new parser, support exporttree, generally nicer code

1 files changed, 38 insertions, 0 deletions

diff --git a/src/parser.rs b/src/parser.rs
new file mode 100644
index 0000000..13cd22b
--- /dev/null
+++ b/src/parser.rs
@@ -0,0 +1,38 @@
+
+pub struct Parser<'a> {
+    buf: &'a str,
+    offset: usize
+}
+
+impl<'a> Parser<'a> {
+    pub fn new(buf: &'a str) -> Self {
+        Parser{buf, offset: 0}
+    }
+
+    pub fn next_word(&mut self) -> &'a str {
+        match self.buf[self.offset..].split_once(' ') {
+            Some((a,_)) => {
+                self.offset += a.len() + 1;
+                a
+            },
+            None => {
+                let res = &self.buf[self.offset..];
+                self.offset += self.buf.len() - self.offset;
+                res
+            }
+        }
+    }
+
+    pub fn remainder(&mut self) -> String {
+        let res = self.buf[self.offset..].to_owned();
+        self.offset = self.buf.len();
+        res
+    }
+
+    pub fn assert_end(&self) {
+        if self.buf.len() != self.offset {
+            println!("ERROR: failed parsing");
+            panic!()
+        }
+    }
+}