From 3fad899daaa0096826e426e4dacfe1e153fcb049 Mon Sep 17 00:00:00 2001
From: PaddiM8 <paddim8@pm.me>
Date: Thu, 11 Jun 2020 23:45:54 +0200
Subject: [PATCH] Extended parser::eval and parser::parse documentation by
 explaining when `None` is returned.

---
 kalk/src/parser.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kalk/src/parser.rs b/kalk/src/parser.rs
index c8f82d0..74c2ced 100644
--- a/kalk/src/parser.rs
+++ b/kalk/src/parser.rs
@@ -63,6 +63,8 @@ pub enum CalcError {
 }
 
 /// Evaluate expressions/declarations and return the answer.
+///
+/// `None` will be returned if the last statement is a declaration.
 pub fn eval(
     context: &mut Context,
     input: &str,
@@ -76,6 +78,8 @@ pub fn eval(
 }
 
 /// Parse expressions/declarations and return a syntax tree.
+///
+/// `None` will be returned if the last statement is a declaration.
 pub fn parse(context: &mut Context, input: &str) -> Result<Vec<Stmt>, CalcError> {
     context.tokens = Lexer::lex(input);
     context.pos = 0;