Change Value::Long() to u64, use u64 instead of usize

The tokenizer emits a separate Token for +/- signs, so the value of
Value::Long() (as well as of parse_literal_int()) may never be negative.

Also we have been using both u64 and usize to represent a parsed
unsigned number. Change to using u64 for consistency.

src/sqlast/sqltype.rs

@@ -1,26 +1,26 @@
 use super::SQLObjectName;
 
-/// SQL datatypes for literals in SQL statements
+/// SQL data types
 #[derive(Debug, Clone, PartialEq)]
 pub enum SQLType {
     /// Fixed-length character type e.g. CHAR(10)
-    Char(Option<usize>),
+    Char(Option<u64>),
     /// Variable-length character type e.g. VARCHAR(10)
-    Varchar(Option<usize>),
+    Varchar(Option<u64>),
     /// Uuid type
     Uuid,
     /// Large character object e.g. CLOB(1000)
-    Clob(usize),
+    Clob(u64),
     /// Fixed-length binary type e.g. BINARY(10)
-    Binary(usize),
+    Binary(u64),
     /// Variable-length binary type e.g. VARBINARY(10)
-    Varbinary(usize),
+    Varbinary(u64),
     /// Large binary object e.g. BLOB(1000)
-    Blob(usize),
+    Blob(u64),
     /// Decimal type with optional precision and scale e.g. DECIMAL(10,2)
-    Decimal(Option<usize>, Option<usize>),
+    Decimal(Option<u64>, Option<u64>),
     /// Floating point with optional precision e.g. FLOAT(8)
-    Float(Option<usize>),
+    Float(Option<u64>),
     /// Small integer
     SmallInt,
     /// Integer
@@ -87,7 +87,7 @@ impl ToString for SQLType {
     }
 }
 
-fn format_type_with_optional_length(sql_type: &str, len: &Option<usize>) -> String {
+fn format_type_with_optional_length(sql_type: &str, len: &Option<u64>) -> String {
     let mut s = sql_type.to_string();
     if let Some(len) = len {
         s += &format!("({})", len);

src/sqlast/value.rs

@@ -1,15 +1,15 @@
-/// SQL values such as int, double, string, timestamp
+/// Primitive SQL values such as number and string
 #[derive(Debug, Clone, PartialEq)]
 pub enum Value {
-    /// Literal signed long
-    Long(i64),
-    /// Literal floating point value
+    /// Unsigned integer value
+    Long(u64),
+    /// Unsigned floating point value
     Double(f64),
     /// 'string value'
     SingleQuotedString(String),
     /// N'string value'
     NationalStringLiteral(String),
-    /// Boolean value true or false,
+    /// Boolean value true or false
     Boolean(bool),
     /// NULL value in insert statements,
     Null,

src/sqlparser.rs

@@ -351,14 +351,8 @@ impl Parser {
             let rows = if self.parse_keyword("UNBOUNDED") {
                 None
             } else {
-                let rows = self.parse_literal_int()?;
-                if rows < 0 {
-                    parser_err!(format!(
-                        "The number of rows must be non-negative, got {}",
-                        rows
-                    ))?;
-                }
-                Some(rows as u64)
+                let rows = self.parse_literal_uint()?;
+                Some(rows)
             };
             if self.parse_keyword("PRECEDING") {
                 Ok(SQLWindowFrameBound::Preceding(rows))
@@ -1059,9 +1053,9 @@ impl Parser {
                     Ok(n) => Ok(Value::Double(n)),
                     Err(e) => parser_err!(format!("Could not parse '{}' as f64: {}", n, e)),
                 },
-                Token::Number(ref n) => match n.parse::<i64>() {
+                Token::Number(ref n) => match n.parse::<u64>() {
                     Ok(n) => Ok(Value::Long(n)),
-                    Err(e) => parser_err!(format!("Could not parse '{}' as i64: {}", n, e)),
+                    Err(e) => parser_err!(format!("Could not parse '{}' as u64: {}", n, e)),
                 },
                 Token::SingleQuotedString(ref s) => Ok(Value::SingleQuotedString(s.to_string())),
                 Token::NationalStringLiteral(ref s) => {
@@ -1073,13 +1067,13 @@ impl Parser {
         }
     }
 
-    /// Parse a literal integer/long
-    pub fn parse_literal_int(&mut self) -> Result<i64, ParserError> {
+    /// Parse an unsigned literal integer/long
+    pub fn parse_literal_uint(&mut self) -> Result<u64, ParserError> {
         match self.next_token() {
-            Some(Token::Number(s)) => s.parse::<i64>().map_err(|e| {
-                ParserError::ParserError(format!("Could not parse '{}' as i64: {}", s, e))
+            Some(Token::Number(s)) => s.parse::<u64>().map_err(|e| {
+                ParserError::ParserError(format!("Could not parse '{}' as u64: {}", s, e))
             }),
-            other => parser_err!(format!("Expected literal int, found {:?}", other)),
+            other => self.expected("literal int", other),
         }
     }
 
@@ -1258,17 +1252,11 @@ impl Parser {
         }
     }
 
-    pub fn parse_precision(&mut self) -> Result<usize, ParserError> {
-        //TODO: error handling
-        Ok(self.parse_optional_precision()?.unwrap())
-    }
-
-    pub fn parse_optional_precision(&mut self) -> Result<Option<usize>, ParserError> {
+    pub fn parse_optional_precision(&mut self) -> Result<Option<u64>, ParserError> {
         if self.consume_token(&Token::LParen) {
-            let n = self.parse_literal_int()?;
-            //TODO: check return value of reading rparen
+            let n = self.parse_literal_uint()?;
             self.expect_token(&Token::RParen)?;
-            Ok(Some(n as usize))
+            Ok(Some(n))
         } else {
             Ok(None)
         }
@@ -1276,16 +1264,16 @@ impl Parser {
 
     pub fn parse_optional_precision_scale(
         &mut self,
-    ) -> Result<(Option<usize>, Option<usize>), ParserError> {
+    ) -> Result<(Option<u64>, Option<u64>), ParserError> {
         if self.consume_token(&Token::LParen) {
-            let n = self.parse_literal_int()?;
+            let n = self.parse_literal_uint()?;
             let scale = if self.consume_token(&Token::Comma) {
-                Some(self.parse_literal_int()? as usize)
+                Some(self.parse_literal_uint()?)
             } else {
                 None
             };
             self.expect_token(&Token::RParen)?;
-            Ok((Some(n as usize), scale))
+            Ok((Some(n), scale))
         } else {
             Ok((None, None))
         }
@@ -1725,7 +1713,7 @@ impl Parser {
         if self.parse_keyword("ALL") {
             Ok(None)
         } else {
-            self.parse_literal_int()
+            self.parse_literal_uint()
                 .map(|n| Some(ASTNode::SQLValue(Value::Long(n))))
         }
     }
@@ -1733,7 +1721,7 @@ impl Parser {
     /// Parse an OFFSET clause
     pub fn parse_offset(&mut self) -> Result<ASTNode, ParserError> {
         let value = self
-            .parse_literal_int()
+            .parse_literal_uint()
             .map(|n| ASTNode::SQLValue(Value::Long(n)))?;
         self.expect_one_of_keywords(&["ROW", "ROWS"])?;
         Ok(value)

src/sqltokenizer.rs

@@ -29,7 +29,7 @@ use super::dialect::Dialect;
 pub enum Token {
     /// A keyword (like SELECT) or an optionally quoted SQL identifier
     SQLWord(SQLWord),
-    /// Numeric literal
+    /// An unsigned numeric literal
     Number(String),
     /// A character that could not be tokenized
     Char(char),