Parametric (for loop) — an ArchLang floor plan example
A row of studio units generated by a for loop over a range: change one constant and the whole row regenerates.
This plan compiles to 3 rooms, 60 m² of floor area and 3 windows; every room is reachable from the entrance.
The source
This is the whole plan. The drawing above is what the compiler produced from it — nothing was drawn by hand.
# Parametric plan (v0.8 scripting): a row of studio units generated with a
# `for` loop over a range, a value-function, an array indexed per unit, a scoped
# `set` rule, an `if`, and string-interpolated labels. Everything is derived
# from the constants — change COUNT and the whole row regenerates.
plan "Parametric — Studio Row" {
units mm
grid 50
scale 1:100
north up
# Plan-level constants (visible everywhere below — plan scope is global).
let WALL = 200
let W = 4000 # unit width
let H = 5000 # unit depth
let DOOR = 900
let WIN = 1600
let COUNT = 3 # number of units
# A value-function (pure closure) — area in square metres.
let aream2(w, h) = w * h / 1000000
# Per-unit names, indexed by the loop variable.
let names = ["Studio A", "Studio B", "Studio C"]
# Entrance doors swing outward throughout this plan (scoped default).
set door(swing: out)
for i in 0..COUNT {
let x = i * W
wall exterior thickness WALL { (x, 0) (x + W, 0) (x + W, H) (x, H) close }
room at (x, 0) size W x H label "{names[i]}"
furniture bed at (x + 300, 300) size 1500x2000 label "Bed"
furniture kitch at (x + W - 1900, 300) size 1600x600 label "Kitchen"
door at (x + W / 2, H) width DOOR wall exterior hinge left
window at (x + W / 2, 0) width WIN wall exterior
# The end unit carries a per-unit area dimension (computed by the function).
# Referenced to the outer face (y = H + WALL/2) so the extension lines start at
# the wall and read downward, away from the building.
if i == COUNT - 1 {
dim (x, H + WALL / 2)->(x + W, H + WALL / 2) offset 600 text "{aream2(W, H)} m² each"
}
}
# Overall run, dimensioned above the building: right-to-left so the offset lands
# ABOVE the row (outside), and referenced to the outer top face (y = -WALL/2).
dim (W * COUNT, 0 - WALL / 2)->(0, 0 - WALL / 2) offset 1300 text "{COUNT} units"
}