You are currently looking at the < v8.2.0 docs (Reason v3.6 syntax edition). You can find the latest API docs here.
(These docs cover all versions between v3 to v8 and are equivalent to the old BuckleScript docs before the rebrand)
Console
Provide console (logging) utilities.
log
let log: 'a => unit;
let log2: ('a, 'b) => unit;
let log3: ('a, 'b, 'c) => unit;
let log4: ('a, 'b, 'c, 'd) => unit;
let logMany: array('a) => unit;
info
let info: 'a => unit;
let info2: ('a, 'b) => unit;
let info3: ('a, 'b, 'c) => unit;
let info4: ('a, 'b, 'c, 'd) => unit;
let infoMany: array('a) => unit;
warn
let warn: 'a => unit;
let warn2: ('a, 'b) => unit;
let warn3: ('a, 'b, 'c) => unit;
let warn4: ('a, 'b, 'c, 'd) => unit;
let warnMany: array('a) => unit;
error
let error: 'a => unit;
let error2: ('a, 'b) => unit;
let error3: ('a, 'b, 'c) => unit;
let error4: ('a, 'b, 'c, 'd) => unit;
let errorMany: array('a) => unit;
trace
let trace: unit => unit;
timeStart
let timeStart: string => unit;
timeEnd
let timeEnd: string => unit;