significant refactor and simplification

src/stl.rs

@@ -0,0 +1,118 @@
+/* relish: versatile lisp shell
+ * Copyright (C) 2021 Aidan Hahn
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+use crate::segment::{Ctr, Seg, Type};
+use crate::eval::eval;
+use crate::sym::{SYM_TABLE, Symbol, ValueType, Args, UserFn};
+use std::env;
+
+/*
+// the stdlib var export function with env_sync on
+static LIB_STORE_ENV: Symbol = Symbol {
+    name: String::from("export"),
+    args: Args::Lazy(2),
+    value: ValueType::Internal(Box::new( |ast: &Seg| -> Ctr {
+        _store_callback(ast, true)
+    },
+    )),
+    has_undefined_symbols: false,
+};
+
+// the stdlib var export function with env_sync off
+pub static LIB_STORE_NO_ENV: Symbol = Symbol {
+    name: String::from("export"),
+    args: Args::Lazy(2),
+    value: ValueType::Internal(Box::new( |ast: &Seg| -> Ctr {
+        _store_callback(ast, false)
+    },
+    )),
+    has_undefined_symbols: false,
+};*/
+
+// TODO : declare function if arg list is long enough
+fn _store_callback (ast: &Seg, env_cfg: bool) -> Ctr {
+    let mut table_handle = SYM_TABLE.lock().unwrap();
+    let is_var = ast.len() == 2;
+    if let Ctr::Symbol(ref identifier) = *ast.car {
+        match &*ast.cdr {
+            Ctr::Seg(data_tree) if is_var => match eval(&Box::new(data_tree), true, true) {
+                Ok(seg) => if let Ctr::Seg(ref val) = *seg {
+                    table_handle.insert(identifier.clone(), Symbol{
+                        value: ValueType::VarForm(val.car.clone()),
+                        name: identifier.clone(),
+                        args: Args::None,
+                        has_undefined_symbols: false,
+                    });
+                    if env_cfg {
+                        env::set_var(identifier.clone(), val.car.to_string());
+                    }
+                } else {
+                    eprintln!("impossible args to export")
+                },
+                Err(e) => eprintln!("couldnt eval symbol: {}", e),
+            },
+            Ctr::Seg(data_tree) if !is_var => {
+                if let Ctr::Seg(ref args) = *data_tree.car {
+                    let mut arg_list = vec![];
+                    if !args.circuit(&mut |c: &Ctr| -> bool {
+                        if let Ctr::Symbol(ref arg) = c {
+                            arg_list.push(arg.clone());
+                            true
+                        } else {
+                            false
+                        }
+                    }) {
+                        eprintln!("all arguments defined for function must be of type symbol");
+                        return Ctr::None;
+                    };
+
+                    if let Ctr::Seg(ref bodies) = *data_tree.cdr {
+                        table_handle.insert(identifier.clone(), Symbol{
+                            value: ValueType::FuncForm(UserFn{
+                                ast: Box::new(bodies.clone()),
+                                arg_syms: arg_list.clone(),
+                            }),
+                            name: identifier.clone(),
+                            args: Args::Strict(arg_list
+                                               .into_iter()
+                                               .map(Type::from)
+                                               .collect()),
+                            has_undefined_symbols: false,
+                        });
+                    } else {
+                        eprintln!("expected one or more function bodies in function definition");
+                        return Ctr::None;
+                    }
+                } else {
+                    eprintln!("expected list of arguments in function definition");
+                    return Ctr::None;
+                }
+            }
+            Ctr::None => {
+                table_handle.remove(&identifier.to_string());
+                if env_cfg {
+                    env::remove_var(identifier);
+                }
+            },
+            _ =>  eprintln!("args not in standard form"),
+        }
+    } else {
+        eprintln!("first argument to export must be a symbol");
+    }
+    Ctr::None
+}
+