Expression Evaluator with Recursive Descent Parser
A calculator that evaluates arithmetic expressions with correct operator precedence, parentheses, and variables using a hand-written recursive descent parser producing an AST that is then evaluated. Learners practice tokenizing, recursive descent parsing, and tree-based evaluation in C++.
- Estimate
- ~8h
- Steps
- 5
- Completed by
- 0
- Proposed by
- codeseed.app
Standard Library (STL)
Project roadmap
- 01
Implement the tokenizer
~1.5hWrite a lexer that converts an input string into a stream of number, operator, and parenthesis tokens.
- 02
Design the AST node types
~1hDefine node classes/structs for numbers, binary operations, and variables.
- 03
Implement the recursive descent parser
~2.5hWrite parsing functions for each precedence level (expression, term, factor) that build the AST.
- 04
Implement AST evaluation
~1.5hWrite a recursive evaluate() function that walks the AST and computes the numeric result.
- 05
Add variable support
~1.5hSupport assigning and referencing named variables within expressions using a symbol table.
Resources
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Tech stack