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-rw-r--r--third_party/rust/nom/tests/named_args.rs161
1 files changed, 161 insertions, 0 deletions
diff --git a/third_party/rust/nom/tests/named_args.rs b/third_party/rust/nom/tests/named_args.rs
new file mode 100644
index 0000000000..811b0a0dce
--- /dev/null
+++ b/third_party/rust/nom/tests/named_args.rs
@@ -0,0 +1,161 @@
+#[macro_use]
+extern crate nom;
+
+use nom::{
+ branch::alt,
+ sequence::{delimited, pair, preceded},
+ character::complete::{digit1 as digit, space0 as space},
+ bytes::complete::tag
+};
+
+// Parser definition
+
+use std::str;
+use std::str::FromStr;
+
+use self::Operator::*;
+
+enum Operator {
+ Slash,
+ Star,
+}
+
+impl Operator {
+ fn to_str(&self) -> &'static str {
+ match *self {
+ Slash => "/",
+ Star => "*",
+ }
+ }
+}
+
+// Parse the specified `Operator`.
+named_args!(operator(op: Operator) <&[u8], &[u8]>,
+ call!(tag(op.to_str()))
+);
+
+// We parse any expr surrounded by the tags `open_tag` and `close_tag`, ignoring all whitespaces around those
+named_args!(brackets<'a>(open_tag: &str, close_tag: &str) <&'a[u8], i64>,
+ call!(delimited(
+ space,
+ delimited(tag(open_tag), preceded(space, expr), preceded(space, tag(close_tag))),
+ space
+ ))
+);
+
+fn byte_slice_to_str<'a>(s: &'a[u8]) -> Result<&'a str, str::Utf8Error> {
+ str::from_utf8(s)
+}
+
+// We transform an integer string into a i64, ignoring surrounding whitespaces
+// We look for a digit suite, and try to convert it.
+// If either str::from_utf8 or FromStr::from_str fail,
+// we fallback to the brackets parser defined above
+named!(factor<&[u8], i64>, alt!(
+ map_res!(
+ map_res!(
+ call!(delimited(space, digit, space)),
+ byte_slice_to_str
+ ),
+ FromStr::from_str
+ )
+ | call!(brackets, "(", ")")
+ )
+);
+
+// We read an initial factor and for each time we find
+// a * or / operator followed by another factor, we do
+// the math by folding everything
+named!(term <&[u8], i64>, do_parse!(
+ init: factor >>
+ res: fold_many0!(
+ pair!(alt!(call!(operator, Star) | call!(operator, Slash)), factor),
+ init,
+ |acc, (op, val): (&[u8], i64)| {
+ if (op[0] as char) == '*' { acc * val } else { acc / val }
+ }
+ ) >>
+ (res)
+ )
+);
+
+named!(expr <&[u8], i64>, do_parse!(
+ init: term >>
+ res: fold_many0!(
+ call!(pair(alt((tag("+"), tag("-"))), term)),
+ init,
+ |acc, (op, val): (&[u8], i64)| {
+ if (op[0] as char) == '+' { acc + val } else { acc - val }
+ }
+ ) >>
+ (res)
+ )
+);
+
+#[test]
+fn factor_test() {
+ assert_eq!(
+ factor(&b"3"[..]),
+ Ok((&b""[..], 3))
+ );
+ assert_eq!(
+ factor(&b" 12"[..]),
+ Ok((&b""[..], 12))
+ );
+ assert_eq!(
+ factor(&b"537 "[..]),
+ Ok((&b""[..], 537))
+ );
+ assert_eq!(
+ factor(&b" 24 "[..]),
+ Ok((&b""[..], 24))
+ );
+}
+
+#[test]
+fn term_test() {
+ assert_eq!(
+ term(&b" 12 *2 / 3"[..]),
+ Ok((&b""[..], 8))
+ );
+ assert_eq!(
+ term(&b" 2* 3 *2 *2 / 3"[..]),
+ Ok((&b""[..], 8))
+ );
+ assert_eq!(
+ term(&b" 48 / 3/2"[..]),
+ Ok((&b""[..], 8))
+ );
+}
+
+#[test]
+fn expr_test() {
+ assert_eq!(
+ expr(&b" 1 + 2 "[..]),
+ Ok((&b""[..], 3))
+ );
+ assert_eq!(
+ expr(&b" 12 + 6 - 4+ 3"[..]),
+ Ok((&b""[..], 17))
+ );
+ assert_eq!(
+ expr(&b" 1 + 2*3 + 4"[..]),
+ Ok((&b""[..], 11))
+ );
+}
+
+#[test]
+fn parens_test() {
+ assert_eq!(
+ expr(&b" ( 2 )"[..]),
+ Ok((&b""[..], 2))
+ );
+ assert_eq!(
+ expr(&b" 2* ( 3 + 4 ) "[..]),
+ Ok((&b""[..], 14))
+ );
+ assert_eq!(
+ expr(&b" 2*2 / ( 5 - 1) + 3"[..]),
+ Ok((&b""[..], 4))
+ );
+}