),
+            ..Default::default()
         },
     );
 
@@ -60,6 +62,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: strings::CONCAT_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(strings::concat_callback)),
+            ..Default::default()
         },
     );
 
@@ -71,6 +74,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: strings::CONTAINS_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(strings::contains_callback)),
+            ..Default::default()
         },
     );
 
@@ -82,6 +86,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: strings::SPLIT_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(strings::split_callback)),
+            ..Default::default()
         },
     );
 
@@ -93,6 +98,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: strings::STRLEN_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(strings::strlen_callback)),
+            ..Default::default()
         },
     );
 
@@ -104,6 +110,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: strings::STRCAST_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(strings::strcast_callback)),
+            ..Default::default()
         },
     );
 
@@ -115,6 +122,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: true,
             docs: control::IF_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(control::if_callback)),
+            ..Default::default()
         },
     );
 
@@ -126,6 +134,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: true,
             docs: control::LET_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(control::let_callback)),
+            ..Default::default()
         },
     );
 
@@ -137,6 +146,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: true,
             docs: control::WHILE_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(control::while_callback)),
+            ..Default::default()
         },
     );
 
@@ -148,6 +158,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: true,
             docs: control::CIRCUIT_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(control::circuit_callback)),
+            ..Default::default()
         },
     );
 
@@ -159,6 +170,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: boolean::AND_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(boolean::and_callback)),
+            ..Default::default()
         },
     );
 
@@ -170,6 +182,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: boolean::BOOLCAST_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(boolean::boolcast_callback)),
+            ..Default::default()
         },
     );
 
@@ -181,6 +194,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: boolean::OR_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(boolean::or_callback)),
+            ..Default::default()
         },
     );
 
@@ -192,6 +206,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: boolean::NOT_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(boolean::not_callback)),
+            ..Default::default()
         },
     );
 
@@ -203,6 +218,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: boolean::ISEQ_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(boolean::iseq_callback)),
+            ..Default::default()
         },
     );
 
@@ -214,6 +230,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: true,
             docs: boolean::TOGGLE_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(boolean::toggle_callback)),
+            ..Default::default()
         },
     );
 
@@ -225,6 +242,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: true,
             docs: decl::HELP_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(decl::help_callback)),
+            ..Default::default()
         },
     );
 
@@ -236,6 +254,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: true,
             docs: decl::ISSET_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(decl::isset_callback)),
+            ..Default::default()
         },
     );
 
@@ -247,6 +266,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: decl::ENV_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(decl::env_callback)),
+            ..Default::default()
         },
     );
 
@@ -258,6 +278,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: math::ADD_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(math::add_callback)),
+            ..Default::default()
         },
     );
 
@@ -269,6 +290,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: math::SUB_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(math::sub_callback)),
+            ..Default::default()
         },
     );
 
@@ -280,6 +302,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: math::DIV_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(math::div_callback)),
+            ..Default::default()
         },
     );
 
@@ -291,6 +314,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: math::MUL_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(math::mul_callback)),
+            ..Default::default()
         },
     );
 
@@ -302,6 +326,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: math::INTCAST_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(math::intcast_callback)),
+            ..Default::default()
         },
     );
 
@@ -313,6 +338,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: math::FLOATCAST_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(math::floatcast_callback)),
+            ..Default::default()
         },
     );
 
@@ -324,6 +350,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: append::LEN_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(append::len_callback)),
+            ..Default::default()
         },
     );
 
@@ -335,6 +362,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: append::CAR_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(append::car_callback)),
+            ..Default::default()
         },
     );
 
@@ -346,6 +374,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: append::CDR_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(append::cdr_callback)),
+            ..Default::default()
         },
     );
 
@@ -357,6 +386,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: append::POP_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(append::pop_callback)),
+            ..Default::default()
         },
     );
 
@@ -368,6 +398,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: append::DEQUEUE_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(append::dequeue_callback)),
+            ..Default::default()
         },
     );
 
@@ -379,6 +410,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: append::REVERSE_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(append::reverse_callback)),
+            ..Default::default()
         },
     );
 
@@ -390,6 +422,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: math::EXP_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(math::exp_callback)),
+            ..Default::default()
         },
     );
 
@@ -401,6 +434,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: math::MOD_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(math::mod_callback)),
+            ..Default::default()
         },
     );
 
@@ -412,6 +446,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: math::ISGT_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(math::isgt_callback)),
+            ..Default::default()
         },
     );
 
@@ -423,6 +458,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: math::ISLT_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(math::islt_callback)),
+            ..Default::default()
         },
     );
 
@@ -434,6 +470,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: math::ISGTE_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(math::isgte_callback)),
+            ..Default::default()
         },
     );
 
@@ -445,6 +482,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: math::ISLTE_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(math::islte_callback)),
+            ..Default::default()
         },
     );
 
@@ -456,6 +494,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: true,
             docs: math::INC_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(math::inc_callback)),
+            ..Default::default()
         },
     );
 
@@ -467,6 +506,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: true,
             docs: math::DEC_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(math::dec_callback)),
+            ..Default::default()
         },
     );
 
@@ -478,6 +518,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: true,
             docs: decl::QUOTE_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(decl::quote_callback)),
+            ..Default::default()
         },
     );
 
@@ -489,6 +530,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: true,
             docs: decl::QUOTE_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(decl::quote_callback)),
+            ..Default::default()
         },
     );
 
@@ -500,6 +542,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: true,
             docs: decl::EVAL_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(decl::eval_callback)),
+            ..Default::default()
         },
     );
 
@@ -511,6 +554,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: true,
             docs: decl::LAMBDA_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(decl::lambda_callback)),
+            ..Default::default()
         }
     );
 
@@ -522,6 +566,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: decl::GETDOC_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(decl::getdoc_callback)),
+            ..Default::default()
         }
     );
 
@@ -533,6 +578,7 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
             conditional_branches: false,
             docs: decl::SETDOC_DOCSTRING.to_string(),
             value: ValueType::Internal(Rc::new(decl::setdoc_callback)),
+            ..Default::default()
         }
     );
 
@@ -562,6 +608,7 @@ pub fn dynamic_stdlib(syms: &mut SymTable) -> Result<(), String> {
                     decl::store_callback(ast, syms, env_cfg_user_form)
                 },
             )),
+            ..Default::default()
         },
     );
 

src/stl/control.rs

@@ -202,22 +202,10 @@ pub fn let_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, String> {
         return Err("evaluation failure".to_string());
     }
 
-    // we need to get any var declared from within the let eval forms
-    // those need to exist in the outside context
-    // TODO: make this more optimal
-    //     How can we skip iterations?
-    //     implement a counter for number of calls to def
-    //     store it inside the SymTable and Symbol
-    //     only re-insert into global scope what is most recent
-    for i in localsyms.iter() {
-        if !locals.contains(i.0) {
-            syms.insert(
-                i.0.clone(),
-                i.1.clone(),
-            );
-        }
+    for i in locals {
+        localsyms.remove(&i);
     }
-
+    syms.update(&mut localsyms);
     Ok((*result).clone())
 }
 

src/sym.rs

@@ -22,7 +22,7 @@ use std::fmt;
 use std::rc::Rc;
 
 #[derive(Clone)]
-pub struct SymTable(HashMap<String, Symbol>);
+pub struct SymTable(HashMap<String, Symbol>, usize);
 
 #[derive(Debug, Clone)]
 pub struct UserFn {
@@ -68,11 +68,14 @@ pub struct Symbol {
     // eval() will not eval the args
     pub conditional_branches: bool,
     pub docs: String,
+    // see SymTable::Insert
+    // (only pub begrudgingly
+    pub __generation: usize,
 }
 
 impl SymTable {
     pub fn new() -> SymTable {
-        SymTable(HashMap::<String, Symbol>::new())
+        SymTable(HashMap::<String, Symbol>::new(), 0)
     }
 
     pub fn get(&self, arg: &String) -> Option<&Symbol> {
@@ -83,7 +86,9 @@ impl SymTable {
         self.0.contains_key(arg)
     }
 
-    pub fn insert(&mut self, k: String, v: Symbol) -> Option<Symbol> {
+    pub fn insert(&mut self, k: String, mut v: Symbol) -> Option<Symbol> {
+        self.1 += 1;
+        v.__generation = self.1;
         self.0.insert(k, v)
     }
 
@@ -95,16 +100,40 @@ impl SymTable {
         self.0.iter()
     }
 
+    pub fn update(&mut self, other: &mut SymTable) {
+        /* updates self with all syms in other that match the following cases:
+         *   * sym is not in self
+         *   * sym has a newer generation than the entry in self
+         */
+        for i in other.iter() {
+            self.0.entry(i.0.to_string())
+                .and_modify(|inner: &mut Symbol| {
+                    if inner.__generation < i.1.__generation {
+                        inner.__generation = i.1.__generation;
+                        inner.value = i.1.value.clone();
+                        inner.args = i.1.args.clone();
+                        inner.docs = i.1.docs.clone();
+                        inner.conditional_branches = i.1.conditional_branches;
+                        inner.name = i.1.name.clone();
+                    }
+                })
+                .or_insert(i.1.clone());
+        }
+    }
+
     pub fn call_symbol(
         &mut self,
         name: &String,
         args: &Seg,
         call_func: bool,
     ) -> Result<Box<Ctr>, String> {
-        let symbol = match self.remove(name) {
+        let mut symbol = match self.remove(name) {
             Some(s) => s,
             None => return Err(format!("undefined symbol: {}", name)),
         };
+        // will re-increment when inserted
+        // but we dont want to increment it
+        symbol.__generation -= 1;
         self.insert(name.to_string(), symbol.clone());
 
         let cond_args: &Seg;
@@ -338,6 +367,7 @@ impl Symbol {
                             args: Args::None,
                             docs: format!("local argument to {}", f.arg_syms[n].clone()),
                             conditional_branches: false,
+                            ..Default::default()
                         },
                     ) {
                         holding_table.insert(f.arg_syms[n].clone(), old);
@@ -412,6 +442,26 @@ impl Symbol {
             docs: doc.clone(),
             conditional_branches: false,
             args, value,
+            ..Default::default()
+        }
+    }
+}
+
+impl Default for Symbol {
+    fn default() -> Symbol {
+        Symbol {
+            value: ValueType::Internal(
+                Rc::new(
+                    |_: &Seg, _: &mut SymTable| -> Result<Ctr, String> {
+                        unimplemented!()
+                    }
+                )
+            ),
+            name: String::new(),
+            docs: String::new(),
+            args: Args::None,
+            conditional_branches: false,
+            __generation: 0,
         }
     }
 }
@@ -427,6 +477,7 @@ pub fn call_lambda(
         docs: String::from("user defined lambda"),
         args: Args::Lazy(lam.arg_syms.len() as u128),
         value: ValueType::FuncForm(lam.clone()),
+        ..Default::default()
     };
 
     let args: &Seg;