Add alias support and update help func output to include it.

README.md

@@ -34,9 +34,9 @@ fn print_information(command: CommandArc, args: List[String]) -> None:
 
 
 fn get_cat_fact(command: CommandArc, args: List[String]) -> Error:
-    var flags = command[].get_all_flags()[]
+    var flags = command[].flags[]
     var lover = flags.get_as_bool("lover")
-    if lover and lover.value():
+    if lover and lover.value()[]:
         print("Hello fellow cat lover!")
 
     try:
@@ -54,7 +54,7 @@ fn get_cat_fact(command: CommandArc, args: List[String]) -> Error:
             if not count:
                 return Error("Count flag was not found.")
             var body = response.json()
-            for i in range(count.value()):
+            for i in range(count.value()[]):
                 print(body[i]["text"])
         else:
             return Error("Request failed!")
@@ -98,8 +98,8 @@ fn init() -> None:
         description="Get some cat facts!",
         erroring_run=get_cat_fact,
     )
-    cat_command.flags.add_int_flag[name="count", shorthand="c", usage="Number of facts to get."]()
-    cat_command.flags.add_bool_flag[name="lover", shorthand="l", usage="Are you a cat lover?"]()
+    cat_command.add_int_flag(name="count", shorthand="c", usage="Number of facts to get.")
+    cat_command.add_bool_flag(name="lover", shorthand="l", usage="Are you a cat lover?")
 
     var dog_command = Command(
         name="dog",
@@ -116,7 +116,6 @@ fn init() -> None:
 fn main() -> None:
     init()
 
-
 ```
 
 Start by navigating to the `nested` example directory.
@@ -201,7 +200,11 @@ Usage information will be printed the console by passing the `--help` flag.
 
 - Add find suggestion logic to `Command` struct.
 - Enable required flags.
+- Add flag groups and mutually exclusive flags.
+- Add subcommand groups.
+- Enable usage function to return the results of a usage function upon calling wrong functions or commands.
 - Replace print usage with writers to enable stdout/stderr/file writing.
+- Update default help command to improve available commands and flags section.
 
 ### Improvements
 

examples/aliases/root.mojo

@@ -0,0 +1,30 @@
+from memory._arc import Arc
+from prism import Flag, Command, CommandArc
+from prism.vector import to_string
+
+
+fn test(command: CommandArc, args: List[String]) -> None:
+    print("Pass tool, object, or thing as a subcommand!")
+
+
+fn tool_func(command: CommandArc, args: List[String]) -> None:
+    print("My tool!")
+
+
+fn init() -> None:
+    var root_command = Command(
+        name="my",
+        description="This is a dummy command!",
+        run=test,
+    )
+
+    var tool_command = Command(
+        name="tool", description="This is a dummy command!", run=tool_func, aliases=List[String]("object", "thing")
+    )
+
+    root_command.add_command(tool_command)
+    root_command.execute()
+
+
+fn main() -> None:
+    init()

prism/command.mojo

@@ -24,28 +24,32 @@ fn get_args_as_list() -> List[String]:
 
 fn default_help(command: Arc[Command]) -> String:
     """Prints the help information for the command."""
-    var cmd = command[]
     var builder = StringBuilder()
-    _ = builder.write_string(cmd.description)
-    _ = builder.write_string("\n\n")
+    _ = builder.write_string(command[].description)
+
+    if command[].aliases:
+        _ = builder.write_string("\n\nAliases:")
+        _ = builder.write_string(sprintf("\n  %s", to_string(command[].aliases)))
 
     # Build usage statement arguments depending on the command's children and flags.
-    var full_command = cmd._full_command()
-    _ = builder.write_string(sprintf("Usage:\n  %s%s", full_command, String(" [args]")))
-    if len(cmd.children) > 0:
+    var full_command = command[]._full_command()
+    _ = builder.write_string(sprintf("\n\nUsage:\n  %s%s", full_command, String(" [args]")))
+    if len(command[].children) > 0:
         _ = builder.write_string(" [command]")
-    if len(cmd.flags[]) > 0:
+    if len(command[].flags[]) > 0:
         _ = builder.write_string(" [flags]")
 
-    _ = builder.write_string("\n\nAvailable commands:\n")
-    for child in cmd.children:
-        _ = builder.write_string(sprintf("  %s\n", str(child[][])))
+    if command[].children:
+        _ = builder.write_string("\n\nAvailable commands:\n")
+        for child in command[].children:
+            _ = builder.write_string(sprintf("  %s\n", str(child[][])))
 
-    _ = builder.write_string("\nAvailable flags:\n")
-    for flag in cmd.flag_list():
-        _ = builder.write_string(sprintf("  -%s, --%s    %s\n", flag[][].shorthand, flag[][].name, flag[][].usage))
+    if command[].flag_list():
+        _ = builder.write_string("\n\nAvailable flags:\n")
+        for flag in command[].flag_list():
+            _ = builder.write_string(sprintf("  -%s, --%s    %s\n", flag[][].shorthand, flag[][].name, flag[][].usage))
 
-    _ = builder.write_string(sprintf('Use "%s [command] --help" for more information about a command.', full_command))
+    _ = builder.write_string(sprintf('\nUse "%s [command] --help" for more information about a command.', full_command))
     return str(builder)
 
 
@@ -70,7 +74,7 @@ fn parse_command_from_args(start: Command) -> (Command, List[String]):
 
     for arg in args:
         for command_ref in children:
-            if command_ref[][].name == arg[]:
+            if command_ref[][].name == arg[] or contains(command_ref[][].aliases, arg[]):
                 command = command_ref[][]
                 children = command.children
                 leftover_args_start_index += 1
@@ -100,12 +104,19 @@ struct Command(CollectionElement):
         erroring_run: The function to run when the command is executed that returns an error.
         erroring_pre_run: The function to run before the command is executed that returns an error.
         erroring_post_run: The function to run after the command is executed that returns an error.
+        persisting_pre_run: The function to run before the command is executed. This persists to children.
+        persisting_post_run: The function to run after the command is executed. This persists to children.
+        persisting_erroring_pre_run: The function to run before the command is executed that returns an error. This persists to children.
+        persisting_erroring_post_run: The function to run after the command is executed that returns an error. This persists to children.
         help: The function to generate help text for the command.
     """
 
     var name: String
     var description: String
 
+    # Aliases that can be used instead of the first word in name.
+    var aliases: List[String]
+
     # Generates help text.
     var help: HelpFunction
 
@@ -145,6 +156,7 @@ struct Command(CollectionElement):
         inout self,
         name: String,
         description: String,
+        aliases: List[String] = List[String](),
         valid_args: List[String] = List[String](),
         run: Optional[CommandFunction] = None,
         pre_run: Optional[CommandFunction] = None,
@@ -163,6 +175,7 @@ struct Command(CollectionElement):
 
         self.name = name
         self.description = description
+        self.aliases = aliases
 
         self.help = help
 
@@ -200,6 +213,7 @@ struct Command(CollectionElement):
         name: String,
         description: String,
         arg_validator: ArgValidator,
+        aliases: List[String] = List[String](),
         valid_args: List[String] = List[String](),
         run: Optional[CommandFunction] = None,
         pre_run: Optional[CommandFunction] = None,
@@ -218,6 +232,7 @@ struct Command(CollectionElement):
 
         self.name = name
         self.description = description
+        self.aliases = aliases
 
         self.help = help
 
@@ -250,6 +265,7 @@ struct Command(CollectionElement):
     fn __copyinit__(inout self, existing: Self):
         self.name = existing.name
         self.description = existing.description
+        self.aliases = existing.aliases
 
         self.help = existing.help
 
@@ -279,6 +295,7 @@ struct Command(CollectionElement):
     fn __moveinit__(inout self, owned existing: Self):
         self.name = existing.name^
         self.description = existing.description^
+        self.aliases = existing.aliases^
 
         self.help = existing.help
 
@@ -306,7 +323,7 @@ struct Command(CollectionElement):
         self.parent = existing.parent^
 
     fn __str__(self) -> String:
-        return "(Name: " + self.name + ", Description: " + self.description + ")"
+        return sprintf("(Name: %s, Description: %s)", self.name, self.description)
 
     fn __repr__(inout self) -> String:
         var parent_name: String = ""

run_examples.sh

@@ -5,6 +5,7 @@ mkdir ./temp
 mojo package prism -I ./external -o ./temp/prism.mojopkg
 
 echo -e "Building binaries for all examples...\n"
+mojo build examples/aliases/root.mojo -o temp/aliases
 mojo build examples/hello_world/root.mojo -o temp/hello_world
 mojo build examples/nested/nested.mojo -o temp/nested
 mojo build examples/printer/printer.mojo -o temp/printer
@@ -15,6 +16,7 @@ mkdir -p temp/examples/read_csv/ && cp examples/read_csv/file.csv temp/examples/
 
 echo -e "Executing examples...\n"
 cd temp
+./aliases my thing
 ./hello_world say hello
 ./nested get cat --count 5 -l
 ./printer "sample-text" --formatting=underline