some re-org

src/vcd/parse/combinator_atoms.rs

@@ -0,0 +1,70 @@
+use super::types::ParseResult;
+
+pub(super) fn digit(chr : u8) -> bool {
+    let zero = b'0' as u8;
+    let nine = b'9' as u8;
+
+    let between_zero_and_nine = (chr >= zero) && (nine >= chr);
+
+    return between_zero_and_nine
+}
+
+pub(super) fn take_until<'a>(word : &'a str, pattern : u8) -> ParseResult<'a> {
+    let mut new_start  = 0;
+
+    for chr in word.as_bytes() {
+        if (*chr == pattern) {
+            break
+        } 
+        else {
+            new_start += 1;
+        }
+    }
+
+    return 
+        ParseResult{
+            matched  : &word[0..new_start],
+            residual : &word[new_start..]
+        };
+
+}
+
+pub(super) fn take_while<'a>(word : &'a str, cond : fn(u8) -> bool) -> ParseResult<'a> {
+    let mut new_start  = 0;
+
+    for chr in word.as_bytes() {
+        if (cond(*chr)) {
+            new_start += 1;
+        } 
+        else {
+            break
+        }
+    }
+
+    return 
+        ParseResult{
+            matched  : &word[0..new_start],
+            residual : &word[new_start..]
+        };
+
+}
+
+pub(super) fn tag<'a>(word : &'a str, pattern : &'a str) -> ParseResult<'a> {
+    let lhs           = word.as_bytes().iter();
+    let rhs           = pattern.as_bytes();
+    let iter          = lhs.zip(rhs);
+    let mut new_start = 0;
+
+    let mut res = true;
+    for (c_lhs, c_rhs) in iter {
+        res = res && (c_lhs == c_rhs);
+        if !res {break}
+        new_start += 1;
+    }
+
+    return 
+        ParseResult{
+            matched  : &word[0..new_start],
+            residual : &word[new_start..]
+        };
+}