1 files changed, 84 insertions, 0 deletions
diff --git a/vendor/time-macros/src/format_description/parse.rs b/vendor/time-macros/src/format_description/parse.rs
new file mode 100644
index 000000000..19c7bf608
--- /dev/null
+++ b/vendor/time-macros/src/format_description/parse.rs
@@ -0,0 +1,84 @@
+use proc_macro::Span;
+
+use crate::format_description::component::{Component, NakedComponent};
+use crate::format_description::error::InvalidFormatDescription;
+use crate::format_description::{helper, modifier, FormatItem};
+use crate::Error;
+
+struct ParsedItem<'a> {
+    item: FormatItem<'a>,
+    remaining: &'a [u8],
+}
+
+fn parse_component(mut s: &[u8], index: &mut usize) -> Result<Component, InvalidFormatDescription> {
+    s = helper::consume_whitespace(s, index);
+
+    let component_index = *index;
+    let whitespace_loc = s
+        .iter()
+        .position(u8::is_ascii_whitespace)
+        .unwrap_or(s.len());
+    *index += whitespace_loc;
+    let component_name = &s[..whitespace_loc];
+    s = &s[whitespace_loc..];
+    s = helper::consume_whitespace(s, index);
+
+    Ok(NakedComponent::parse(component_name, component_index)?
+        .attach_modifiers(modifier::Modifiers::parse(component_name, s, index)?))
+}
+
+fn parse_literal<'a>(s: &'a [u8], index: &mut usize) -> ParsedItem<'a> {
+    let loc = s.iter().position(|&c| c == b'[').unwrap_or(s.len());
+    *index += loc;
+    ParsedItem {
+        item: FormatItem::Literal(&s[..loc]),
+        remaining: &s[loc..],
+    }
+}
+
+fn parse_item<'a>(
+    s: &'a [u8],
+    index: &mut usize,
+) -> Result<ParsedItem<'a>, InvalidFormatDescription> {
+    if let [b'[', b'[', remaining @ ..] = s {
+        *index += 2;
+        return Ok(ParsedItem {
+            item: FormatItem::Literal(b"["),
+            remaining,
+        });
+    };
+
+    if s.starts_with(b"[") {
+        if let Some(bracket_index) = s.iter().position(|&c| c == b']') {
+            *index += 1; // opening bracket
+            let ret_val = ParsedItem {
+                item: FormatItem::Component(parse_component(&s[1..bracket_index], index)?),
+                remaining: &s[bracket_index + 1..],
+            };
+            *index += 1; // closing bracket
+            Ok(ret_val)
+        } else {
+            Err(InvalidFormatDescription::UnclosedOpeningBracket { index: *index })
+        }
+    } else {
+        Ok(parse_literal(s, index))
+    }
+}
+
+pub(crate) fn parse(mut s: &[u8], span: Span) -> Result<Vec<FormatItem<'_>>, Error> {
+    let mut compound = Vec::new();
+    let mut loc = 0;
+
+    while !s.is_empty() {
+        let ParsedItem { item, remaining } =
+            parse_item(s, &mut loc).map_err(|error| Error::InvalidFormatDescription {
+                error,
+                span_start: Some(span),
+                span_end: Some(span),
+            })?;
+        s = remaining;
+        compound.push(item);
+    }
+
+    Ok(compound)
+}