rustfmt.toml

# ============================================================
# Rustfmt configuration for engine.rs
# This file encodes our vertical, declarative, diff-friendly style.
# ============================================================

# Enable unstable features for Nightly
unstable_features = true
style_edition = "2024"
edition = "2024"

# ------------------------------------------------------------
# FUNCTION & BLOCK LAYOUT
# ------------------------------------------------------------

# We prefer block indentation for clarity in nested constructs.
# This keeps macro-heavy and DSL-heavy code visually clean.
indent_style = "Block"

# Multi-argument functions and closures should be tall and readable.
# This dramatically improves scan-ability in command systems and error constructors.
fn_params_layout = "Tall"

# ------------------------------------------------------------
# STRUCTS, LITERALS, AND ALIGNMENT
# ------------------------------------------------------------

# Prevent rustfmt from collapsing structured literals into unreadable one-liners.
# This preserves intentional vertical formatting.
struct_lit_single_line = false

# Avoid alignment columns that become long-term maintenance burdens.
# Zero threshold means: no alignment, ever.
struct_field_align_threshold = 0

# ------------------------------------------------------------
# BUILDER CHAINS & DELIMITED EXPRESSIONS
# ------------------------------------------------------------

# This is especially important for Ariadne/Miette diagnostic builders.
# It keeps each builder step on its own line instead of forcing awkward wrapping.
overflow_delimited_expr = true

# ------------------------------------------------------------
# IMPORT ORGANIZATION
# ------------------------------------------------------------

# Keep imports tidy and avoid rustfmt exploding them into dozens of lines.
imports_granularity = "Crate"

# Group imports in a predictable, modern Rust style.
group_imports = "StdExternalCrate"

# ------------------------------------------------------------
# MATCH & COMMENT BEHAVIOR
# ------------------------------------------------------------

# Keep match arms diff-friendly by allowing trailing commas.
match_block_trailing_comma = true

# Keep comments wrapped to avoid 120-character drift.
wrap_comments = true