Add Svelte docs site and WASM playground

crates/decodal-wasm/src/lib.rs

@@ -0,0 +1,96 @@
+use decodal_core::{Data, EmptyLoader, Engine};
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen]
+pub fn evaluate(source: &str) -> String {
+    match evaluate_inner(source) {
+        Ok(output) => format!("{{\"ok\":true,\"output\":{}}}", json_string(&output)),
+        Err(error) => format!("{{\"ok\":false,\"error\":{}}}", json_string(&error)),
+    }
+}
+
+fn evaluate_inner(source: &str) -> Result<String, String> {
+    let mut engine = Engine::new(EmptyLoader);
+    let module = engine
+        .add_root_source("playground", "playground", source)
+        .map_err(format_diagnostic)?;
+    let value = engine.eval_module(module).map_err(format_diagnostic)?;
+    let data = engine.materialize(&value).map_err(format_diagnostic)?;
+    Ok(format_data(&data, 0))
+}
+
+fn format_diagnostic(diagnostic: decodal_core::Diagnostic) -> String {
+    format!(
+        "{:?} at {}:{}..{}: {}",
+        diagnostic.kind,
+        diagnostic.span.source.0,
+        diagnostic.span.start,
+        diagnostic.span.end,
+        diagnostic.message,
+    )
+}
+
+fn format_data(data: &Data, indent: usize) -> String {
+    match data {
+        Data::String(value) => json_string(value),
+        Data::Int(value) => value.to_string(),
+        Data::Float(value) => value.to_string(),
+        Data::Bool(value) => value.to_string(),
+        Data::Array(items) => {
+            if items.is_empty() {
+                return String::from("[]");
+            }
+            let mut out = String::from("[\n");
+            for (index, item) in items.iter().enumerate() {
+                out.push_str(&" ".repeat(indent + 2));
+                out.push_str(&format_data(item, indent + 2));
+                if index + 1 != items.len() {
+                    out.push(',');
+                }
+                out.push('\n');
+            }
+            out.push_str(&" ".repeat(indent));
+            out.push(']');
+            out
+        }
+        Data::Object(fields) => {
+            if fields.is_empty() {
+                return String::from("{}");
+            }
+            let mut out = String::from("{\n");
+            for (index, field) in fields.iter().enumerate() {
+                out.push_str(&" ".repeat(indent + 2));
+                out.push_str(&json_string(&field.name));
+                out.push_str(": ");
+                out.push_str(&format_data(&field.value, indent + 2));
+                if index + 1 != fields.len() {
+                    out.push(',');
+                }
+                out.push('\n');
+            }
+            out.push_str(&" ".repeat(indent));
+            out.push('}');
+            out
+        }
+    }
+}
+
+fn json_string(value: &str) -> String {
+    let mut out = String::from("\"");
+    for ch in value.chars() {
+        match ch {
+            '"' => out.push_str("\\\""),
+            '\\' => out.push_str("\\\\"),
+            '\n' => out.push_str("\\n"),
+            '\r' => out.push_str("\\r"),
+            '\t' => out.push_str("\\t"),
+            ch if ch.is_control() => {
+                use core::fmt::Write;
+                let _ = write!(out, "\\u{:04x}", ch as u32);
+            }
+            ch => out.push(ch),
+        }
+    }
+    out.push('"');
+    out
+}