msi-rs

Rust port of EPICS msi (Macro Substitution and Include) — converts .template files to .db files by expanding macros and processing include/substitute directives.

No EPICS dependencies. Pure text processing.

Output is identical to C msi for ADCore/ADSimDetector templates (verified by golden tests).

Repository: https://github.com/epics-rs/epics-rs

CLI

# Build the CLI
cargo build -p msi-rs --features cli

# Expand template with macros
msi-rs -M "P=IOC:,R=ai1" template.template

# Use substitution file
msi-rs -S subst.substitutions

# With include paths and output file
msi-rs -I ./includes -M "P=IOC:" template.template -o output.db

# Strict mode: fail on undefined macros
msi-rs -V -M "P=IOC:" template.template

Options

Flag	Description
`-M A=val,B=val`	Macro definitions (comma-separated)
`-S FILE`	Substitution file
`-I DIR`	Include search directory (repeatable)
`-o FILE`	Output file (default: stdout)
`-V`	Strict mode: report undefined macros as errors

Library API

use std::path::Path;
use msi_rs::{expand_template, MacHandle, TemplateProcessor};

// Simple: expand template with macros
let output = expand_template(
    Path::new("template.template"),
    &[("P", "IOC:"), ("R", "ai1")],
    &[],  // include paths
)?;

// Advanced: use MacHandle directly
let mut mac = MacHandle::new();
mac.install_macros("P=IOC:,R=ai1");
let expanded = mac.expand_string("$(P)$(R)");

Macro Syntax

Syntax	Description
`$(NAME)`	Basic macro reference
`${NAME}`	Brace variant (equivalent)
`$(NAME=default)`	Default value if undefined
`$(NAME,SUB=val)`	Scoped macro definition
`$(A$(B))`	Nested macro reference
`'$(NAME)'`	Single-quote suppression
`\$(NAME)`	Backslash escape

Template Directives

include "path/to/file.template"
substitute "A=val,B=val2"

Include paths are resolved using -I directories
Maximum include depth: 20 (prevents infinite loops)

Substitution File Format

file "template.template" {
    # Pattern block: column names + value rows
    pattern { P, R }
    { "IOC:", "ai1" }
    { "IOC:", "ai2" }
}

# Global macros apply to all subsequent sets
global { SCAN = "1 second" }

# Regular block: key=value pairs
{ P = "IOC:", R = "ao1" }

Build

cargo build -p msi-rs                  # library only
cargo build -p msi-rs --features cli   # library + CLI binary
cargo test -p msi-rs                   # 57 tests

License

MIT

msi-rs 0.6.0