Initial public release of Warp.

Repo-Sync-Origin: warpdotdev/warp-internal@12af1d983b

crates/handlebars/src/lib.rs

@@ -0,0 +1,90 @@
+pub mod parser;
+
+use parser::{ParsedArgumentResult, ParsedArgumentsIterator};
+use std::collections::{HashMap, HashSet};
+
+pub fn get_arguments(template: &str) -> Vec<String> {
+    let mut char_to_byte: Vec<usize> = template
+        .char_indices()
+        .map(|(byte_idx, _)| byte_idx)
+        .collect();
+    char_to_byte.push(template.len());
+
+    ParsedArgumentsIterator::new(template.chars())
+        .filter_map(|parsed| {
+            if let ParsedArgumentResult::Valid { .. } = parsed.result() {
+                let name_range = parsed.chars_range();
+
+                if name_range.start >= 2 {
+                    let name_start_byte = char_to_byte[name_range.start];
+                    let name_end_byte = char_to_byte[name_range.end];
+                    let name = template[name_start_byte..name_end_byte].to_string();
+
+                    Some(name)
+                } else {
+                    None
+                }
+            } else {
+                None
+            }
+        })
+        .collect::<HashSet<String>>()
+        .into_iter()
+        .collect()
+}
+
+pub fn render_template(template: &str, context: &HashMap<String, String>) -> String {
+    // Map char indices to byte indices for slicing.
+    let mut char_to_byte: Vec<usize> = template
+        .char_indices()
+        .map(|(byte_idx, _)| byte_idx)
+        .collect();
+    char_to_byte.push(template.len());
+
+    let mut out = String::with_capacity(template.len());
+    let mut cursor_byte = 0usize;
+
+    for parsed in ParsedArgumentsIterator::new(template.chars()) {
+        if let ParsedArgumentResult::Valid { .. } = parsed.result() {
+            let name_range = parsed.chars_range();
+            // The iterator yields only valid unescaped args without whitespace; the
+            // braces are not included in the returned range. For valid args, there
+            // must be exactly two braces on each side.
+            if name_range.start >= 2 {
+                let placeholder_start_char = name_range.start - 2;
+                let placeholder_end_char = name_range.end + 2; // exclusive
+
+                let start_byte = char_to_byte[placeholder_start_char];
+                let name_start_byte = char_to_byte[name_range.start];
+                let name_end_byte = char_to_byte[name_range.end];
+                let end_byte = char_to_byte[placeholder_end_char];
+
+                // Append unchanged prefix
+                if cursor_byte < start_byte {
+                    out.push_str(&template[cursor_byte..start_byte]);
+                }
+
+                let var_name = &template[name_start_byte..name_end_byte];
+                if let Some(value) = context.get(var_name) {
+                    out.push_str(value);
+                } else {
+                    // If no value provided, keep original placeholder
+                    out.push_str(&template[start_byte..end_byte]);
+                }
+
+                cursor_byte = end_byte;
+            }
+        }
+    }
+
+    // Append suffix
+    if cursor_byte < template.len() {
+        out.push_str(&template[cursor_byte..]);
+    }
+
+    out
+}
+
+#[cfg(test)]
+#[path = "lib_test.rs"]
+mod tests;