Modularized into separate files

Add ToString implementation on the components

src/sqlast/value.rs

@@ -0,0 +1,62 @@
+
+use chrono::{NaiveDate,
+             NaiveDateTime,
+             NaiveTime,
+             offset::{FixedOffset,
+                 TimeZone,
+             },
+             DateTime,
+             Utc,
+            };
+
+use uuid::Uuid;
+
+/// SQL values such as int, double, string timestamp
+#[derive(Debug, Clone, PartialEq)]
+pub enum Value{
+    /// Literal signed long
+    Long(i64),
+    /// Literal floating point value
+    Double(f64),
+    /// Unquoted string
+    String(String),
+    /// Uuid value
+    Uuid(Uuid),
+    /// 'string value'
+    SingleQuotedString(String),
+    /// "string value"
+    DoubleQuotedString(String),
+    /// Boolean value true or false,
+    Boolean(bool),
+    /// Date value
+    Date(NaiveDate),
+    // Time
+    Time(NaiveTime),
+    /// Date and time
+    DateTime(NaiveDateTime),
+    /// Timstamp with time zone
+    Timestamp(DateTime<FixedOffset>),
+    /// NULL value in insert statements,
+    Null,
+}
+
+
+impl ToString for Value{
+    
+    fn to_string(&self) -> String {
+        match self{
+            Value::Long(v) => v.to_string(),
+            Value::Double(v) => v.to_string(),
+            Value::String(v) => v.to_string(),
+            Value::Uuid(v) => v.to_string(),
+            Value::SingleQuotedString(v) => format!("'{}'", v),
+            Value::DoubleQuotedString(v) => format!("\"{}\"", v),
+            Value::Boolean(v) => v.to_string(),
+            Value::Date(v) => v.to_string(),
+            Value::Time(v) => v.to_string(),
+            Value::DateTime(v) => v.to_string(),
+            Value::Timestamp(v) => format!("{}", v),
+            Value::Null => "NULL".to_string(),
+        }
+    }
+}