Refactor AST to improve types

src/AST.type.ts

@@ -0,0 +1,102 @@
+import { JSONValue } from './JSON.type';
+
+export interface FieldNode {
+  readonly type: 'Field';
+  readonly name: string;
+}
+
+export interface LiteralNode {
+  readonly type: 'Literal';
+  readonly value: JSONValue;
+}
+
+export interface IndexNode {
+  readonly type: 'Index';
+  readonly value: number;
+}
+
+export interface FilterProjectionNode {
+  readonly type: 'FilterProjection';
+  readonly left: ExpressionNode;
+  readonly right: ExpressionNode;
+  readonly condition: ExpressionNode;
+}
+
+export interface SliceNode {
+  readonly type: 'Slice';
+  readonly start: number | null;
+  readonly stop: number | null;
+  readonly step: number | null;
+}
+
+export type ComparatorType = 'GT' | 'LT' | 'GTE' | 'LTE' | 'NE' | 'EQ';
+
+export interface ComparatorNode {
+  readonly type: 'Comparator';
+  readonly name: ComparatorType;
+  readonly left: ExpressionNode;
+  readonly right: ExpressionNode;
+}
+
+export interface KeyValuePairNode {
+  readonly type: 'KeyValuePair';
+  readonly name: string;
+  readonly value: ExpressionNode;
+}
+
+export interface MultiSelectHashNode {
+  type: 'MultiSelectHash';
+  children: KeyValuePairNode[];
+}
+
+export interface MultiSelectListNode {
+  type: 'MultiSelectList';
+  children: ExpressionNode[];
+}
+
+export interface FunctionNode {
+  readonly type: 'Function';
+  readonly name: string;
+  readonly children: ExpressionNode[];
+}
+
+type BinaryExpressionType =
+  | 'Subexpression'
+  | 'Pipe'
+  | 'ValueProjection'
+  | 'IndexExpression'
+  | 'Projection'
+  | 'OrExpression'
+  | 'AndExpression';
+
+type UnaryExpressionType = 'NotExpression' | 'Flatten' | 'ExpressionReference';
+type SimpleExpressionType = 'Identity' | 'Current' | 'Root';
+
+export interface SimpleExpressionNode<T extends SimpleExpressionType = SimpleExpressionType> {
+  readonly type: T;
+}
+export interface UnaryExpressionNode<T extends UnaryExpressionType = UnaryExpressionType> {
+  readonly type: T;
+  readonly child: ExpressionNode;
+}
+export interface BinaryExpressionNode<T extends BinaryExpressionType = BinaryExpressionType> {
+  readonly type: T;
+  readonly left: ExpressionNode;
+  readonly right: ExpressionNode;
+}
+
+export type ExpressionNode =
+  | SimpleExpressionNode
+  | UnaryExpressionNode
+  | BinaryExpressionNode
+  | ComparatorNode
+  | SliceNode
+  | FilterProjectionNode
+  | IndexNode
+  | LiteralNode
+  | FieldNode
+  | MultiSelectHashNode
+  | MultiSelectListNode
+  | FunctionNode;
+
+export type ExpressionReference = { expref: true } & ExpressionNode;

src/JSON.type.ts

@@ -0,0 +1,6 @@
+export type ObjectDict<T = unknown> = Record<string, T | undefined>;
+
+export type JSONPrimitive = string | number | boolean | null;
+export type JSONValue = JSONPrimitive | JSONObject | JSONArray;
+export type JSONObject = { [member: string]: JSONValue };
+export type JSONArray = JSONValue[];

src/Lexer.ts

@@ -1,71 +1,6 @@
+import { JSONValue } from './JSON.type';
+import { LexerToken, Token } from './Lexer.type';
 import { isAlpha, isNum, isAlphaNum } from './utils/index';
-import type { JSONValue } from './index';
-
-export enum Token {
-  TOK_EOF = 'EOF',
-  TOK_UNQUOTEDIDENTIFIER = 'UnquotedIdentifier',
-  TOK_QUOTEDIDENTIFIER = 'QuotedIdentifier',
-  TOK_RBRACKET = 'Rbracket',
-  TOK_RPAREN = 'Rparen',
-  TOK_COMMA = 'Comma',
-  TOK_COLON = 'Colon',
-  TOK_RBRACE = 'Rbrace',
-  TOK_NUMBER = 'Number',
-  TOK_CURRENT = 'Current',
-  TOK_ROOT = 'Root',
-  TOK_EXPREF = 'Expref',
-  TOK_PIPE = 'Pipe',
-  TOK_OR = 'Or',
-  TOK_AND = 'And',
-  TOK_EQ = 'EQ',
-  TOK_GT = 'GT',
-  TOK_LT = 'LT',
-  TOK_GTE = 'GTE',
-  TOK_LTE = 'LTE',
-  TOK_NE = 'NE',
-  TOK_FLATTEN = 'Flatten',
-  TOK_STAR = 'Star',
-  TOK_FILTER = 'Filter',
-  TOK_DOT = 'Dot',
-  TOK_NOT = 'Not',
-  TOK_LBRACE = 'Lbrace',
-  TOK_LBRACKET = 'Lbracket',
-  TOK_LPAREN = 'Lparen',
-  TOK_LITERAL = 'Literal',
-}
-
-export type LexerTokenValue = JSONValue;
-
-export interface LexerToken {
-  type: Token;
-  value: LexerTokenValue;
-  start: number;
-}
-
-export interface ASTNode {
-  type: string;
-}
-
-export interface ValueNode<T = LexerTokenValue> extends ASTNode {
-  value: T;
-}
-
-export interface FieldNode extends ASTNode {
-  name: LexerTokenValue;
-}
-
-export type KeyValuePairNode = FieldNode & ValueNode<ExpressionNodeTree>;
-
-export interface ExpressionNode<T = ExpressionNodeTree> extends ASTNode {
-  children: T[];
-  jmespathType?: Token;
-}
-
-export interface ComparitorNode extends ExpressionNode {
-  name: Token;
-}
-
-export type ExpressionNodeTree = ASTNode | ExpressionNode | FieldNode | ValueNode;
 
 export const basicTokens: Record<string, Token> = {
   '(': Token.TOK_LPAREN,
@@ -323,7 +258,7 @@ class StreamLexer {
       try {
         JSON.parse(literalString);
         return true;
-      } catch (ex) {
+      } catch {
         return false;
       }
     }

src/Lexer.type.ts

@@ -0,0 +1,42 @@
+import { JSONValue } from './JSON.type';
+
+export enum Token {
+  TOK_EOF = 'EOF',
+  TOK_UNQUOTEDIDENTIFIER = 'UnquotedIdentifier',
+  TOK_QUOTEDIDENTIFIER = 'QuotedIdentifier',
+  TOK_RBRACKET = 'Rbracket',
+  TOK_RPAREN = 'Rparen',
+  TOK_COMMA = 'Comma',
+  TOK_COLON = 'Colon',
+  TOK_RBRACE = 'Rbrace',
+  TOK_NUMBER = 'Number',
+  TOK_CURRENT = 'Current',
+  TOK_ROOT = 'Root',
+  TOK_EXPREF = 'Expref',
+  TOK_PIPE = 'Pipe',
+  TOK_OR = 'Or',
+  TOK_AND = 'And',
+  TOK_EQ = 'EQ',
+  TOK_GT = 'GT',
+  TOK_LT = 'LT',
+  TOK_GTE = 'GTE',
+  TOK_LTE = 'LTE',
+  TOK_NE = 'NE',
+  TOK_FLATTEN = 'Flatten',
+  TOK_STAR = 'Star',
+  TOK_FILTER = 'Filter',
+  TOK_DOT = 'Dot',
+  TOK_NOT = 'Not',
+  TOK_LBRACE = 'Lbrace',
+  TOK_LBRACKET = 'Lbracket',
+  TOK_LPAREN = 'Lparen',
+  TOK_LITERAL = 'Literal',
+}
+
+export type LexerTokenValue = JSONValue;
+
+export interface LexerToken {
+  type: Token;
+  value: LexerTokenValue;
+  start: number;
+}