integrate environment variables with vartable

ast/var_table.go

@@ -17,17 +17,42 @@
 
 package ast
 
+import (
+    "os"
+    "strings"
+    "git.callpipe.com/aidan/shs/log"
+)
+
 type VarTable *map[string]*Token
 
 func GetVar(arg string, vt VarTable) *Token {
     val, ok := (*vt)[arg]
     if !ok {
+        e := os.Getenv(arg)
+        if e != "" {
+            t := &Token{Inner: e}
+            if StrIsNumber(e) {
+                t.Tag = NUMBER
+            } else {
+                t.Tag = STRING
+            }
+
+            SetVar(arg, t, vt)
+            return t
+        }
         return nil
     }
-
     return val
 }
 
+// TODO: Document me :)
+func SetVar(variable string, value *Token, vt VarTable) {
+    (*vt)[variable] = value
+    if value.Tag == NUMBER || value.Tag == STRING {
+        os.Setenv(variable, value.Inner.(string))
+    }
+}
+
 // Library represents variables defined in inner scope
 // It is assumed library is ordered from innermost scope to outermost scope
 func GetVarFromTables(arg string, library []VarTable) *Token {
@@ -43,3 +68,29 @@ func GetVarFromTables(arg string, library []VarTable) *Token {
 
     return res
 }
+
+func InitVarTable(table VarTable) {
+    for _, val := range os.Environ() {
+        variable := strings.Split(val, "=")
+        t := &Token{Inner: variable[1]}
+        if StrIsNumber(variable[1]) {
+            t.Tag = NUMBER
+        } else {
+            t.Tag = STRING
+        }
+
+        SetVar(variable[0], t, table)
+    }
+}
+
+// Dont do this on var tables youve already called InitVarTable on.... please....
+// This will pull currently contained variables OUT of the operating env
+func DeleteVarTable(table VarTable) {
+    for key, _ := range (*table) {
+        // from what I can tell, theres not much we can do if this fails
+        err := os.Unsetenv(key)
+        if err != nil {
+            log.Log(log.DEBUG, "Failed to remove " + key + " from env: " + err.Error(), "vartable")
+        }
+    }
+}