add split function

stdlib/stdlib.go

@@ -143,6 +143,13 @@ func GenFuncTable() ast.FuncTable {
             Args:           -1,
         },
 
+        "split": &ast.Function{
+            Function:   Split,
+            Name:     "split",
+            TimesCalled:    0,
+            Args:           2,
+        },
+
         "exit": &ast.Function{
             Function:  ExitShell,
             Name:         "exit",

stdlib/string.go

@@ -19,6 +19,7 @@ package stdlib
 
 import (
     "fmt"
+    "strings"
     "strconv"
     "gitlab.com/whom/shs/ast"
     "gitlab.com/whom/shs/log"
@@ -59,6 +60,47 @@ func StrCast(in *ast.Token, vt ast.VarTable, ft ast.FuncTable) *ast.Token {
     return res
 }
 
+/* Takes 2 arguments, a string and a delimiter
+ * returns a list of substrings found delimited by the delimiter from the parent string
+ * Filters out all empty segments between delimiters
+ *
+ * Example: (split "/path/to/file" "/") -> ("path" "to" "file")
+ */
+func Split(in *ast.Token, vt ast.VarTable, ft ast.FuncTable) *ast.Token {
+    in = in.Eval(ft, vt, false)
+    if in == nil || in.Tag != ast.STRING || in.Next == nil || in.Next.Tag != ast.STRING {
+        log.Log(log.ERR,
+            "Args must be two strings",
+            "split")
+        return nil
+    }
+
+    body := in.Value()
+    delim := in.Next.Value()
+    if len(body) < len(delim) {
+        log.Log(log.DEBUG,
+            "possibly mismatched args" +
+                "delimiter longer than body",
+            "split")
+    }
+
+    var res *ast.Token
+    builder := &res
+    strtoks := strings.Split(body, delim)
+    for _, i := range strtoks {
+        if i == "" {
+            continue
+        }
+
+        *builder = &ast.Token{Tag: ast.STRING}
+        (*builder).Set(i)
+        builder = &(*builder).Next
+    }
+
+    return res
+}
+
+
 /* Takes one arg, returns nil
  * Prints a string to stdout
  * Unquotes string so user can add escaped chars like \n, \t, etc