Add tip slot function

crates/tx3-cardano/src/lib.rs

@@ -42,18 +42,26 @@ pub struct Config {
 pub type TxBody =
     pallas::codec::utils::KeepRaw<'static, primitives::conway::TransactionBody<'static>>;
 
+#[derive(Debug, Clone)]
+pub struct ChainPoint {
+    pub slot: u64,
+    pub hash: Vec<u8>,
+}
+
 pub struct Compiler {
     pub pparams: PParams,
     pub config: Config,
     pub latest_tx_body: Option<TxBody>,
+    pub cursor: ChainPoint,
 }
 
 impl Compiler {
-    pub fn new(pparams: PParams, config: Config) -> Self {
+    pub fn new(pparams: PParams, config: Config, cursor: ChainPoint) -> Self {
         Self {
             pparams,
             config,
             latest_tx_body: None,
+            cursor,
         }
     }
 }
@@ -100,6 +108,7 @@ impl tx3_lang::backend::Compiler for Compiler {
                     amount: ir::Expression::Number(lovelace),
                 }]))
             }
+            ir::CompilerOp::ComputeTipSlot => Ok(ir::Expression::Number(self.cursor.slot as i128)),
         }
     }
 }

crates/tx3-cardano/src/tests.rs

@@ -48,7 +48,14 @@ fn test_compiler(config: Option<Config>) -> Compiler {
 
     let config = config.unwrap_or(Config { extra_fees: None });
 
-    Compiler::new(pparams, config)
+    Compiler::new(
+        pparams,
+        config,
+        ChainPoint {
+            slot: 101674141,
+            hash: vec![],
+        },
+    )
 }
 
 fn load_protocol(example_name: &str) -> Protocol {

crates/tx3-lang/src/applying.rs

@@ -1150,6 +1150,7 @@ impl Composite for ir::CompilerOp {
         match self {
             ir::CompilerOp::BuildScriptAddress(x) => vec![x],
             ir::CompilerOp::ComputeMinUtxo(x) => vec![x],
+            ir::CompilerOp::ComputeTipSlot => vec![],
         }
     }
 
@@ -1160,6 +1161,7 @@ impl Composite for ir::CompilerOp {
         match self {
             ir::CompilerOp::BuildScriptAddress(x) => Ok(ir::CompilerOp::BuildScriptAddress(f(x)?)),
             ir::CompilerOp::ComputeMinUtxo(x) => Ok(ir::CompilerOp::ComputeMinUtxo(f(x)?)),
+            ir::CompilerOp::ComputeTipSlot => Ok(ir::CompilerOp::ComputeTipSlot),
         }
     }
 }

crates/tx3-lang/src/ast.rs

@@ -699,6 +699,7 @@ pub enum DataExpr {
     AnyAssetConstructor(AnyAssetConstructor),
     Identifier(Identifier),
     MinUtxo(Identifier),
+    ComputeTipSlot,
     AddOp(AddOp),
     SubOp(SubOp),
     ConcatOp(ConcatOp),
@@ -738,6 +739,7 @@ impl DataExpr {
             DataExpr::AnyAssetConstructor(x) => x.target_type(),
             DataExpr::UtxoRef(_) => Some(Type::UtxoRef),
             DataExpr::MinUtxo(_) => Some(Type::AnyAsset),
+            DataExpr::ComputeTipSlot => Some(Type::Int),
         }
     }
 }

crates/tx3-lang/src/ir.rs

@@ -70,6 +70,7 @@ pub enum BuiltInOp {
 pub enum CompilerOp {
     BuildScriptAddress(Expression),
     ComputeMinUtxo(Expression),
+    ComputeTipSlot,
 }
 
 #[derive(Encode, Decode, Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
@@ -465,6 +466,7 @@ impl Node for CompilerOp {
         let visited = match self {
             CompilerOp::BuildScriptAddress(x) => CompilerOp::BuildScriptAddress(x.apply(visitor)?),
             CompilerOp::ComputeMinUtxo(x) => CompilerOp::ComputeMinUtxo(x.apply(visitor)?),
+            CompilerOp::ComputeTipSlot => CompilerOp::ComputeTipSlot,
         };
 
         Ok(visited)

crates/tx3-lang/src/lowering.rs

@@ -449,6 +449,9 @@ impl IntoLower for ast::DataExpr {
             ast::DataExpr::MinUtxo(x) => ir::Expression::EvalCompiler(Box::new(
                 ir::CompilerOp::ComputeMinUtxo(x.into_lower(ctx)?),
             )),
+            ast::DataExpr::ComputeTipSlot => {
+                ir::Expression::EvalCompiler(Box::new(ir::CompilerOp::ComputeTipSlot))
+            }
         };
 
         Ok(out)

crates/tx3-lang/src/parsing.rs

@@ -1094,6 +1094,10 @@ impl DataExpr {
         Ok(DataExpr::MinUtxo(Identifier::parse(inner)?))
     }
 
+    fn tip_slot_parse(_pair: Pair<Rule>) -> Result<Self, Error> {
+        Ok(DataExpr::ComputeTipSlot)
+    }
+
     fn concat_constructor_parse(pair: Pair<Rule>) -> Result<Self, Error> {
         Ok(DataExpr::ConcatOp(ConcatOp::parse(pair)?))
     }
@@ -1180,6 +1184,7 @@ impl AstNode for DataExpr {
                 Rule::any_asset_constructor => DataExpr::any_asset_constructor_parse(x),
                 Rule::concat_constructor => DataExpr::concat_constructor_parse(x),
                 Rule::min_utxo => DataExpr::min_utxo_parse(x),
+                Rule::tip_slot => DataExpr::tip_slot_parse(x),
                 Rule::data_expr => DataExpr::parse(x),
                 x => unreachable!("unexpected rule as data primary: {:?}", x),
             })
@@ -1220,6 +1225,7 @@ impl AstNode for DataExpr {
             DataExpr::PropertyOp(x) => &x.span,
             DataExpr::UtxoRef(x) => x.span(),
             DataExpr::MinUtxo(x) => x.span(),
+            DataExpr::ComputeTipSlot => &Span::DUMMY, // TODO
         }
     }
 }
@@ -1986,6 +1992,24 @@ mod tests {
         })
     );
 
+    input_to_ast_check!(
+        DataExpr,
+        "tip_slot_basic",
+        "tip_slot()",
+        DataExpr::ComputeTipSlot
+    );
+
+    input_to_ast_check!(
+        DataExpr,
+        "tip_slot_in_expression",
+        "1000 + tip_slot()",
+        DataExpr::AddOp(AddOp {
+            lhs: Box::new(DataExpr::Number(1000)),
+            rhs: Box::new(DataExpr::ComputeTipSlot),
+            span: Span::DUMMY,
+        })
+    );
+
     input_to_ast_check!(
         StructConstructor,
         "struct_constructor_record",

crates/tx3-lang/src/tx3.pest

@@ -126,6 +126,8 @@ concat_constructor = {
 
 min_utxo = { "min_utxo" ~ "(" ~ identifier ~ ")" }
 
+tip_slot = { "tip_slot" ~ "(" ~ ")" }
+
 data_expr = { data_prefix* ~ data_primary ~ data_postfix* ~ (data_infix ~ data_prefix* ~ data_primary ~ data_postfix* )* }
 
     data_infix = _{ data_add | data_sub }
@@ -147,6 +149,7 @@ data_expr = { data_prefix* ~ data_primary ~ data_postfix* ~ (data_infix ~ data_p
         bool |
         string |
         min_utxo |
+        tip_slot |
         struct_constructor |
         list_constructor |
         concat_constructor |

examples/tip_slot.tx3

@@ -0,0 +1,22 @@
+party Sender;
+
+type TimestampDatum {
+    current_slot: Int,
+    expiry_slot: Int,
+}
+
+tx create_timestamp_tx(validity_period: Int) {
+    input source {
+        from: Sender,
+        min_amount: Ada(2000000),
+    }
+
+    output timestamp_output {
+        to: Sender,
+        amount: source - fees,
+        datum: TimestampDatum {
+            current_slot: tip_slot(),
+            expiry_slot: tip_slot() + validity_period,
+        },
+    }
+}