fix exponential number parsing (#7)

Author: Dean Karn

CHANGELOG.md

@@ -6,6 +6,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.3.1] - 2022-07-19
+### Fixed
+- Fixed number parsing for exponential numbers eg. 1e10.
+
 ## [0.3.0] - 2022-07-19
 ### Added
 - Added BETWEEN operator support <value> BETWEEN <value> <value>
@@ -31,8 +35,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 - Initial conversion from https://github.com/rust-playground/ksql.
 
-[Unreleased]: https://github.com/go-playground/ksql/compare/v0.3.0...HEAD
-[0.2.0]: https://github.com/go-playground/ksql/compare/v0.2.0...v0.3.0
+[Unreleased]: https://github.com/go-playground/ksql/compare/v0.3.1...HEAD
+[0.3.1]: https://github.com/go-playground/ksql/compare/v0.3.0...v0.3.1
+[0.3.0]: https://github.com/go-playground/ksql/compare/v0.2.0...v0.3.0
 [0.2.0]: https://github.com/go-playground/ksql/compare/v0.1.1...v0.2.0
 [0.1.1]: https://github.com/go-playground/ksql/compare/v0.1.0...v0.1.1
 [0.1.0]: https://github.com/go-playground/ksql/commit/v0.1.0

README.md

@@ -1,6 +1,6 @@
 ksql
 =====
-![Project status](https://img.shields.io/badge/version-0.3.0-green.svg)
+![Project status](https://img.shields.io/badge/version-0.3.1-green.svg)
 [![GoDoc](https://godoc.org/github.com/go-playground/ksql?status.svg)](https://pkg.go.dev/github.com/go-playground/ksql)
 ![License](https://img.shields.io/dub/l/vibe-d.svg)
 
@@ -69,7 +69,7 @@ Expressions support most mathematical and string expressions see below for detai
 | `CloseBracket` | `]`                      | N/A                                                                                                                                                                                       |
 | `Comma`        | `,`                      | N/A                                                                                                                                                                                       |
 | `QuotedString` | `"sample text"`          | Must start and end with an unescaped `"` character                                                                                                                                        |
-| `Number`       | `123.45`                 | Must start and end with a valid `0-9` digit.                                                                                                                                              |
+| `Number`       | ` 123.45 `               | Must start and end with a space or '+' or '-' when hard coded value in expression and supports `0-9 +- e` characters for numbers and exponent notation.                                   |
 | `BooleanTrue`  | `true`                   | Accepts `true` as a boolean only.                                                                                                                                                         |
 | `BooleanFalse` | `false`                  | Accepts `false` as a boolean only.                                                                                                                                                        |
 | `SelectorPath` | `.selector_path`         | Starts with a `.` and ends with whitespace blank space. This crate currently uses [gjson](https://github.com/tidwall/gjson.rs) and so the full gjson syntax for identifiers is supported. |

lexer.go

@@ -67,9 +67,17 @@ func tokenizeSingleToken(data []byte) (result LexerResult, err error) {
 			result = LexerResult{kind: Equals, len: 1}
 		}
 	case '+':
-		result = LexerResult{kind: Add, len: 1}
+		if len(data) > 1 && isDigit(data[1]) {
+			result, err = tokenizeNumber(data)
+		} else {
+			result = LexerResult{kind: Add, len: 1}
+		}
 	case '-':
-		result = LexerResult{kind: Subtract, len: 1}
+		if len(data) > 1 && isDigit(data[1]) {
+			result, err = tokenizeNumber(data)
+		} else {
+			result = LexerResult{kind: Subtract, len: 1}
+		}
 	case '*':
 		result = LexerResult{kind: Multiply, len: 1}
 	case '/':

lexer_test.go

@@ -337,6 +337,31 @@ func Test(t *testing.T) {
 			input:  "BETWEEN ",
 			tokens: []Token{{kind: Between, start: 0, len: 7}},
 		},
+		{
+			name:   "parse negative number",
+			input:  " -1.23 ",
+			tokens: []Token{{kind: Number, start: 1, len: 5}},
+		},
+		{
+			name:   "parse positive number",
+			input:  " +1.23 ",
+			tokens: []Token{{kind: Number, start: 1, len: 5}},
+		},
+		{
+			name:   "parse positive number",
+			input:  " +1.23 ",
+			tokens: []Token{{kind: Number, start: 1, len: 5}},
+		},
+		{
+			name:   "parse negative exponential number",
+			input:  " -1e10 ",
+			tokens: []Token{{kind: Number, start: 1, len: 5}},
+		},
+		{
+			name:   "parse positive exponential number",
+			input:  " +1e10 ",
+			tokens: []Token{{kind: Number, start: 1, len: 5}},
+		},
 	}
 
 	for _, tc := range tests {

parser_test.go

@@ -500,6 +500,24 @@ func TestParser(t *testing.T) {
 			src:      ``,
 			expected: false,
 		},
+		{
+			name:     "parse exponent number eq",
+			exp:      `1e3 == 1000`,
+			src:      ``,
+			expected: true,
+		},
+		{
+			name:     "parse negative exponent number eq",
+			exp:      `-1e-3 == -0.001`,
+			src:      ``,
+			expected: true,
+		},
+		{
+			name:     "parse positive exponent number eq",
+			exp:      `+1e-3 == 0.001`,
+			src:      ``,
+			expected: true,
+		},
 	}
 
 	for _, tc := range tests {