implementations for quote and eval

Readme.org

@@ -301,23 +301,43 @@ This contains any executable target of this project. Notably the main shell file
 Note: this section will not show the status of each item unless you are viewing it with a proper orgmode viewer.
 Note: this section only tracks the state of incomplete TODO items. Having everything on here would be cluttered.
 
-*** TODO Syntax improvements
-**** WONTDO implicit single quote
-**** TODO :symbol syntax
-**** TODO Update Tests
-**** TODO Update Makefile documentation
 *** TODO Quote function
+    (just needs tests and stl entries)
 *** TODO Eval function
+    (just needs tests and stl entries)
+*** TODO list contains via circuit
+*** TODO Lambda hack
+BAD IDEAS
+- lambda function can use illegal name parameter for symbol names, guaranteeing non collision in symbol table
+- add some incrementing variable to avoid lambdas colliding with lambdas
+- custom drop implementation for Ctr that only overrides Symbol, checks for illegal name conventions, and yeets from symtable
+  (how do we get the sym table into the drop impl)
+- when repl loops, clear lambdas out of the symtable
+  (shit hack and will only work for very simple cases. highly not ideal)
+GOOD IDEA
+- could implement a new Ctr type to encapsulate function and args
+  - would need a new case in store for when bound to a var but honestly store should be rewritten
+  - would need a case in eval that mirrors the function call case
+
+DOCUMENTATION:
+- let case for creating and applying a lambda
+*** TODO Map function
+- DOCUMENTATION + TEST:
+  apply a lambda to a list
+*** TODO Reduce function
 *** TODO Input function
 *** TODO Lex function
 *** TODO Read function (Input + Lex)
+*** TODO Caps function (list functions in table)
+*** TODO Default prompt says "<minimum shell> LAMBDA:"
 *** TODO Load (load a script) function
 Pull/Refactor the logic out of the configure functions.
 Optionally return a list of new variables and/or functions?
 Will need a concatenate function for tables
 *** TODO Main shell calls Load function on arg and exits
+*** TODO Ship a relish-based stdlib
 *** TODO FINISH DOCUMENTATION
-*** TODO Shell module
+*** TODO Shell module-
 **** TODO only loadable via POSIX config var
 Overload Load function to call a binary too
 **** TODO arg processor because these are control flow

src/stl/decl.rs

@@ -20,6 +20,26 @@ use crate::segment::{Ctr, Seg};
 use crate::sym::{Args, SymTable, Symbol, UserFn, ValueType};
 use std::env;
 
+pub const QUOTE_DOCSTRING: &str = "takes a single unevaluated tree and returns it as it is: unevaluated.";
+
+pub fn quote_callback(ast: &Seg, _syms: &mut SymTable) -> Result<Ctr, String> {
+    if ast.len() > 1 {
+        Err("do not quote more than one thing at a time".to_string())
+    } else {
+        Ok(Ctr::Seg(ast.clone()))
+    }
+}
+
+pub const EVAL_DOCSTRING: &str = "takes an unevaluated argument and evaluates it.";
+
+pub fn eval_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, String> {
+    if ast.len() > 1 {
+        Err("do not quote more than one thing at a time".to_string())
+    } else {
+        Ok(*eval(ast, syms)?.clone())
+    }
+}
+
 pub const HELP_DOCSTRING: &str = "prints help text for a given symbol. Expects only one argument.";
 
 pub fn help_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, String> {