Remove lexy dependency, replace with hand-written tokenizer and Pratt parser

[facontidavide]

Summary

• Remove vendored lexy library (~28k lines) and replace the lexy-based script grammar with a hand-written tokenizer + Pratt parser
• Add src/script_tokenizer.cpp implementing BT::Scripting::tokenize() for all token types (identifiers with @ prefix, numbers, strings, operators)
• Conditionally use std::from_chars for double/float when available (__cpp_lib_to_chars_fp_formatting)

Test plan

• All 334 existing tests pass (verified locally)
• Script parser tests cover: arithmetic, comparisons, assignments, string concat, ternary, bitwise ops, hex literals, exponents, chained comparisons, error cases
• Blackboard tests with @-prefixed root variables pass

🤖 Generated with Claude Code

Summary by CodeRabbit

• Removed Features
  • Removed embedded parser combinator library and related build configuration files.

[coderabbitai]

Important

Review skipped

Review was skipped as selected files did not have any reviewable changes.

💤 Files selected but had no reviewable changes (3)

• src/script_parser.cpp
• src/script_tokenizer.cpp
• tests/script_parser_test.cpp

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• 🔍 Trigger a full review

📝 Walkthrough

Walkthrough

The pull request removes the entire 3rdparty/lexy directory and related build configuration. This includes the lexy parser library's source code, build files, documentation, and all associated headers, along with two additions to .gitignore.

Changes

Cohort / File(s)	Summary
Build & Configuration .gitignore, 3rdparty/lexy/CMakeLists.txt, 3rdparty/lexy/cmake/lexyConfig.cmake.in	Deletion of CMake build configuration, license file, README documentation, and package configuration template. Addition of /.worktrees/ and TODO.md to .gitignore.
Core Library Infrastructure 3rdparty/lexy/include/lexy/_detail/{any_ref, assert, buffer_builder, code_point, config, detect, integer_sequence, invoke, iterator, lazy_init, memory_resource, nttp_string, stateless_lambda, std, string_view, swar, tuple, type_name, unicode_database}.hpp	Removal of fundamental internal utility headers providing type-erasing references, assertion macros, buffer management, code point handling, configuration flags, type detection, sequence utilities, invocation mechanics, iterator adapters, lazy initialization, memory resources, compile-time strings, standard library shims, and Unicode database.
Action & Validation System 3rdparty/lexy/include/lexy/action/{base, match, parse, parse_as_tree, scan, trace, validate}.hpp	Deletion of complete action execution framework including parsing, matching, validation, tracing, and tree construction logic.
Callback Framework 3rdparty/lexy/include/lexy/callback.hpp, 3rdparty/lexy/include/lexy/callback/{adapter, aggregate, base, bind, bit_cast, composition, constant, container, fold, forward, integer, noop, object, string}.hpp	Removal of callback aggregator header and all specialized callback implementations for adapters, aggregates, binding, composition, containers, folding, object construction, and string handling.
Core Public Types 3rdparty/lexy/include/lexy/{code_point, dsl}.hpp	Deletion of code point type system and primary DSL aggregation header.
DSL Base & Fundamental Rules 3rdparty/lexy/include/lexy/dsl/{any, base}.hpp	Removal of wildcard token matcher and foundational parser event structures and utilities.
DSL Character & Literal Matching 3rdparty/lexy/include/lexy/dsl/{ascii, bits, bom, brackets, byte, char_class, code_point, literal}.hpp	Deletion of character class DSL, ASCII utilities, bit-level parsing, BOM detection, bracket matching, byte-level parsing, and literal matching infrastructure.
DSL Control Flow & Branching 3rdparty/lexy/include/lexy/dsl/{branch, choice, error, expression, if, loop}.hpp	Removal of branch composition, choice operators, error handling, expression parsing (with operator precedence), conditional rules, and loop/while constructs.
DSL Context & State Management 3rdparty/lexy/include/lexy/dsl/{context_counter, context_flag, context_identifier}.hpp	Deletion of parse-context variable management for counters, flags, and identifier tracking.
DSL Delimited & Structured Content 3rdparty/lexy/include/lexy/dsl/{capture, case_folding, delimited, follow}.hpp	Removal of content capture, case folding, delimiter matching, and lookahead utilities.
DSL Numeric & Operator Parsing 3rdparty/lexy/include/lexy/dsl/{digit, integer, operator, sign}.hpp	Deletion of digit/radix parsing, integer parsing with bounds checking, operator literal parsing, and sign handling.
DSL Parsing Utilities & Modifiers 3rdparty/lexy/include/lexy/dsl/{effect, eof, identifier, member, newline, option, peek, position}.hpp	Removal of side effects, EOF detection, identifier/keyword parsing, member assignment, newline matching, optional values, lookahead/peek, and position tracking.
DSL Production & Sequence Composition 3rdparty/lexy/include/lexy/dsl/{production, sequence, subgrammar}.hpp	Deletion of production rules, sequence composition via operator overloads, and subgrammar integration.
DSL List & Repetition 3rdparty/lexy/include/lexy/dsl/{combination, list, repeat, separator, times}.hpp	Removal of list parsing, combination/permutation matching, repetition with separators, and N-times operators.
DSL Symbol Table & Termination 3rdparty/lexy/include/lexy/dsl/{parse_as, parse_tree_node, punctuator, recover, return, scan, symbol, terminator}.hpp	Deletion of symbol table matching, parse-tree nodes, punctuation literals, error recovery, early return, input scanning, and terminator handling.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

The diff involves large-scale deletion of an entire third-party library (lexy) spanning hundreds of files and thousands of lines. While the changes are homogeneous in nature (consistent pattern of complete file removal), the sheer scope requires careful verification that all lexy references are cleanly removed from the rest of the codebase and that no external dependencies are broken by this removal.

Poem

🐰 Off hops the lexy library, with DSLs and parsers so grand,
A thousand headers removed from the land,
The codebase grows lighter, the repo more clean,
The simplest refactor this rabbit has seen! 🌿

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely describes the main change: removing the lexy library dependency and replacing it with a hand-written tokenizer and Pratt parser.
Description check	✅ Passed	The description provides a summary of the changes, includes test plans with checkboxes, and mentions generated tool attribution, covering the key modifications and validation approach.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch feature/remove-lexy

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[codacy-production]

Coverage summary from Codacy

See diff coverage on Codacy

Coverage variation	Diff coverage
✅ +2.19% (target: -1.00%)	✅ 95.34%

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (2c71b41)	5395	3755	69.60%
Head commit (847f502)	5782 (+387)	4151 (+396)	71.79% (+2.19%)

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#1099)	451	430	95.34%

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

See your quality gate settings    Change summary preferences

[sonarqubecloud]

Quality Gate passed

Issues
4 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
1.5% Duplication on New Code

See analysis details on SonarQube Cloud