add grassmudhorse

src/main.rs

@@ -0,0 +1,112 @@
+use err_derive::Error;
+
+#[derive(Debug, Error)]
+pub enum ParseError {
+    #[error(display = "error syntax: {:?}", _0)]
+    ErrorSyntax(String),
+}
+
+#[derive(Debug)]
+enum Instruction {
+    Push,
+    Dup,
+    CopyN,
+    Swap,
+    Pop,
+    PopN,
+    Add,
+    Sub,
+    Mul,
+    Div,
+    Mod,
+    Store,
+    Retrieve,
+    DefineLabel,
+    CallAtLabel,
+    GotoLabel,
+    GotoLabelE0,
+    GotoLabelL0,
+    ReturnCallAt,
+    End,
+    StdOutChar,
+    StdOutNum,
+    StdInChar,
+    StdInNum,
+}
+
+struct ParseChars {
+    index: usize,
+    chars: Vec<char>,
+}
+
+impl ParseChars {
+    fn next(&mut self) -> Option<char> {
+        let c = self.try_next();
+        if c.is_some() { self.index += 1; }
+        c
+    }
+
+    fn try_next(&self) -> Option<char> {
+        self.try_next_n(0_usize)
+    }
+
+    fn try_next_n(&self, nn: usize) -> Option<char> {
+        let i = self.index + nn;
+        if i >= self.chars.len() {
+            None
+        } else {
+            let c = self.chars[i];
+            Some(c)
+        }
+    }
+}
+
+const VALID_INSTRUCTION_CHARS: &str = "草泥马河蟹";
+
+fn main() {
+    let input = "草草草泥马 马草草草泥草草草草泥泥马 草马草 泥马草泥 草草草泥草泥草马 泥马草草 草草草泥马 泥草草草 草马草 草草草泥草泥泥马 泥草草泥 马泥草草泥草草草泥草泥马 马草马草泥草草草草泥泥马 马草草草泥草草草泥草泥马 草马马 马马马";
+
+    println!("{:?}", parse_lang(input));
+}
+
+fn parse_lang(lang: &str) -> Result<Vec<Instruction>, ParseError> {
+    let mut r = vec![];
+
+    let mut cs = ParseChars{ index: 0_usize, chars: lang.chars().filter(|c| {
+        VALID_INSTRUCTION_CHARS.chars().any(|vic| vic == *c)
+    }).collect(), };
+    while let Some(c) = cs.next() {
+        let nc = match cs.try_next() {
+            Some(nc) => nc, None => {
+                return Err(ParseError::ErrorSyntax(
+                    format!("Syntax error: after {} has no valid char", c)
+                ));
+            },
+        };
+        if c == '草' && nc == '草' { // Push
+            cs.next();
+            // todo parse
+            continue;
+        }
+        let nnc = match cs.try_next_n(1) {
+            Some(nc) => nc, None => {
+                return Err(ParseError::ErrorSyntax(
+                    format!("Syntax error: after {}{} has no valid char", c, nc)
+                ));
+            },
+        };
+        if c == '草' && nc == '马' || nnc == '草' { // Dup
+
+        }
+        let nnnc = match cs.try_next_n(2) {
+            Some(nc) => nc, None => {
+                return Err(ParseError::ErrorSyntax(
+                    format!("Syntax error: after {}{}{} has no valid char", c, nc, nnc)
+                ));
+            },
+        };
+    }
+
+    Ok(r)
+}
+