Parsing `by hand', gui in separate module

1 files changed, 134 insertions, 0 deletions

diff --git a/src/parser.rs b/src/parser.rs
new file mode 100644
index 0000000..49ded9b
--- /dev/null
+++ b/src/parser.rs
@@ -0,0 +1,134 @@
+// #[macro_use]
+// extern crate nom;
+
+// use nom::*;
+
+use crate::game::*;
+
+fn parse_move(player: Player, mv: &str) -> Result<Action, String> {
+    let mut chars = mv.chars();
+
+    let c = chars.next();
+    if c.is_none() {
+        return Err(String::from("Empty string cannot be parsed."));
+    }
+
+    let dc = c.unwrap();
+    if (dc < '1') || ('9' < dc) {
+        return Err(String::from(
+            "Moves must begin with a digit in 1-8 indicating the number of drops.",
+        ));
+    }
+    let sum_drops = dc.to_digit(10).unwrap();
+
+    let c = chars.next();
+    if c.is_none() {
+        return Err(String::from("Moves must specify a stack position."));
+    }
+
+    let x = c.unwrap();
+    if (x < 'a') || (x > 'h') {
+        return Err(String::from(
+            "Moves must specify a position on the game board.",
+        ));
+    }
+    let x: u8 = x as u8 - 'a' as u8;
+
+    let c = chars.next();
+    if c.is_none() {
+        return Err(String::from("Moves must specify a stack position."));
+    }
+
+    let y = c.unwrap();
+    if (y < '1') || (y > '8') {
+        return Err(String::from(
+            "Moves must specify a position on the game board.",
+        ));
+    }
+    let y: u8 = (y.to_digit(10).unwrap() - 1) as u8;
+
+    let c = chars.next();
+    if c.is_none() {
+        return Err(String::from("Moves must specify a move direction."));
+    }
+
+    let c = c.unwrap();
+    let mut dir = Direction::Up;
+    match c {
+        '+' => dir = Direction::Up,
+        '-' => dir = Direction::Down,
+        '<' => dir = Direction::Left,
+        '>' => dir = Direction::Right,
+        _ => return Err(String::from("The valid directions are +,-,<, and >.")),
+    }
+
+    let mut drops: Vec<u8> = Vec::new();
+    for d in chars {
+        if let Some(u) = d.to_digit(10) {
+            if u > 9 {
+                return Err(String::from(
+                    "No more than 8 pieces may be dropped on a given square.",
+                ));
+            } else {
+                drops.push(u as u8)
+            }
+        } else {
+            return Err(String::from(
+                "A move must specify a number of pieces dropped for each square.",
+            ));
+        }
+    }
+
+    let sum = drops.iter().map(|&d| d as u32).sum::<u32>();
+    if sum != sum_drops {
+        return Err(format!(
+            "The move called for {} stones, but {} were dropped.",
+            sum_drops, sum
+        ));
+    }
+
+    Ok(Action::Move(player, Position { x: x, y: y }, dir, drops))
+}
+
+fn parse_place(player: Player, pl: &str) -> Result<Action, String> {
+    Ok(Action::Place(player, Position { x: 0, y: 0 }, Stone::Flat))
+}
+
+pub fn parse_action(player: Player, act: &str) -> Result<Action, String> {
+    if act
+        .chars()
+        .any(|c| c == '+' || c == '-' || c == '>' || c == '<')
+    {
+        parse_move(player, act)
+    } else {
+        parse_place(player, act)
+    }
+}
+
+// fn parse_move(mv: &str) -> Result<Action, Err<&str>> {
+//     one_of!("abcdefgh");
+//     Ok(Action::Place(
+//         Player::Black,
+//         Position { x: 0, y: 0 },
+//         Stone::Flat,
+//     ))
+// }
+
+// fn parse_place(pl: &str) -> Result<Action, Err<&str>> {
+//     Ok(Action::Place(
+//         Player::Black,
+//         Position { x: 0, y: 0 },
+//         Stone::Flat,
+//     ))
+// }
+
+// pub fn parse_action(act: &str) -> Result<Action, Err<&str>> {
+//     if act
+//         .chars()
+//         .any(|c| c == '+' || c == '-' || c == '>' || c == '<')
+//     {
+//         parse_move(act)
+//     } else {
+//         parse_place(act)
+//     }
+// }