constraints basic imports

simple.program

@@ -1,9 +1,4 @@
-from "./path/to/my/module" import MySymbol
-
-def foo() -> (field):
-    // return myGlobal <- not allowed
-    return 42
+from "./simple_import" import foo
 
 def main() -> (field):
-    myGlobal = 42
     return foo()

simple_import.program

@@ -0,0 +1,3 @@
+def foo() -> (field):
+    // return myGlobal <- not allowed
+    return 42

src/aleo_program/constraints.rs

@@ -1,9 +1,11 @@
 use crate::aleo_program::{
     Assignee, BooleanExpression, BooleanSpreadOrExpression, Expression, FieldExpression,
-    FieldRangeOrExpression, FieldSpreadOrExpression, Function, Program, Statement, Struct,
+    FieldRangeOrExpression, FieldSpreadOrExpression, Function, Import, Program, Statement, Struct,
     StructMember, Type, Variable,
 };
+use crate::ast;
 
+use from_pest::FromPest;
 use snarkos_models::curves::{Field, PrimeField};
 use snarkos_models::gadgets::utilities::eq::EqGadget;
 use snarkos_models::gadgets::{
@@ -12,6 +14,7 @@ use snarkos_models::gadgets::{
 };
 use std::collections::HashMap;
 use std::fmt;
+use std::fs;
 
 #[derive(Clone)]
 pub enum ResolvedValue {
@@ -756,6 +759,8 @@ impl ResolvedProgram {
             Assignee::Variable(name) => {
                 // Store the variable in the current scope
                 let definition_name = new_scope_from_variable(scope.clone(), &name);
+
+                // Evaluate the rhs expression in the current function scope
                 let result = self.enforce_expression(cs, scope, expression);
 
                 self.store(definition_name, result);
@@ -958,25 +963,33 @@ impl ResolvedProgram {
                 // Check that argument is correct type
                 match parameter.ty.clone() {
                     Type::FieldElement => {
-                        match self.enforce_expression(cs, function.name(), argument) {
+                        match self.enforce_expression(cs, function.get_name(), argument) {
                             ResolvedValue::FieldElement(field) => {
                                 // Store argument as variable with {function_name}_{parameter name}
-                                let variable_name =
-                                    new_scope_from_variable(function.name(), &parameter.variable);
+                                let variable_name = new_scope_from_variable(
+                                    function.get_name(),
+                                    &parameter.variable,
+                                );
                                 self.store(variable_name, ResolvedValue::FieldElement(field));
                             }
                             argument => unimplemented!("expected field argument got {}", argument),
                         }
                     }
-                    Type::Boolean => match self.enforce_expression(cs, function.name(), argument) {
+                    Type::Boolean => {
+                        match self.enforce_expression(cs, function.get_name(), argument) {
                             ResolvedValue::Boolean(bool) => {
                                 // Store argument as variable with {function_name}_{parameter name}
-                            let variable_name =
-                                new_scope_from_variable(function.name(), &parameter.variable);
+                                let variable_name = new_scope_from_variable(
+                                    function.get_name(),
+                                    &parameter.variable,
+                                );
                                 self.store(variable_name, ResolvedValue::Boolean(bool));
                             }
-                        argument => unimplemented!("expected boolean argument got {}", argument),
-                    },
+                            argument => {
+                                unimplemented!("expected boolean argument got {}", argument)
+                            }
+                        }
+                    }
                     ty => unimplemented!("parameter type {} not matched yet", ty),
                 }
             });
@@ -991,38 +1004,88 @@ impl ResolvedProgram {
             .into_iter()
             .for_each(|statement| match statement {
                 Statement::Definition(variable, expression) => {
-                    self.enforce_definition_statement(cs, function.name(), variable, expression);
+                    self.enforce_definition_statement(
+                        cs,
+                        function.get_name(),
+                        variable,
+                        expression,
+                    );
                 }
                 Statement::For(index, start, stop, statements) => {
-                    self.enforce_for_statement(cs, function.name(), index, start, stop, statements);
+                    self.enforce_for_statement(
+                        cs,
+                        function.get_name(),
+                        index,
+                        start,
+                        stop,
+                        statements,
+                    );
                 }
                 Statement::Return(expressions) => {
-                    return_values = self.enforce_return_statement(cs, function.name(), expressions)
+                    return_values =
+                        self.enforce_return_statement(cs, function.get_name(), expressions)
                 }
             });
 
         return_values
     }
 
+    fn enforce_import<F: Field + PrimeField, CS: ConstraintSystem<F>>(
+        &mut self,
+        cs: &mut CS,
+        import: Import,
+    ) {
+        // println!("import: {}", import);
+
+        // Resolve program file path
+        let unparsed_file = fs::read_to_string(import.get_file()).expect("cannot read file");
+        let mut file = ast::parse(&unparsed_file).expect("unsuccessful parse");
+        // println!("successful import parse!");
+
+        // generate ast from file
+        let syntax_tree = ast::File::from_pest(&mut file).expect("infallible");
+
+        // generate aleo program from file
+        let program = Program::from(syntax_tree);
+        // println!(" compiled: {:#?}", program);
+
+        // recursively evaluate program statements TODO: in file scope
+        self.resolve_definitions(cs, program);
+
+        // store import under designated name
+        // self.store(name, value)
+    }
+
+    pub fn resolve_definitions<F: Field + PrimeField, CS: ConstraintSystem<F>>(
+        &mut self,
+        cs: &mut CS,
+        program: Program,
+    ) {
+        program
+            .imports
+            .into_iter()
+            .for_each(|import| self.enforce_import(cs, import));
+        program
+            .structs
+            .into_iter()
+            .for_each(|(variable, struct_def)| {
+                self.store_variable(variable, ResolvedValue::StructDefinition(struct_def));
+            });
+        program
+            .functions
+            .into_iter()
+            .for_each(|(function_name, function)| {
+                self.store(function_name.0, ResolvedValue::Function(function));
+            });
+    }
+
     pub fn generate_constraints<F: Field + PrimeField, CS: ConstraintSystem<F>>(
         cs: &mut CS,
         program: Program,
     ) {
         let mut resolved_program = ResolvedProgram::new();
 
-        program
-            .structs
-            .into_iter()
-            .for_each(|(variable, struct_def)| {
-                resolved_program
-                    .store_variable(variable, ResolvedValue::StructDefinition(struct_def));
-            });
-        program
-            .functions
-            .into_iter()
-            .for_each(|(function_name, function)| {
-                resolved_program.store(function_name.0, ResolvedValue::Function(function));
-            });
+        resolved_program.resolve_definitions(cs, program);
 
         let main = resolved_program
             .get(&"main".into())

src/aleo_program/imports.rs

@@ -44,6 +44,11 @@ impl<'ast> Import<'ast> {
     pub fn get_source(&self) -> &Path {
         &self.source
     }
+
+    pub fn get_file(&self) -> String {
+        let path = self.get_source().to_str().unwrap();
+        format!("{}.program", path)
+    }
 }
 
 impl<'ast> fmt::Display for Import<'ast> {
@@ -64,7 +69,7 @@ impl<'ast> fmt::Debug for Import<'ast> {
                 self.source.display(),
                 alias
             ),
-            None => write!(f, "import source: {})", self.source.display()),
+            None => write!(f, "import( source: {})", self.source.display()),
         }
     }
 }

src/aleo_program/types.rs

@@ -167,7 +167,7 @@ pub struct Function {
 }
 
 impl Function {
-    pub fn name(&self) -> String {
+    pub fn get_name(&self) -> String {
         self.function_name.0.clone()
     }
 }
@@ -175,11 +175,19 @@ impl Function {
 /// A simple program with statement expressions, program arguments and program returns.
 #[derive(Debug, Clone)]
 pub struct Program<'ast> {
+    pub name: Variable,
     pub imports: Vec<Import<'ast>>,
     pub structs: HashMap<Variable, Struct>,
     pub functions: HashMap<FunctionName, Function>,
 }
 
+impl<'ast> Program<'ast> {
+    pub fn name(mut self, name: String) -> Self {
+        self.name = Variable(name);
+        self
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/aleo_program/types_from.rs

@@ -1,5 +1,4 @@
 //! Logic to convert from an abstract syntax tree (ast) representation to a typed zokrates_program.
-//! We implement "unwrap" functions instead of the From trait to handle nested statements (flattening).
 //!
 //! @file zokrates_program.rs
 //! @author Collin Chin <collin@aleo.org>
@@ -793,6 +792,7 @@ impl<'ast> From<ast::File<'ast>> for types::Program<'ast> {
         });
 
         types::Program {
+            name: types::Variable("".into()),
             imports,
             structs,
             functions,

src/main.rs

@@ -50,6 +50,7 @@ impl<F: Field + PrimeField> ConstraintSynthesizer<F> for Benchmark<F> {
         let program = aleo_program::Program::from(syntax_tree);
         println!(" compiled: {:#?}", program);
 
+        let program = program.name("simple".into());
         aleo_program::ResolvedProgram::generate_constraints(cs, program);
 
         Ok(())