UPDATE: Adds bindings to update timezone and locale

UPDATE: Update "generate locale" utility

FIX: Minor fixes to UI and proper support for locales/timezones

UPDATE: Adds "display language" setting to core

base/src/expressions/parser/tests/test_languages.rs

@@ -0,0 +1,56 @@
+use std::collections::HashMap;
+
+use crate::expressions::parser::{DefinedNameS, Node, Parser};
+use crate::expressions::types::CellReferenceRC;
+
+use crate::expressions::parser::stringify::to_localized_string;
+use crate::functions::Function;
+use crate::language::get_language;
+use crate::locale::get_locale;
+use crate::types::Table;
+
+pub fn to_string(t: &Node, cell_reference: &CellReferenceRC) -> String {
+    let locale = get_locale("en").unwrap();
+    let language = get_language("es").unwrap();
+    to_localized_string(t, cell_reference, locale, language)
+}
+
+pub fn new_parser(
+    worksheets: Vec<String>,
+    defined_names: Vec<DefinedNameS>,
+    tables: HashMap<String, Table>,
+) -> Parser {
+    let locale = get_locale("en").unwrap();
+    let language = get_language("es").unwrap();
+    Parser::new(worksheets, defined_names, tables, locale, language)
+}
+
+#[test]
+fn simple_language() {
+    let worksheets = vec!["Sheet1".to_string(), "Second Sheet".to_string()];
+    let mut parser = new_parser(worksheets, vec![], HashMap::new());
+    // Reference cell is Sheet1!A1
+    let cell_reference = CellReferenceRC {
+        sheet: "Sheet1".to_string(),
+        row: 1,
+        column: 1,
+    };
+    let t = parser.parse("FALSO", &cell_reference);
+    assert!(matches!(t, Node::BooleanKind(false)));
+
+    let t = parser.parse("VERDADERO", &cell_reference);
+    assert!(matches!(t, Node::BooleanKind(true)));
+
+    let t = parser.parse("TRUE()", &cell_reference);
+    assert!(matches!(t, Node::InvalidFunctionKind { ref name, args: _} if name == "TRUE"));
+
+    let t = parser.parse("VERDADERO()", &cell_reference);
+    assert!(matches!(
+        t,
+        Node::FunctionKind {
+            kind: Function::True,
+            args: _
+        }
+    ));
+    assert_eq!(to_string(&t, &cell_reference), "VERDADERO()".to_string());
+}