diff options
Diffstat (limited to 'src/runtime.rs')
| -rw-r--r-- | src/runtime.rs | 86 |
1 files changed, 62 insertions, 24 deletions
diff --git a/src/runtime.rs b/src/runtime.rs index 9612659..789d31a 100644 --- a/src/runtime.rs +++ b/src/runtime.rs @@ -111,16 +111,10 @@ pub fn reduce_term( ) -> ReductionResult { let term = &*term_rc; - match term { - Term::Primitive(_) => Ok((term_rc, 0)), - Term::Variable(_) => substitute_var(term_rc, bound_variable_opt), + let (result_term, result_n) = match term { + Term::Primitive(_) => Ok((Rc::clone(&term_rc), 0)), + Term::Variable(_) => substitute_var(Rc::clone(&term_rc), bound_variable_opt), Term::Application(lhs_rc, rhs_rc) => { - let (subst_lhs_rc, lhs_n) = reduce_term( - symbol_table, - Rc::clone(lhs_rc), - bound_variable_opt, - resolve_lazy, - )?; let (subst_rhs_rc, rhs_n) = reduce_term( symbol_table, Rc::clone(rhs_rc), @@ -128,23 +122,55 @@ pub fn reduce_term( resolve_lazy, )?; - let subst_n = lhs_n + rhs_n; + let (result, app_n) = match &**lhs_rc { + Term::Abstraction(abs_v, abs_body_rc) => { + let (reduced_term, reduced_n) = reduce_term( + symbol_table, + Rc::clone(abs_body_rc), + &Some((*abs_v, subst_rhs_rc)), + resolve_lazy, + )?; - let (result, app_n) = match &*subst_lhs_rc { - Term::Abstraction(abs_v, abs_body_rc) => reduce_term( - symbol_table, - Rc::clone(abs_body_rc), - &Some((*abs_v, subst_rhs_rc)), - resolve_lazy, - ), - Term::Builtin(builtin) => builtins::evaluate_builtin(builtin, subst_rhs_rc), - _ => Ok(( - Rc::new(Term::Application(subst_lhs_rc, subst_rhs_rc)), - subst_n, - )), + let result: ReductionResult = Ok((reduced_term, reduced_n + 1)); + result + } + Term::Builtin(builtin) => { + let (builtin_evaled_terms, builtin_n) = + builtins::evaluate_builtin(builtin, subst_rhs_rc)?; + + // TODO: think this through + if builtin_n > 0 { + if cfg!(feature = "reduce_debug") { + println!(":: builtin_n: {} > 0", builtin_n); + println!( + ":: returning builtin_evaled_terms:\n{}\n", + builtin_evaled_terms + ); + } + Ok((builtin_evaled_terms, rhs_n + builtin_n)) + } else { + if cfg!(feature = "reduce_debug") { + println!(":: builtin_n: {} < 0", builtin_n); + println!(":: returning application as is:\n{}\n", term); + } + Ok((Rc::clone(&term_rc), rhs_n)) + } + } + _ => { + let (subst_lhs_rc, lhs_n) = reduce_term( + symbol_table, + Rc::clone(lhs_rc), + bound_variable_opt, + resolve_lazy, + )?; + Ok(( + Rc::new(Term::Application(subst_lhs_rc, subst_rhs_rc)), + rhs_n + lhs_n, + )) + } }?; - Ok((result, app_n + subst_n)) + Ok((result, app_n)) } Term::Abstraction(abs_v, body_rc) => { let (subst_body, subst_n) = reduce_term( @@ -155,7 +181,7 @@ pub fn reduce_term( )?; Ok((Rc::new(Term::Abstraction(*abs_v, subst_body)), subst_n)) } - Term::Builtin(_) => Ok((term_rc, 0)), + Term::Builtin(_) => Ok((Rc::clone(&term_rc), 0)), // Term::Lazy(symbol) => { // if resolve_lazy { // let table_lookup_value = symbol_table.get(symbol); @@ -186,7 +212,19 @@ pub fn reduce_term( // } // } _ => todo!("reduce_term cases"), + }?; + + if cfg!(feature = "reduce_debug") { + println!( + "reduce_term with:\nterm_rc:\n{}\nbound_variable_opt:\n{}\nresolve_lazy:\n{}\n", + Rc::clone(&term_rc), + _bound_variable_opt_to_string(bound_variable_opt), + resolve_lazy + ); + println!("result_term:\n{}\nresult_n: {}\n", result_term, result_n); + println!("\n=========\n"); } + Ok((result_term, result_n)) } const MAX_REDUCTION_ITERATIONS: usize = 1000; |