Crate dune_raw 

SPICE3 rawfile reader and writer.

The format contract is corpus/spice3f5/src/lib/fte/rawfile.c (raw_write/raw_read, Wayne A. Christopher, 1986): a header of Keyword: value lines (Title, Date, Plotname, Flags, No. Variables, No. Points, optional Dimensions, Command, Option), a Variables: table, and a Values: (ASCII) or Binary: (native-endian f64) data section. One file may carry several plots appended back to back; a plot is complex as a whole if any of its vectors is complex.

The writer reproduces the 3f5 output byte for byte (15-digit %e floats, point index starting each ASCII row, one value per line, a blank line after each point). The reader is deliberately flexible, like the C one: it only requires one Variables: and one data section per plot, in that order, and treats whitespace loosely. Known divergences between 3f5 and ngspice output are listed in docs/dune-raw.md.

Malformed input produces a structured Error with a line number — never a panic.

Structs

Plot

One plot: a header plus a block of data (struct plot in the C).

Rawfile

A parsed rawfile: one or more plots, in file order.

Variable

One variable (a dvec in the 3f5 sources) from the Variables: table.

Enums

Data

Plot data, one column per variable, in Variables: order.

Error

Rawfile reading errors.

Format

Data section encoding. Binary is raw little-endian f64s — the 3f5 writes native doubles, and every platform Dune targets (x86-64, aarch64, wasm32) is little-endian.

VarType

Vector type, as named in the rawfile Variables: table.

Functions

fmt_e

%.*e with the given precision, as C’s printf renders it (1.000000000000000e+03): sign on the exponent, at least two exponent digits. Rust’s {:e} writes 1e3, so this reshapes it. Public because every text surface that mimics the 3f5 (rawfiles, the CLI’s .print columns) needs the same rendering.