0.0.9

Author: IbrahimShamma99

CHANGELOG.md

@@ -1,3 +1,7 @@
+## [0.0.9] - 2024-01-27
+
+- Add JSON Scanner
+
 ## [0.0.8] - 2024-01-20
 
 - Add Built in Orderby inside js prototype

__tests__/json/simple.test.ts

@@ -0,0 +1,35 @@
+import { Scanner } from '../../src/json-parser/scanner'
+
+describe('JSON Scanner Tests', () => {
+  it('should scan a simple Empty JSON', () => {
+    const source = `[{}]`
+
+    const scanner = new Scanner(source)
+    scanner.scan()
+
+    expect(scanner.tokens).toHaveLength(5)
+  })
+
+  it('should scan a simple JSON with strings ', () => {
+    const source = `[{ "is_user": true , "age": 20 }]`
+
+    const scanner = new Scanner(source)
+    scanner.scan()
+
+    expect(scanner.tokens).toHaveLength(12)
+  })
+
+  it('should scan a JSON with inner schemas', () => {
+    const source = `[{
+      "user": {
+        "name": "John",
+        "age": 20
+      }
+    }]`
+
+    const scanner = new Scanner(source)
+    scanner.scan()
+
+    expect(scanner.tokens).toHaveLength(16)
+  })
+})

package.json

@@ -1,6 +1,6 @@
 {
   "name": "sql-js-data-mapper",
-  "version": "0.0.8",
+  "version": "0.0.9",
   "description": "A tiny compiler that takes SQL and JS object and runs the sql on the object as if the object became a table in the database, using only js",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
@@ -34,4 +34,4 @@
     "@rollup/plugin-babel": "^6.0.2",
     "tape": "^5.6.3"
   }
-}
+}

src/json-parser/parser.ts

@@ -0,0 +1,176 @@
+import { Token, TokenType } from './types'
+
+export class Scanner {
+  public tokens: Token[] = []
+  private current: number = 0
+  private start: number = 0
+  private line: number = 1
+
+  constructor(private readonly source: string) {
+    this.source = this.source.toLowerCase().trim()
+  }
+
+  scan() {
+    while (!this.isAtEnd) {
+      this.start = this.current
+      this.scanTokens()
+      this.advance()
+    }
+    this.addEOF()
+  }
+
+  scanTokens() {
+    const char = this.peek
+    switch (char) {
+      case ' ':
+      case '\r':
+      case '\t':
+        break
+      case '\n':
+        this.line++
+        break
+      case 't':
+        while (this.isCurrentChar) {
+          this.advance()
+        }
+        if (this.lexeme === 'true') {
+          this.addToken(TokenType.TRUE)
+        } else {
+          throw new Error('Invalid token')
+        }
+        break
+      case 'f':
+        while (this.isCurrentChar) {
+          this.advance()
+        }
+        if (this.lexeme === 'false') {
+          this.addToken(TokenType.FALSE)
+        } else {
+          throw new Error('Invalid token')
+        }
+        break
+      case '[':
+        this.addToken(TokenType.SQUARE_RIGHT_BRACKET, '[')
+        break
+      case ']':
+        this.addToken(TokenType.SQUARE_LEFT_BRACKET, ']')
+        break
+      case '{':
+        this.addToken(TokenType.RIGHT_BRACKET, '{')
+        break
+      case '}':
+        this.addToken(TokenType.LEFT_BRACKET, '}')
+        break
+      case ':':
+        this.addToken(TokenType.COLON, ':')
+        break
+      case ',':
+        this.addToken(TokenType.COMMA, ',')
+        break
+      case '.':
+        this.addToken(TokenType.DOT, '.')
+        break
+      case '"':
+        this.string()
+        break
+      default:
+        if (this.isCurrentNumber) {
+          this.number()
+          break
+        }
+        throw new Error('Not implemented yet')
+    }
+  }
+
+  get peek(): string {
+    return this.source[this.current]
+  }
+
+  get peekNext(): string {
+    return this.source[this.current + 1]
+  }
+
+  get isAtEnd(): boolean {
+    return this.current >= this.source.length
+  }
+
+  get currentToken(): Token {
+    return this.tokens[this.current - 1]
+  }
+
+  get lexeme() {
+    return this.source.substring(this.start, this.current)
+  }
+
+  get isCurrentNumber() {
+    return this.peek >= '0' && this.peek <= '9'
+  }
+
+  get isCurrentChar() {
+    return this.peek >= 'a' && this.peek <= 'z'
+  }
+
+  match(lexeme: string) {
+    if (this.peek === lexeme) {
+      this.advance()
+      return true
+    }
+    return false
+  }
+
+  advance() {
+    this.current++
+  }
+
+  addToken(type: TokenType, initLexeme?: string) {
+    this.tokens.push({
+      lexeme: initLexeme ?? this.lexeme,
+      line: this.line,
+      end: this.current,
+      start: this.start,
+      type: type,
+    })
+  }
+
+  addEOF() {
+    this.tokens.push(
+      new Token({
+        lexeme: '\0',
+        end: this.source.length,
+        start: this.source.length,
+        line: this.line,
+        type: TokenType.EOF,
+      })
+    )
+  }
+
+  string() {
+    this.advance()
+    while (this.peek !== '"') {
+      this.advance()
+    }
+    if (this.peekNext === ':') {
+      this.addToken(
+        TokenType.IDENTIFIER,
+        this.source.substring(this.start + 1, this.current)
+      )
+    } else {
+      this.addToken(
+        TokenType.STRING,
+        this.source.substring(this.start + 1, this.current)
+      )
+    }
+  }
+
+  number() {
+    while (this.isCurrentNumber) {
+      this.advance()
+    }
+    if (this.peek === TokenType.DOT) {
+      while (this.isCurrentNumber) {
+        this.advance()
+      }
+    }
+    this.addToken(TokenType.NUMBER)
+  }
+}

src/json-parser/scanner.ts

@@ -0,0 +1,46 @@
+export enum TokenType {
+  DOT = 'DOT',
+  COMMA = 'COMMA',
+  STRING = 'STRING',
+  NUMBER = 'NUMBER',
+  EOF = 'EOF',
+  LEFT_BRACKET = 'LEFT_BRACKET',
+  RIGHT_BRACKET = 'RIGHT_BRACKET',
+  COLON = 'COLON',
+  BOOLEAN = 'BOOLEAN',
+  SQUARE_LEFT_BRACKET = 'SQUARE_LEFT_BRACKET',
+  SQUARE_RIGHT_BRACKET = 'SQUARE_RIGHT_BRACKET',
+  IDENTIFIER = 'IDENTIFIER',
+
+  FALSE = 'FALSE',
+  TRUE = 'TRUE',
+  NULL = 'NULL',
+}
+
+export class Token {
+  public readonly type: TokenType
+  public readonly lexeme: string
+  public readonly line: number
+  public readonly start: number
+  public readonly end: number
+
+  constructor({
+    type,
+    lexeme,
+    line,
+    start,
+    end,
+  }: {
+    type: TokenType
+    lexeme: string
+    line: number
+    start: number
+    end: number
+  }) {
+    this.type = type
+    this.lexeme = lexeme
+    this.line = line
+    this.start = start
+    this.end = end
+  }
+}

src/json-parser/types/index.ts

@@ -107,4 +107,7 @@ export enum TokenType {
   SIMILAR = 'SIMILAR',
 
   INTEGER = 'INTEGER',
+
+  SQUARE_LEFT_BRACKET = 'SQUARE_LEFT_BRACKET',
+  SQUARE_RIGHT_BRACKET = 'SQUARE_RIGHT_BRACKET',
 }