1 files changed, 122 insertions, 0 deletions
diff --git a/mingling_picker/src/flag.rs b/mingling_picker/src/flag.rs
new file mode 100644
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+++ b/mingling_picker/src/flag.rs
@@ -0,0 +1,122 @@
+use crate::Pickable;
+use std::marker::PhantomData;
+
+/// Represents a constraint definition for a parameter selection.
+///
+/// This structure describes the constraints that a command-line parameter (Picker parameter item)
+/// should satisfy, including its full name list (with aliases), short name form, and whether it is
+/// positional.
+///
+/// # Field Descriptions
+///
+/// - `full`: Full name or alias list. For example, `["config", "cfg"]` means the parameter can be
+///   matched with either `--config` or `--cfg`. Must contain at least one non-empty string.
+///
+/// - `short`: Short name (single character). For example, `Some('c')` means it can be passed using
+///   the `-c` form. If set to `None`, the short name form is not supported.
+///
+/// - `positional`: Whether the parameter is positional (i.e., an argument without a flag).
+///   - `true`: The parameter is positional; it is matched by its position in the command line rather
+///     than by a `--name` or `-n` flag.
+///   - `false`: The parameter is a named (flag-based) parameter.
+///
+/// - `_type`: PhantomData to hold the type parameter.
+#[derive(Default, Clone, Copy)]
+pub struct PickerFlag<'a, Type>
+where
+    Type: Default + Pickable,
+{
+    /// Full name, may include variant names (aliases), e.g., `["config", "cfg"]`.
+    pub full: &'a [&'a str],
+
+    /// Short name, e.g., `'c'`.
+    pub short: Option<char>,
+
+    /// Whether the parameter is positional (no flag, matched by position).
+    pub positional: bool,
+
+    /// PhantomData to hold the type parameter.
+    pub internal_type: PhantomData<Type>,
+}
+
+impl<'a, Type> PickerFlag<'a, Type>
+where
+    Type: Default + Pickable,
+{
+    /// Creates a new `PickerFlag` with the provided parameters.
+    pub fn new(full: &'a [&'a str], short: Option<char>, positional: bool) -> Self {
+        Self {
+            full,
+            short,
+            positional,
+            internal_type: PhantomData,
+        }
+    }
+
+    /// Returns the full name list (including aliases).
+    pub fn full(&self) -> &'a [&'a str] {
+        self.full
+    }
+
+    /// Returns the short name, if any.
+    pub fn short(&self) -> Option<char> {
+        self.short
+    }
+
+    /// Returns whether the parameter is positional.
+    ///
+    /// If `full` is empty or `short` is `None`, the parameter is considered positional
+    /// regardless of the stored value.
+    pub fn is_positional(&self) -> bool {
+        if self.full.is_empty() && self.short.is_none() {
+            true
+        } else {
+            self.positional
+        }
+    }
+
+    /// Sets the full name list.
+    pub fn set_full(&mut self, full: &'a [&'a str]) {
+        self.full = full;
+    }
+
+    /// Sets the short name.
+    pub fn set_short(&mut self, short: Option<char>) {
+        self.short = short;
+    }
+
+    /// Sets whether the parameter is positional.
+    pub fn set_positional(&mut self, positional: bool) {
+        self.positional = positional;
+    }
+
+    /// Sets the full name list and returns self.
+    pub fn with_full(mut self, full: &'a [&'a str]) -> Self {
+        self.full = full;
+        self
+    }
+
+    /// Clears the full name list (sets it to an empty slice) and returns self.
+    pub fn without_full(mut self) -> Self {
+        self.full = &[];
+        self
+    }
+
+    /// Sets the short name to the given character and returns self.
+    pub fn with_short(mut self, short: char) -> Self {
+        self.short = Some(short);
+        self
+    }
+
+    /// Clears the short name (sets it to None) and returns self.
+    pub fn without_short(mut self) -> Self {
+        self.short = None;
+        self
+    }
+
+    /// Sets whether the parameter is positional and returns self.
+    pub fn with_positional(mut self, positional: bool) -> Self {
+        self.positional = positional;
+        self
+    }
+}