def text.replace.go

ezsys@0.1.0.0 · src/str.bend:101

import Base

101# the scan for a nonempty `old`; `skip` characters of a found `old` are
102# still to pass over
103def text.replace.go(
104  txt: String,
105  skip: Nat,
106  +old: String,
107  +new: String
108) -> String:
109  match txt skip:
110    case SNil{} _:
111      SNil{}
112    case SCon{_h, t} 1n+k:
113      text.replace.go(t, k, old, new)
114    case SCon{+h, +t} 0n:
115      text.replace.at(String.starts_with(SCon{h, t}, old), h, new,
116        text.after(old),
117        k => text.replace.go(t, k, old, new))