Try to cut down on the # of unicode crates we use

Cargo.lock

@@ -1286,7 +1286,7 @@ dependencies = [
  "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "unic-emoji-char 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unic-ucd-ident 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "wtf8 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1354,7 +1354,6 @@ dependencies = [
  "unic 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "unic-common 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-casing 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode_names2 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "wasm-bindgen 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",

parser/Cargo.toml

@@ -17,6 +17,6 @@ log="0.4.1"
 regex = "1"
 num-bigint = "0.2"
 num-traits = "0.2"
-unicode-xid = "0.2.0"
-unic-emoji-char = "0.9.0"
+unic-emoji-char = "0.9"
+unic-ucd-ident = "0.9"
 wtf8 = "0.0.3"

parser/src/lexer.rs

@@ -2,9 +2,6 @@
 //!
 //! This means source code is translated into separate tokens.
 
-extern crate unic_emoji_char;
-extern crate unicode_xid;
-
 pub use super::token::Tok;
 use crate::error::{LexicalError, LexicalErrorType};
 use crate::location::Location;
@@ -15,8 +12,7 @@ use std::cmp::Ordering;
 use std::collections::HashMap;
 use std::str::FromStr;
 use unic_emoji_char::is_emoji_presentation;
-use unicode_xid::UnicodeXID;
-use wtf8;
+use unic_ucd_ident::{is_xid_continue, is_xid_start};
 
 #[derive(Clone, Copy, PartialEq, Debug, Default)]
 struct IndentationLevel {
@@ -658,17 +654,14 @@ where
     }
 
     fn is_identifier_start(&self, c: char) -> bool {
-        match c {
-            '_' => true,
-            c => UnicodeXID::is_xid_start(c),
-        }
+        c == '_' || is_xid_start(c)
     }
 
     fn is_identifier_continuation(&self) -> bool {
         if let Some(c) = self.chr0 {
             match c {
                 '_' | '0'..='9' => true,
-                c => UnicodeXID::is_xid_continue(c),
+                c => is_xid_continue(c),
             }
         } else {
             false

vm/Cargo.toml

@@ -46,7 +46,6 @@ rustc_version_runtime = "0.1.*"
 statrs = "0.12.0"
 caseless = "0.2.1"
 chrono = { version = "=0.4.9", features = ["wasmbind"] }
-unicode-xid = "0.2.0"
 lazy_static = "^1.0.1"
 lexical = "4"
 itertools = "0.8"
@@ -55,6 +54,8 @@ hexf-parse = "0.1.0"
 indexmap = "1.0.2"
 crc = "^1.0.0"
 unicode_names2 = "0.3"
+# TODO: use unic for this; needed for title case:
+# https://github.com/RustPython/RustPython/pull/832#discussion_r275428939
 unicode-casing = "0.1"
 unic = "0.9"
 unic-common = "0.9"

vm/src/obj/objstr.rs

@@ -1,6 +1,3 @@
-extern crate unicode_categories;
-extern crate unicode_xid;
-
 use std::cell::Cell;
 use std::char;
 use std::fmt;
@@ -10,10 +7,10 @@ use std::str::FromStr;
 use std::string::ToString;
 
 use num_traits::ToPrimitive;
+use unic::ucd::category::GeneralCategory;
+use unic::ucd::ident::{is_xid_continue, is_xid_start};
 use unic::ucd::is_cased;
 use unicode_casing::CharExt;
-use unicode_categories::UnicodeCategories;
-use unicode_xid::UnicodeXID;
 
 use super::objbytes::{PyBytes, PyBytesRef};
 use super::objdict::PyDict;
@@ -366,16 +363,7 @@ impl PyString {
                 formatted.push_str(&format!("\\x{:02x}", c as u32));
             } else if c.is_ascii() {
                 formatted.push(c);
-            } else if c.is_other() || c.is_separator() {
-                // According to python following categories aren't printable:
-                // * Cc (Other, Control)
-                // * Cf (Other, Format)
-                // * Cs (Other, Surrogate)
-                // * Co (Other, Private Use)
-                // * Cn (Other, Not Assigned)
-                // * Zl Separator, Line ('\u2028', LINE SEPARATOR)
-                // * Zp Separator, Paragraph ('\u2029', PARAGRAPH SEPARATOR)
-                // * Zs (Separator, Space) other than ASCII space('\x20').
+            } else if !char_is_printable(c) {
                 let code = c as u32;
                 let escaped = if code < 0xff {
                     format!("\\U{:02x}", code)
@@ -742,10 +730,9 @@ impl PyString {
     ///   * Zs (Separator, Space) other than ASCII space('\x20').
     #[pymethod]
     fn isprintable(&self, _vm: &VirtualMachine) -> bool {
-        self.value.chars().all(|c| match c {
-            '\u{0020}' => true,
-            _ => !(c.is_other_control() | c.is_separator()),
-        })
+        self.value
+            .chars()
+            .all(|c| c == '\u{0020}' || char_is_printable(c))
     }
 
     // cpython's isspace ignores whitespace, including \t and \n, etc, unless the whole string is empty
@@ -1094,13 +1081,9 @@ impl PyString {
     #[pymethod]
     fn isidentifier(&self, _vm: &VirtualMachine) -> bool {
         let mut chars = self.value.chars();
-        let is_identifier_start = match chars.next() {
-            Some('_') => true,
-            Some(c) => UnicodeXID::is_xid_start(c),
-            None => false,
-        };
+        let is_identifier_start = chars.next().map_or(false, |c| c == '_' || is_xid_start(c));
         // a string is not an identifier if it has whitespace or starts with a number
-        is_identifier_start && chars.all(UnicodeXID::is_xid_continue)
+        is_identifier_start && chars.all(is_xid_continue)
     }
 
     // https://docs.python.org/3/library/stdtypes.html#str.translate
@@ -1706,6 +1689,20 @@ fn adjust_indices(
     }
 }
 
+// According to python following categories aren't printable:
+// * Cc (Other, Control)
+// * Cf (Other, Format)
+// * Cs (Other, Surrogate)
+// * Co (Other, Private Use)
+// * Cn (Other, Not Assigned)
+// * Zl Separator, Line ('\u2028', LINE SEPARATOR)
+// * Zp Separator, Paragraph ('\u2029', PARAGRAPH SEPARATOR)
+// * Zs (Separator, Space) other than ASCII space('\x20').
+fn char_is_printable(c: char) -> bool {
+    let cat = GeneralCategory::of(c);
+    !(cat.is_other() || cat.is_separator())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;