Add initial codebase for ask_() functions

libimaginteraction/src/ask.rs

@@ -1 +1,64 @@
 // functions to ask the user for data, with crate:spinner
+
+use std::io::stdin;
+
+use regex::Regex;
+use ansi_term::Colour::*;
+
+/// Ask the user for a Yes/No answer. Optionally provide a default value. If none is provided, this
+/// keeps loop{}ing
+pub fn ask_bool(s: &str, default: Option<bool>) -> bool {
+    lazy_static! {
+        static ref R_YES: Regex = Regex::new(r"^[Yy]$").unwrap();
+        static ref R_NO: Regex  = Regex::new(r"^[Nn]$").unwrap();
+    }
+
+    loop {
+        ask_question(s, false);
+        if match default { Some(s) => s, _ => true } {
+            println!(" [Yn]: ");
+        } else {
+            println!(" [yN]: ");
+        }
+
+        let mut s = String::new();
+        let _     = stdin().read_line(&mut s);
+
+        if R_YES.is_match(&s[..]) {
+            return true
+        } else if R_NO.is_match(&s[..]) {
+            return false
+        } else {
+            if default.is_some() {
+                return default.unwrap();
+            }
+
+            // else again...
+        }
+    }
+}
+
+pub fn ask_uint(s: &str) -> u64 {
+    unimplemented!()
+}
+
+pub fn ask_string(s: &str) -> String {
+    unimplemented!()
+}
+
+pub fn ask_enum<E: From<String>>(s: &str) -> E {
+    unimplemented!()
+}
+
+/// Helper function to print a imag question string. The `question` argument may not contain a
+/// trailing questionmark.
+///
+/// The `nl` parameter can be used to configure whether a newline character should be printed
+pub fn ask_question(question: &str, nl: bool) {
+    if nl {
+        println!("[imag]: {}?", Yellow.paint(question));
+    } else {
+        print!("[imag]: {}?", Yellow.paint(question));
+    }
+}
+