diff --git a/src/common.rs b/src/common.rs
index 807e31a..361d3d8 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -476,7 +476,7 @@ impl Display for Pos {
 }
 
 #[derive(Debug, Clone, Default)]
-pub struct Scope {
+pub(crate) struct Scope {
     pub vars: HashMap<String, Vec<Token>>,
     pub mixins: HashMap<String, Mixin>,
 }
diff --git a/src/css.rs b/src/css.rs
index 4ba4e33..d520a1f 100644
--- a/src/css.rs
+++ b/src/css.rs
@@ -4,14 +4,14 @@ use std::fmt;
 use std::io::Write;
 
 #[derive(Debug, Clone)]
-pub enum Toplevel {
+enum Toplevel {
     RuleSet(Selector, Vec<BlockEntry>),
     MultilineComment(String),
     // AtRule(AtRule),
 }
 
 #[derive(Debug, Clone)]
-pub enum BlockEntry {
+enum BlockEntry {
     Style(Style),
     MultilineComment(String),
     // AtRule(AtRule),
diff --git a/src/function.rs b/src/function.rs
index 13b8e24..8885f06 100644
--- a/src/function.rs
+++ b/src/function.rs
@@ -6,10 +6,10 @@ use crate::utils::devour_whitespace;
 use crate::{Token, TokenKind};
 
 #[derive(Debug, Clone, Eq, PartialEq)]
-pub struct FuncArgs(pub Vec<FuncArg>);
+pub(crate) struct FuncArgs(pub Vec<FuncArg>);
 
 #[derive(Debug, Clone, Eq, PartialEq)]
-pub struct FuncArg {
+pub(crate) struct FuncArg {
     pub name: String,
     pub default: Option<Vec<Token>>,
 }
@@ -21,7 +21,7 @@ impl FuncArgs {
 }
 
 #[derive(Debug, Clone, std::default::Default)]
-pub struct CallArgs(pub BTreeMap<String, Vec<Token>>);
+pub(crate) struct CallArgs(pub BTreeMap<String, Vec<Token>>);
 
 impl CallArgs {
     pub fn new() -> Self {
@@ -37,7 +37,7 @@ impl CallArgs {
     }
 }
 
-pub fn eat_func_args<I: Iterator<Item = Token>>(toks: &mut Peekable<I>) -> FuncArgs {
+pub(crate) fn eat_func_args<I: Iterator<Item = Token>>(toks: &mut Peekable<I>) -> FuncArgs {
     let mut args: Vec<FuncArg> = Vec::new();
 
     devour_whitespace(toks);
@@ -112,7 +112,7 @@ pub fn eat_func_args<I: Iterator<Item = Token>>(toks: &mut Peekable<I>) -> FuncA
     FuncArgs(args)
 }
 
-pub fn eat_call_args<I: Iterator<Item = Token>>(toks: &mut Peekable<I>) -> CallArgs {
+pub(crate) fn eat_call_args<I: Iterator<Item = Token>>(toks: &mut Peekable<I>) -> CallArgs {
     let mut args: BTreeMap<String, Vec<Token>> = BTreeMap::new();
     devour_whitespace(toks);
     let mut name: Option<String> = None;
diff --git a/src/imports.rs b/src/imports.rs
index 64a95dd..0f2c13c 100644
--- a/src/imports.rs
+++ b/src/imports.rs
@@ -3,7 +3,7 @@ use crate::{SassResult, Stmt, StyleSheet};
 use std::ffi::OsStr;
 use std::path::Path;
 
-pub fn import<P: AsRef<Path>>(path: P) -> SassResult<(Vec<Stmt>, Scope)> {
+pub(crate) fn import<P: AsRef<Path>>(path: P) -> SassResult<(Vec<Stmt>, Scope)> {
     let mut rules: Vec<Stmt> = Vec::new();
     let mut scope = Scope::new();
     let path_buf = path.as_ref().to_path_buf();
diff --git a/src/lexer.rs b/src/lexer.rs
index 7daf2f1..ac1f5fa 100644
--- a/src/lexer.rs
+++ b/src/lexer.rs
@@ -8,7 +8,7 @@ use crate::units::Unit;
 use crate::{Token, TokenKind, Whitespace};
 
 #[derive(Debug, Clone)]
-pub struct Lexer<'a> {
+pub(crate) struct Lexer<'a> {
     tokens: Vec<Token>,
     buf: Peekable<Chars<'a>>,
     pos: Pos,
diff --git a/src/lib.rs b/src/lib.rs
index 9b24c52..8d59885 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -76,7 +76,7 @@ mod utils;
 pub type SassResult<T> = Result<T, SassError>;
 
 #[derive(Clone, Debug, Eq, PartialEq)]
-pub struct Token {
+pub(crate) struct Token {
     pos: Pos,
     pub kind: TokenKind,
 }
@@ -100,10 +100,9 @@ impl IsWhitespace for &Token {
 }
 
 #[derive(Clone, Debug, Eq, PartialEq)]
-pub enum TokenKind {
+pub(crate) enum TokenKind {
     Ident(String),
     Symbol(Symbol),
-    String(String),
     AtRule(AtRuleKind),
     Keyword(Keyword),
     Number(String),
@@ -122,7 +121,6 @@ impl Display for TokenKind {
         match self {
             TokenKind::Ident(s) | TokenKind::Number(s) => write!(f, "{}", s),
             TokenKind::Symbol(s) => write!(f, "{}", s),
-            TokenKind::String(s) => write!(f, "\"{}\"", s),
             TokenKind::AtRule(s) => write!(f, "{}", s),
             TokenKind::Op(s) => write!(f, "{}", s),
             TokenKind::Unit(s) => write!(f, "{}", s),
@@ -143,7 +141,7 @@ impl Display for TokenKind {
 pub struct StyleSheet(Vec<Stmt>);
 
 #[derive(Clone, Debug, Eq, PartialEq)]
-pub enum Stmt {
+pub(crate) enum Stmt {
     /// A [`Style`](/grass/style/struct.Style)
     Style(Style),
     /// A  [`RuleSet`](/grass/struct.RuleSet.html)
@@ -163,7 +161,7 @@ pub enum Stmt {
 /// }
 /// ```
 #[derive(Clone, Debug, Eq, PartialEq)]
-pub struct RuleSet {
+pub(crate) struct RuleSet {
     selector: Selector,
     rules: Vec<Stmt>,
     // potential optimization: we don't *need* to own the selector
@@ -245,16 +243,32 @@ impl StyleSheet {
     ///
     /// Used mainly in debugging, but can at times be useful
     #[inline]
-    pub fn pretty_print<W: Write>(&self, buf: W) -> SassResult<()> {
+    #[allow(dead_code)]
+    fn pretty_print<W: Write>(&self, buf: W) -> SassResult<()> {
         PrettyPrinter::new(buf).pretty_print(self)
     }
 
+    #[inline]
     #[allow(dead_code)]
     fn pretty_print_selectors<W: Write>(&self, buf: W) -> SassResult<()> {
         PrettyPrinter::new(buf).pretty_print_preserve_super_selectors(self)
     }
 
     /// Write the internal representation as CSS to `buf`
+    /// 
+    /// ```
+    /// use std::io::{BufWriter, stdout};
+    /// use grass::{SassResult, StyleSheet};
+    /// # use tempfile::Builder;
+    /// # use std::io::Write;
+    /// 
+    /// fn main() -> SassResult<()> {
+    ///     # let mut file = Builder::new().prefix("input.scss").tempfile().unwrap();
+    ///     # write!(file, "a {{\n  color: red}}")?;
+    ///     let mut buf = BufWriter::new(stdout());
+    ///     StyleSheet::from_path("input.scss")?.print_as_css(&mut buf)
+    /// }
+    /// ```
     #[inline]
     pub fn print_as_css<W: Write>(self, buf: &mut W) -> SassResult<()> {
         Css::from_stylesheet(self).pretty_print(buf)
@@ -1190,7 +1204,6 @@ mod test_mixins {
 mod test_imports {
     use super::*;
     use tempfile::Builder;
-    use Write;
 
     macro_rules! test_import {
         ($func:ident, $input:literal => $output:literal | $( $name:literal($content:literal) ),*) => {
diff --git a/src/mixin.rs b/src/mixin.rs
index 55dc1d0..3e72e7b 100644
--- a/src/mixin.rs
+++ b/src/mixin.rs
@@ -8,7 +8,7 @@ use crate::utils::devour_whitespace;
 use crate::{eat_expr, Expr, RuleSet, Stmt, Token, TokenKind};
 
 #[derive(Debug, Clone)]
-pub struct Mixin {
+pub(crate) struct Mixin {
     scope: Scope,
     args: FuncArgs,
     body: Peekable<IntoIter<Token>>,
@@ -92,7 +92,7 @@ impl Mixin {
         self.eval(super_selector)
     }
 
-    pub fn eval(&mut self, super_selector: &Selector) -> Result<Vec<Stmt>, (Pos, String)> {
+    fn eval(&mut self, super_selector: &Selector) -> Result<Vec<Stmt>, (Pos, String)> {
         let mut stmts = Vec::new();
         while let Some(expr) = eat_expr(&mut self.body, &self.scope, super_selector)? {
             match expr {
@@ -118,7 +118,7 @@ impl Mixin {
     }
 }
 
-pub fn eat_include<I: Iterator<Item = Token>>(
+pub(crate) fn eat_include<I: Iterator<Item = Token>>(
     toks: &mut Peekable<I>,
     scope: &Scope,
     super_selector: &Selector,
diff --git a/src/selector.rs b/src/selector.rs
index 812f2be..3665a18 100644
--- a/src/selector.rs
+++ b/src/selector.rs
@@ -7,7 +7,7 @@ use std::string::ToString;
 use std::vec::IntoIter;
 
 #[derive(Clone, Debug, Eq, PartialEq)]
-pub struct Selector(pub Vec<SelectorKind>);
+pub(crate) struct Selector(pub Vec<SelectorKind>);
 
 impl Display for Selector {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -47,7 +47,7 @@ impl Display for Selector {
 }
 
 #[derive(Clone, Debug, Eq, PartialEq)]
-pub enum SelectorKind {
+pub(crate) enum SelectorKind {
     /// An element selector: `button`
     Element(String),
     /// An id selector: `#footer`
diff --git a/src/style.rs b/src/style.rs
index 43d9c11..34971f0 100644
--- a/src/style.rs
+++ b/src/style.rs
@@ -7,7 +7,7 @@ use std::vec::IntoIter;
 
 /// A style: `color: red`
 #[derive(Clone, Debug, Eq, PartialEq)]
-pub struct Style {
+pub(crate) struct Style {
     property: String,
     value: String,
 }
diff --git a/src/units.rs b/src/units.rs
index e675769..9025e93 100644
--- a/src/units.rs
+++ b/src/units.rs
@@ -2,7 +2,7 @@ use std::convert::TryFrom;
 use std::fmt;
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
-pub enum Unit {
+pub(crate) enum Unit {
     // Absolute units
     /// Pixels
     Px,
diff --git a/src/utils.rs b/src/utils.rs
index 24e91ac..6c68c4d 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -2,11 +2,11 @@ use crate::common::{Pos, Symbol, Whitespace};
 use crate::{Scope, Token, TokenKind};
 use std::iter::{Iterator, Peekable};
 
-pub trait IsWhitespace {
+pub(crate) trait IsWhitespace {
     fn is_whitespace(&self) -> bool;
 }
 
-pub fn devour_whitespace<I: Iterator<Item = W>, W: IsWhitespace>(s: &mut Peekable<I>) -> bool {
+pub(crate) fn devour_whitespace<I: Iterator<Item = W>, W: IsWhitespace>(s: &mut Peekable<I>) -> bool {
     let mut found_whitespace = false;
     while let Some(w) = s.peek() {
         if !w.is_whitespace() {
@@ -19,7 +19,7 @@ pub fn devour_whitespace<I: Iterator<Item = W>, W: IsWhitespace>(s: &mut Peekabl
 }
 
 #[track_caller]
-pub fn deref_variable(name: &str, scope: &Scope) -> Vec<Token> {
+pub(crate) fn deref_variable(name: &str, scope: &Scope) -> Vec<Token> {
     let mut toks = scope
         .vars
         .get(name)
@@ -45,7 +45,7 @@ pub fn deref_variable(name: &str, scope: &Scope) -> Vec<Token> {
     val
 }
 
-pub fn eat_interpolation<I: Iterator<Item = Token>>(
+pub(crate) fn eat_interpolation<I: Iterator<Item = Token>>(
     tokens: &mut Peekable<I>,
     scope: &Scope,
 ) -> Vec<Token> {
@@ -63,7 +63,7 @@ pub fn eat_interpolation<I: Iterator<Item = Token>>(
     val
 }
 
-pub fn eat_variable_value<I: Iterator<Item = Token>>(
+pub(crate) fn eat_variable_value<I: Iterator<Item = Token>>(
     toks: &mut Peekable<I>,
     scope: &Scope,
 ) -> Result<Vec<Token>, (Pos, String)> {