Function parse 

pub fn parse(
    source: Source,
    options: PreprocessOptions,
) -> Result<PioModule<MulticonductorNetwork>, Error>

Read the initial static GLM electrical profile. Unknown physical classes, properties and globals fail explicitly; they are not silently omitted from an apparently usable network. The source project is retained.

This initial profile covers ordinary phase-to-earth node/load/meter objects, fixed source phasors, P/I/Z loads, overhead and underground line matrices or conductor geometry, and fixed ordinary-phase switch contacts. Finite contacts use exact line equivalents; ideal and open contacts remain typed switches. Ordinary single-phase and three-phase grounded-wye transformers use winding records; FBS additionally preserves its finite default winding-2 core shunt. A connected directed FBS tree may use its implicit upstream voltage source. Wye regulators preserve fixed phase taps, NR resistance and FBS ideal ratios in winding equivalents. Wye capacitors use fixed per-phase shunt admittances. Active controls require explicit individual switch states and produce a frozen-control diagnostic. Delta–grounded-wye transformers use phase-pair primary coils with grounded secondaries, preserving native step-up/down polarity in both solvers. Center-tapped services with grounded neutrals use typed windings and an internal core impedance load; triplex P/I/Z loads retain leg polarity. Triplex geometry uses full conductor matrices with both endpoint neutrals grounded, preserving native hot-conductor and neutral-current behavior. Direct triplex matrices preserve their signed hot-port equations. Canonical grounded service output derives native coefficients from current typed values; floating neutrals and additional service profiles remain unfinished. Standalone substations preserve sequence-derived source phasors. Static reactors use uncoupled lines or ideal contacts, including native NR zero impedance substitution. PNNL constant-PQ generators preserve initialized per-phase injections and ratings. Other device profiles remain unfinished.