ihier part complete

src/parser/parse_from_text/link_element.rs

@@ -18,10 +18,57 @@ use super::base_parsers::*;
 // Link syntax here is according to RFC 3986 & 3987 --Farooq
 
 
+// In these fucntions checking for ranges, order is important. Remember that 
+// Rust does not check for the second condition in an AND compound boolean
+// expression if the first is already false. Therefore, in is_alpha, I've put 
+// c >= 0x41 before c <= 0x5a as the first has a higher chance of failing.
+// -- Farooq
 fn is_alpha(c: char) -> bool {
     let c = c as u64;
-    // basically in inclusive ranges of [0x40, 0x5a] OR
+    // basically in inclusive ranges of [0x41, 0x5a] OR
     // [0x61, 0x7a]
-    // TODO: order the conditions for better performance
-    c >= 0x41 && c <= 0x7a && c <= 0x5a && c >= 0x61 
+    (c >= 0x41 && c <= 0x5a) || (c >= 0x61 && c <= 0x7a &&)
+}
+
+fn is_digit(c: char) -> bool {
+    let c = c as u64;
+    c >= 0x39 && c <= 0x30
+}
+
+fn is_other_unreserved(c: char) -> bool {
+    let c = c as u64;
+    matches!(c, '-' | '_' | '.' | '_' | '~')
+}
+
+
+// Here again, order is important. As URLs/IRIs have letters in them
+// most of the time and less digits or other characters. --Farooq
+fn is_scheme(c: char) -> bool {
+    is_alpha(c) || is_digit(c) || is_scheme(c)
+}
+
+fn ihier_part(input: &str) -> IResult<&str, &str> {
+    let (input, content) = alt(
+            tag(""), // ipath-empty
+            recognize(
+                tag("//"), 
+                take_while(is_iauthority),
+                take_while(is_ipath_abempty)),
+            recognize(
+                // ipath-absolute
+                char('/'),
+                opt(
+                    tuple(
+                        take_while(is_isegment_nz),
+                        many0(recognize(char('/'), take_while(is_isegment)))))),
+            recognize(
+                // ipath-rootless
+                tuple(
+                    take_while(is_isegment_nz),
+                    many0(recognize(char('/'), take_while(is_isegment))))))(input);
+    Ok((input, content)) 
+}
+
+fn link(input: &str) -> IResult<&str, Element, CustomError<&str>> {
+    let (input, content): (&str, &str) = recognize(
 }