refactored ast tables, added eval method

ast/func_table.go

@@ -0,0 +1,70 @@
+/*   SHS: Syntactically Homogeneous Shell
+ *   Copyright (C) 2019  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 <https://www.gnu.org/licenses/>.
+ */
+
+package stdlib
+
+import (
+    "git.callpipe.com/aidan/shs/ast"
+)
+
+type Operation func(*Token) *Token
+
+type Function struct {
+    function    Operation
+    timesCalled int
+    args        int // TODO: Make this a list of expected types (TAGs)
+}
+
+type FuncTable map[string]*Function
+
+// TODO: Currently only checks arg list length
+func (Function f) ParseFunction(args *ast.Token) bool {
+    // HANDLE EXEC
+    if target.args < 0 {
+        return true
+    }
+
+    i := target.args
+    for iter := &args; *iter != nil; iter = &((*iter).next) {
+        i -= 1
+    }
+
+    if i != 0 {
+        // TODO: log error here
+        return false
+    }
+
+    return true
+}
+
+func (Function f) CallFunction(args *Token) *Token {
+    if !ParseFunction(f, args) {
+        return nil
+    }
+
+    f.timesCalled += 1
+    return f.function(args)
+}
+
+func (FuncTable table) GetFunction(arg string) *Function {
+    target, ok := table[arg]
+    if !ok {
+        return nil
+    }
+
+    return target
+}