Merge pull request #32 from Lilit0x/functions/translate

TRANSLATE String Function: #13

crates/gitql-ast/src/function.rs

@@ -33,6 +33,7 @@ lazy_static! {
         map.insert("substring", text_substring);
         map.insert("stuff", text_stuff);
         map.insert("right", text_right);
+        map.insert("translate", text_translate);
 
         // Date functions
         map.insert("current_date", date_current_date);
@@ -165,6 +166,13 @@ lazy_static! {
                 result: DataType::Text
              },
         );
+        map.insert(
+            "translate",
+            Prototype {
+                parameters: vec![DataType::Text, DataType::Text, DataType::Text],
+                result: DataType::Text
+             },
+        );
 
         // Date functions
         map.insert(
@@ -347,6 +355,23 @@ fn text_right(inputs: Vec<Value>) -> Value {
     return Value::Text(text[text.len() - number_of_chars..text.len()].to_string());
 }
 
+fn text_translate(inputs: Vec<Value>) -> Value {
+    let mut text = inputs[0].as_text();
+    let characters = inputs[1].as_text();
+    let translations = inputs[2].as_text();
+
+    if translations.len() != characters.len() {
+        return Value::Text("".to_string());
+    }
+
+    let translations = translations.chars().collect::<Vec<_>>();
+    for (idx, letter) in characters.char_indices() {
+        text = text.replace(letter, &char::to_string(&translations[idx]));
+    }
+
+    return Value::Text(text);
+}
+
 // Date functions
 
 fn date_current_date(_inputs: Vec<Value>) -> Value {

crates/gitql-ast/src/lib.rs

@@ -1,9 +1,9 @@
 pub mod aggregation;
+pub mod date_utils;
 pub mod expression;
 pub mod function;
 pub mod object;
 pub mod scope;
 pub mod statement;
 pub mod types;
 pub mod value;
-pub mod date_utils;

docs/function/functions.md

@@ -22,6 +22,7 @@ note that all functions names are case-insensitive.
 | SUBSTRING  | Text, Number, Number | Text | Extracts some characters from a string.                       |
 | STUFF      | Text, Number, Number, Text | Deletes a part of a string and then inserts another part into the string, starting at a specified position. |
 | RIGHT      | Text, Number | Text   | Extracts a number of characters from a string (starting from right).|
+| TRANSLATE  | Text, Text, Text, | Text | Returns the string from the first argument after the characters specified in the second argument are translated into the characters specified in the third argument. |
 ### String functions samples
 
 ```sql
@@ -39,6 +40,7 @@ SELECT REPLACE("ABC ABC ABC", "a", "c") as replacedText
 SELECT name, SUBSTRING(name, 1, 5) AS extract FROM commits
 SELECT STUFF("GQL tutorial!", 13, 1, " is fun!")
 SELECT RIGHT("AmrDeveloper", 3) AS extract
+SELECT TRANSLATE("Amr[Dev]{eloper}", "[]{}", "()()")
 ```
 
 ### Date functions