Package com.helix.core.parser

Class ExpressionRuleParser

java.lang.Object

com.helix.core.parser.ExpressionRuleParser

public class ExpressionRuleParser
extends Object

High-performance, lightweight recursive-descent parser for human-readable rule expressions. Compiles expressions directly into Helix AST nodes with microsecond latency (<20 µs).

Grammar precedence (lowest to highest):

1. Logical OR: ||
2. Logical AND: &&
3. Equality: ==, !=
4. Relational / Comparison: <, <=, >, >=
5. Additive: +, -
6. Multiplicative: *, /, %
7. Unary prefix: !, -, +
8. Postfix: field access .field, method call .method(args)
9. Primary: literals, function calls fn(args), variables, grouped (expr)

Constructor Summary

Constructors

Constructor	Description
ExpressionRuleParser()

Method Summary

Modifier and Type	Method	Description
ExpressionNode	parse(String expression)	Parses a raw expression string into an AST ExpressionNode.
ExpressionNode	parseAndFold(String expression)	Parses and optimizes an expression using constant folding and dead code elimination.
ExpressionNode	parseAndValidate(String expression, Map<String,Class<?>> schema)	Parses an expression, optimizes it, and validates types against the given schema.
RuleNode	parseRule(String name, String expression)
RuleNode	parseRule(String name, String version, String description, String category, String expression, Map<String,Class<?>> schema)	Parses a named rule with the specified metadata and schema, applying folding and type checking.
RuleNode	parseRule(String name, String expression, Map<String,Class<?>> schema)	Parses a named rule with the specified schema, applying folding and type checking.
void	validate(String expression)	Validates expression syntax.
void	validate(String expression, Map<String,Class<?>> schema)	Validates expression syntax and type compatibility against a schema.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ExpressionRuleParser

public ExpressionRuleParser()

Method Details

parse

public ExpressionNode parse(String expression)
                     throws ExpressionParseException

Parses a raw expression string into an AST ExpressionNode.

Parameters:

expression - expression text

Returns:

parsed AST root node

Throws:

ExpressionParseException - if expression has syntax errors

parseAndFold

public ExpressionNode parseAndFold(String expression)
                            throws ExpressionParseException

Parses and optimizes an expression using constant folding and dead code elimination.

Parameters:

expression - expression text

Returns:

optimized AST root node

Throws:

ExpressionParseException - if expression has syntax errors

parseAndValidate

public ExpressionNode parseAndValidate(String expression,
 Map<String,Class<?>> schema)
                                throws ExpressionParseException,
TypeMismatchException

Parses an expression, optimizes it, and validates types against the given schema.

Parameters:

expression - expression text

schema - variable schema

Returns:

optimized and type-checked AST ExpressionNode

Throws:

ExpressionParseException - if syntax is invalid

TypeMismatchException - if type validation fails

parseRule

public RuleNode parseRule(String name,
 String version,
 String description,
 String category,
 String expression,
 Map<String,Class<?>> schema)
                   throws ExpressionParseException,
TypeMismatchException

Parses a named rule with the specified metadata and schema, applying folding and type checking.

Parameters:

name - rule name

version - rule version

description - rule description

category - rule category

expression - expression text

schema - variable schema

Returns:

compiled RuleNode

Throws:

ExpressionParseException

TypeMismatchException

parseRule

public RuleNode parseRule(String name,
 String expression,
 Map<String,Class<?>> schema)
                   throws ExpressionParseException,
TypeMismatchException

Parses a named rule with the specified schema, applying folding and type checking.

Throws:

ExpressionParseException

TypeMismatchException

parseRule

public RuleNode parseRule(String name,
 String expression)
                   throws ExpressionParseException

Throws:

ExpressionParseException

validate

public void validate(String expression,
 Map<String,Class<?>> schema)
              throws ExpressionParseException,
TypeMismatchException

Validates expression syntax and type compatibility against a schema.

Throws:

ExpressionParseException

TypeMismatchException

validate

public void validate(String expression)
              throws ExpressionParseException

Validates expression syntax.

Throws:

ExpressionParseException