1 files changed, 42 insertions, 24 deletions

diff --git a/src/pattern.rs b/src/pattern.rs
index fc3c8a7..0fc6acd 100644
--- a/src/pattern.rs
+++ b/src/pattern.rs
@@ -7,7 +7,7 @@ use std::borrow::Borrow;
 use std::collections::BTreeMap;
 
 use serde::de::Deserialize;
-use serde::de::DeserializeSeed;
+use serde::de::DeserializeSeed as _;
 use serde::de::Deserializer;
 use serde::ser::Serialize;
 
@@ -26,7 +26,7 @@ use crate::vm::MAX_CALLS;
 /// use datafu::Pattern;
 ///
 /// let pattern = Pattern::<()>::compile::<&str, &str>(
-///     "->'hello'",
+///     "->['value']'hello'",
 ///     None, None
 /// ).expect("failed to compile pattern");
 /// ```
@@ -35,7 +35,28 @@ pub struct Pattern<O: Serialize> {
 }
 
 impl<O: Serialize> Pattern<O> {
-    /// Compiles the input into a pattern.
+    /// Matches the pattern against an input.
+    pub fn deserialize<'de, Der, De>(&self, der: Der) -> Result<De, Der::Error>
+    where
+        Der: Deserializer<'de>,
+        De: Deserialize<'de>,
+    {
+        let mut err = Default::default();
+        let interp = vm::Interpreter::new(&self.consts, &mut err);
+        let pack = vm::Packer::new(interp, MAX_CALLS).deserialize(der)?;
+        let de = De::deserialize(vm::Unpacker::new(pack.0, MAX_CALLS));
+        todo!()
+    }
+}
+
+pub struct PatternBuilder<'s, PKey=&'static str, OKey=&'static str, O=()> {
+    input: &'s str,
+    preds: Option<BTreeMap<PKey, Box<Predicate>>>,
+    objs: Option<BTreeMap<OKey, O>>,
+}
+
+impl<'s> PatternBuilder<'s> {
+    /// Creates a PatternBuilder for a given pattern.
     ///
     /// # Examples
     ///
@@ -69,28 +90,25 @@ impl<O: Serialize> Pattern<O> {
     ///     Some(preds), None
     /// ).expect("failed to compile pattern");
     /// ```
-    pub fn compile<'s, PKey, OKey>(
-        input: &'s str,
-        preds: Option<BTreeMap<PKey, Box<Predicate>>>,
-        objs: Option<BTreeMap<OKey, O>>
-    ) -> Result<Self, PatternError<'s>>
-    where
-        PKey: Borrow<str> + Ord,
-        OKey: Borrow<str> + Ord,
-    {
-        Ok(Self {
-            consts: parse(input, preds, objs)?
-        })
+    pub fn for_pattern(pattern: &'s str) -> Self {
+        Self {
+            input: pattern,
+            preds: None,
+            objs: None,
+        }
     }
+}
 
-    /// Matches the pattern against an input.
-    pub fn deserialize<'de, Der, De>(&self, der: Der) -> Result<De, Der::Error>
-    where
-        Der: Deserializer<'de>,
-        De: Deserialize<'de>,
-    {
-        let pack = vm::Packer::new(&self.consts, MAX_CALLS).deserialize(der)?;
-        let de = De::deserialize(vm::Unpacker::new(pack, MAX_CALLS));
-        todo!()
+impl<'s, PKey, OKey, O> PatternBuilder<'s, PKey, OKey, O>
+where
+    PKey: Borrow<str> + Ord,
+    OKey: Borrow<str> + Ord,
+    O: Serialize,
+{
+    /// Compiles the pattern.
+    pub fn compile(self) -> Result<Pattern<O>, PatternError<'s>> {
+        Ok(Pattern {
+            consts: parse(self.input, self.preds, self.objs)?
+        })
     }
 }