From 384f8252178be5aea33203040c17ca7606dd20ec Mon Sep 17 00:00:00 2001
From: Mitchell Paulus <paulusm14@gmail.com>
Date: Mon, 11 Nov 2024 16:57:23 -0600
Subject: [PATCH] Add split/join for strings

---
 doc/mshell.md                      |  6 ++-
 mshell-go/Evaluator.go             | 79 ++++++++++++++++++++++++++++++
 mshell/tests/split_join.msh        |  1 +
 mshell/tests/split_join.msh.stdout |  1 +
 4 files changed, 85 insertions(+), 2 deletions(-)
 create mode 100644 mshell/tests/split_join.msh
 create mode 100644 mshell/tests/split_join.msh.stdout

diff --git a/doc/mshell.md b/doc/mshell.md
index 0a0308c..c4cf2c7 100644
--- a/doc/mshell.md
+++ b/doc/mshell.md
@@ -28,6 +28,8 @@
 `str`: Convert to string
 `findReplace`: Find and replace in string. `findReplace (string string, string find, string replace -- string)`
 `lines`: Split string into list of string lines
+`split`: Split string into list of strings by delimiter, use `ws` literal or `"ws"` for whitespace. (string delimiter -- list)
+`join`: Join list of strings into a single string, (list delimiter -- string)
 
 ### List Functions
 
@@ -38,9 +40,9 @@
 
 ```mshell
 # Storing
-10 @a
+10 my_var!
 # Retrieving
-a!
+@my_var
 ```
 
 ## Process Substitution
diff --git a/mshell-go/Evaluator.go b/mshell-go/Evaluator.go
index 1d5977b..e64315e 100644
--- a/mshell-go/Evaluator.go
+++ b/mshell-go/Evaluator.go
@@ -386,6 +386,85 @@ func (state *EvalState) Evaluate(objects []MShellParseItem, stack *MShellStack,
                         return FailWithMessage(fmt.Sprintf("%d:%d: Cannot find-replace a %s.\n", t.Line, t.Column, obj1.TypeName()))
                     }
 
+                } else if t.Lexeme == "split" {
+                    delimiter, err := stack.Pop()
+                    if err != nil {
+                        return FailWithMessage(fmt.Sprintf("%d:%d: Cannot do 'split' operation on an empty stack.\n", t.Line, t.Column))
+                    }
+
+                    strLiteral, err := stack.Pop()
+                    if err != nil {
+                        return FailWithMessage(fmt.Sprintf("%d:%d: Cannot do 'split' operation on a stack with only one item.\n", t.Line, t.Column))
+                    }
+
+
+                    var delimiterStr string
+                    var strToSplit string
+
+                    switch delimiter.(type) {
+                    case *MShellString:
+                        delimiterStr = delimiter.(*MShellString).Content
+                    case *MShellLiteral:
+                        delimiterStr = delimiter.(*MShellLiteral).LiteralText
+                    default:
+                        return FailWithMessage(fmt.Sprintf("%d:%d: Cannot split with a %s.\n", t.Line, t.Column, delimiter.TypeName()))
+                    }
+
+                    switch strLiteral.(type) {
+                    case *MShellString:
+                        strToSplit = strLiteral.(*MShellString).Content
+                    case *MShellLiteral:
+                        strToSplit = strLiteral.(*MShellLiteral).LiteralText
+                    default:
+                        return FailWithMessage(fmt.Sprintf("%d:%d: Cannot split a %s.\n", t.Line, t.Column, strLiteral.TypeName()))
+                    }
+
+                    split := strings.Split(strToSplit, delimiterStr)
+                    newList := &MShellList { Items: make([]MShellObject, len(split)), StandardInputFile: "", StandardOutputFile: "", StdoutBehavior: STDOUT_NONE }
+                    for i, item := range split {
+                        newList.Items[i] = &MShellString { item }
+                    }
+                    stack.Push(newList)
+                } else if t.Lexeme == "join" {
+                    delimiter, err := stack.Pop()
+                    if err != nil {
+                        return FailWithMessage(fmt.Sprintf("%d:%d: Cannot do 'join' operation on an empty stack.\n", t.Line, t.Column))
+                    }
+
+                    list, err := stack.Pop()
+                    if err != nil {
+                        return FailWithMessage(fmt.Sprintf("%d:%d: Cannot do 'join' operation on a stack with only one item.\n", t.Line, t.Column))
+                    }
+
+                    var delimiterStr string
+                    var listItems []string
+
+                    switch delimiter.(type) {
+                    case *MShellString:
+                        delimiterStr = delimiter.(*MShellString).Content
+                    case *MShellLiteral:
+                        delimiterStr = delimiter.(*MShellLiteral).LiteralText
+                    default:
+                        return FailWithMessage(fmt.Sprintf("%d:%d: Cannot join with a %s.\n", t.Line, t.Column, delimiter.TypeName()))
+                    }
+
+                    switch list.(type) {
+                    case *MShellList:
+                        for _, item := range list.(*MShellList).Items {
+                            switch item.(type) {
+                            case *MShellString:
+                                listItems = append(listItems, item.(*MShellString).Content)
+                            case *MShellLiteral:
+                                listItems = append(listItems, item.(*MShellLiteral).LiteralText)
+                            default:
+                                return FailWithMessage(fmt.Sprintf("%d:%d: Cannot join a list with a %s inside (%s).\n", t.Line, t.Column, item.TypeName(), item.DebugString()))
+                            }
+                        }
+                    default:
+                        return FailWithMessage(fmt.Sprintf("%d:%d: Cannot join a %s.\n", t.Line, t.Column, list.TypeName()))
+                    }
+
+                    stack.Push(&MShellString { strings.Join(listItems, delimiterStr) })
                 } else if t.Lexeme == "lines" {
                     obj, err := stack.Pop()
                     if err != nil {
diff --git a/mshell/tests/split_join.msh b/mshell/tests/split_join.msh
new file mode 100644
index 0000000..0342f28
--- /dev/null
+++ b/mshell/tests/split_join.msh
@@ -0,0 +1 @@
+"cell1|cell2|cell3" "|" split ":" join wl
diff --git a/mshell/tests/split_join.msh.stdout b/mshell/tests/split_join.msh.stdout
new file mode 100644
index 0000000..4879c89
--- /dev/null
+++ b/mshell/tests/split_join.msh.stdout
@@ -0,0 +1 @@
+cell1:cell2:cell3