import std/macros
import std/options
import std/tables
import std/unicode
import bindings/quickjs
import js/jserror
import js/jstypes
import js/jsopaque
import types/opt
import utils/twtstr
proc fromJS*[T](ctx: JSContext; val: JSValue): JSResult[T]
func isInstanceOfNonGlobal(ctx: JSContext; val: JSValue; class: string): bool =
let ctxOpaque = ctx.getOpaque()
var classid = JS_GetClassID(val)
let tclassid = ctxOpaque.creg[class]
var found = false
while true:
if classid == tclassid:
found = true
break
ctxOpaque.parents.withValue(classid, val):
classid = val[]
do:
classid = 0 # not defined by Chawan; assume parent is Object.
if classid == 0:
break
return found
func isInstanceOfGlobal(ctx: JSContext; val: JSValue; class: string): bool =
let ctxOpaque = ctx.getOpaque()
#TODO gparent only works for a single level. (But this is not really a
# problem right now, because our global objects have at most one inheritance
# level.)
if ctx.isGlobal(class) or ctxOpaque.creg[class] == ctxOpaque.gparent:
# undefined -> global
if JS_IsUndefined(val):
return true
if JS_IsObject(val):
let global = JS_GetGlobalObject(ctx)
let p0 = JS_VALUE_GET_PTR(global)
let p1 = JS_VALUE_GET_PTR(val)
JS_FreeValue(ctx, global)
if p0 == p1:
return true
return false
func isInstanceOf*(ctx: JSContext; val: JSValue; class: string): bool =
return ctx.isInstanceOfGlobal(val, class) or
ctx.isInstanceOfNonGlobal(val, class)
func toString(ctx: JSContext; val: JSValue): Opt[string] =
var plen: csize_t
let outp = JS_ToCStringLen(ctx, addr plen, val) # cstring
if outp != nil:
var ret = newString(plen)
if plen != 0:
prepareMutation(ret)
copyMem(addr ret[0], outp, plen)
result = ok(ret)
JS_FreeCString(ctx, outp)
func fromJSString(ctx: JSContext; val: JSValue): JSResult[string] =
var plen: csize_t
let outp = JS_ToCStringLen(ctx, addr plen, val) # cstring
if outp == nil:
return err()
var ret = newString(plen)
if plen != 0:
prepareMutation(ret)
copyMem(addr ret[0], outp, plen)
JS_FreeCString(ctx, outp)
return ok(ret)
func fromJSInt[T: SomeInteger](ctx: JSContext; val: JSValue):
JSResult[T] =
when T is int:
# Always int32, so we don't risk 32-bit only breakage.
# If int64 is needed, specify it explicitly.
var ret: int32
if JS_ToInt32(ctx, addr ret, val) < 0:
return err()
return ok(int(ret))
elif T is int32:
var ret: int32
if JS_ToInt32(ctx, addr ret, val) < 0:
return err()
return ok(ret)
elif T is int64:
var ret: int64
if JS_ToInt64(ctx, addr ret, val) < 0:
return err()
return ok(ret)
elif T is uint32:
var ret: uint32
if JS_ToUint32(ctx, addr ret, val) < 0:
return err()
return ok(ret)
else:
static:
error($T & " cannot be converted to JS automatically")
proc fromJSFloat64(ctx: JSContext; val: JSValue): JSResult[float64] =
var f64: float64
if JS_ToFloat64(ctx, addr f64, val) < 0:
return err()
return ok(f64)
macro fromJSTupleBody(a: tuple) =
let len = a.getType().len - 1
let done = ident("done")
result = newStmtList(quote do:
var `done`: bool)
for i in 0..<len:
result.add(quote do:
let next = JS_Call(ctx, nextMethod, it, 0, nil)
if JS_IsException(next):
return err()
defer: JS_FreeValue(ctx, next)
let doneVal = JS_GetProperty(ctx, next, ctx.getOpaque().strRefs[jstDone])
if JS_IsException(doneVal):
return err()
defer: JS_FreeValue(ctx, doneVal)
`done` = ?fromJS[bool](ctx, doneVal)
if `done`:
return errTypeError("Too few arguments in sequence (got " & $`i` &
", expected " & $`len` & ")")
let valueVal = JS_GetProperty(ctx, next, ctx.getOpaque().strRefs[jstValue])
if JS_IsException(valueVal):
return err()
defer: JS_FreeValue(ctx, valueVal)
`a`[`i`] = ?fromJS[typeof(`a`[`i`])](ctx, valueVal)
)
if i == len - 1:
result.add(quote do:
let next = JS_Call(ctx, nextMethod, it, 0, nil)
if JS_IsException(next):
return err()
defer: JS_FreeValue(ctx, next)
let doneVal = JS_GetProperty(ctx, next, ctx.getOpaque().strRefs[jstDone])
`done` = ?fromJS[bool](ctx, doneVal)
var i = `i`
# we're emulating a sequence, so we must query all remaining parameters
# too:
while not `done`:
inc i
let next = JS_Call(ctx, nextMethod, it, 0, nil)
if JS_IsException(next):
return err()
defer: JS_FreeValue(ctx, next)
let doneVal = JS_GetProperty(ctx, next,
ctx.getOpaque().strRefs[jstDone])
if JS_IsException(doneVal):
return err()
defer: JS_FreeValue(ctx, doneVal)
`done` = ?fromJS[bool](ctx, doneVal)
if `done`:
let msg = "Too many arguments in sequence (got " & $i &
", expected " & $`len` & ")"
return err(newTypeError(msg))
JS_FreeValue(ctx, JS_GetProperty(ctx, next,
ctx.getOpaque().strRefs[jstValue]))
)
proc fromJSTuple[T: tuple](ctx: JSContext; val: JSValue): JSResult[T] =
let itprop = JS_GetProperty(ctx, val, ctx.getOpaque().symRefs[jsyIterator])
if JS_IsException(itprop):
return err()
defer: JS_FreeValue(ctx, itprop)
let it = JS_Call(ctx, itprop, val, 0, nil)
if JS_IsException(it):
return err()
defer: JS_FreeValue(ctx, it)
let nextMethod = JS_GetProperty(ctx, it, ctx.getOpaque().strRefs[jstNext])
if JS_IsException(nextMethod):
return err()
defer: JS_FreeValue(ctx, nextMethod)
var x: T
fromJSTupleBody(x)
return ok(x)
proc fromJSSeq[T](ctx: JSContext; val: JSValue): JSResult[seq[T]] =
let itprop = JS_GetProperty(ctx, val, ctx.getOpaque().symRefs[jsyIterator])
if JS_IsException(itprop):
return err()
defer: JS_FreeValue(ctx, itprop)
let it = JS_Call(ctx, itprop, val, 0, nil)
if JS_IsException(it):
return err()
defer: JS_FreeValue(ctx, it)
let nextMethod = JS_GetProperty(ctx, it, ctx.getOpaque().strRefs[jstNext])
if JS_IsException(nextMethod):
return err()
defer: JS_FreeValue(ctx, nextMethod)
var s = newSeq[T]()
while true:
let next = JS_Call(ctx, nextMethod, it, 0, nil)
if JS_IsException(next):
return err()
defer: JS_FreeValue(ctx, next)
let doneVal = JS_GetProperty(ctx, next, ctx.getOpaque().strRefs[jstDone])
if JS_IsException(doneVal):
return err()
defer: JS_FreeValue(ctx, doneVal)
let done = ?fromJS[bool](ctx, doneVal)
if done:
break
let valueVal = JS_GetProperty(ctx, next, ctx.getOpaque().strRefs[jstValue])
if JS_IsException(valueVal):
return err()
defer: JS_FreeValue(ctx, valueVal)
let genericRes = ?fromJS[typeof(s[0])](ctx, valueVal)
s.add(genericRes)
return ok(s)
proc fromJSSet[T](ctx: JSContext; val: JSValue): JSResult[set[T]] =
let itprop = JS_GetProperty(ctx, val, ctx.getOpaque().symRefs[jsyIterator])
if JS_IsException(itprop):
return err()
defer: JS_FreeValue(ctx, itprop)
let it = JS_Call(ctx, itprop, val, 0, nil)
if JS_IsException(it):
return err()
defer: JS_FreeValue(ctx, it)
let nextMethod = JS_GetProperty(ctx, it, ctx.getOpaque().strRefs[jstNext])
if JS_IsException(nextMethod):
return err()
defer: JS_FreeValue(ctx, nextMethod)
var s: set[T]
while true:
let next = JS_Call(ctx, nextMethod, it, 0, nil)
if JS_IsException(next):
return err()
defer: JS_FreeValue(ctx, next)
let doneVal = JS_GetProperty(ctx, next, ctx.getOpaque().strRefs[jstDone])
if JS_IsException(doneVal):
return err()
defer: JS_FreeValue(ctx, doneVal)
let done = ?fromJS[bool](ctx, doneVal)
if done:
break
let valueVal = JS_GetProperty(ctx, next, ctx.getOpaque().strRefs[jstValue])
if JS_IsException(valueVal):
return err()
defer: JS_FreeValue(ctx, valueVal)
let genericRes = ?fromJS[T](ctx, valueVal)
s.incl(genericRes)
return ok(s)
proc fromJSTable[A, B](ctx: JSContext; val: JSValue): JSResult[Table[A, B]] =
if not JS_IsObject(val):
return err(newTypeError("object expected"))
var ptab: ptr UncheckedArray[JSPropertyEnum]
var plen: uint32
let flags = cint(JS_GPN_STRING_MASK)
if JS_GetOwnPropertyNames(ctx, addr ptab, addr plen, val, flags) == -1:
# exception
return err()
defer:
for i in 0 ..< plen:
JS_FreeAtom(ctx, ptab[i].atom)
js_free(ctx, ptab)
var res = Table[A, B]()
for i in 0 ..< plen:
let atom = ptab[i].atom
let k = JS_AtomToValue(ctx, atom)
defer: JS_FreeValue(ctx, k)
let kn = ?fromJS[A](ctx, k)
let v = JS_GetProperty(ctx, val, atom)
defer: JS_FreeValue(ctx, v)
let vn = ?fromJS[B](ctx, v)
res[kn] = vn
return ok(res)
template optionType[T](o: type Option[T]): auto =
T
# Option vs Opt:
# Option is for nullable types, e.g. if you want to return either a string
# or null. (This is rather pointless for anything else.)
# Opt is for passing down exceptions received up in the chain.
# So e.g. none(T) translates to JS_NULL, but err() translates to JS_EXCEPTION.
proc fromJSOption[T](ctx: JSContext; val: JSValue): JSResult[Option[T]] =
if JS_IsNull(val):
return ok(none(T))
let res = ?fromJS[T](ctx, val)
return ok(option(res))
proc fromJSBool(ctx: JSContext; val: JSValue): JSResult[bool] =
let ret = JS_ToBool(ctx, val)
if ret == -1: # exception
return err()
if ret == 0:
return ok(false)
return ok(true)
proc fromJSEnum[T: enum](ctx: JSContext; val: JSValue): JSResult[T] =
if JS_IsException(val):
return err()
let s = ?toString(ctx, val)
let r = strictParseEnum[T](s)
if r.isSome:
return ok(r.get)
return errTypeError("`" & s & "' is not a valid value for enumeration " & $T)
proc fromJSPObj0(ctx: JSContext; val: JSValue; t: string):
JSResult[pointer] =
if JS_IsException(val):
return err(nil)
if JS_IsNull(val):
return ok(nil)
if ctx.isInstanceOfGlobal(val, t):
return ok(?getGlobalOpaque0(ctx, val))
if not JS_IsObject(val):
return err(newTypeError("Value is not an object"))
if not isInstanceOfNonGlobal(ctx, val, t):
return errTypeError(t & " expected")
let classid = JS_GetClassID(val)
let op = JS_GetOpaque(val, classid)
return ok(op)
proc fromJSObject[T: ref object](ctx: JSContext; val: JSValue): JSResult[T] =
return ok(cast[T](?fromJSPObj0(ctx, val, $T)))
proc fromJSVoid(ctx: JSContext; val: JSValue): JSResult[void] =
if JS_IsException(val):
return err()
return ok()
proc fromJSDict[T: JSDict](ctx: JSContext; val: JSValue): JSResult[T] =
if not JS_IsUndefined(val) and not JS_IsNull(val) and not JS_IsObject(val):
return err(newTypeError("Dictionary is not an object"))
#TODO throw on missing required values
var d = T()
if JS_IsObject(val):
for k, v in d.fieldPairs:
let esm = JS_GetPropertyStr(ctx, val, k)
if not JS_IsUndefined(esm):
v = ?fromJS[typeof(v)](ctx, esm)
when v isnot JSValue:
JS_FreeValue(ctx, esm)
return ok(d)
proc fromJSArrayBuffer(ctx: JSContext; val: JSValue): JSResult[JSArrayBuffer] =
var len: csize_t
let p = JS_GetArrayBuffer(ctx, addr len, val)
if p == nil:
return err()
let abuf = JSArrayBuffer(
len: len,
p: cast[ptr UncheckedArray[uint8]](p)
)
return ok(abuf)
proc fromJSArrayBufferView(ctx: JSContext; val: JSValue):
JSResult[JSArrayBufferView] =
var offset: csize_t
var nmemb: csize_t
var nsize: csize_t
let jsbuf = JS_GetTypedArrayBuffer(ctx, val, addr offset, addr nmemb,
addr nsize)
let abuf = ?fromJSArrayBuffer(ctx, jsbuf)
let view = JSArrayBufferView(
abuf: abuf,
offset: offset,
nmemb: nmemb,
nsize: nsize
)
return ok(view)
type FromJSAllowedT = (object and not (Result|Option|Table|JSValue|JSDict|
JSArrayBuffer|JSArrayBufferView|JSUint8Array))
macro fromJS2(ctx: JSContext; val: JSValue; x: static string): untyped =
let id = ident("fromJS" & x)
return quote do:
`id`(`ctx`, `val`)
proc fromJS*[T](ctx: JSContext; val: JSValue): JSResult[T] =
when T is string:
return fromJSString(ctx, val)
elif T is Option:
return fromJSOption[optionType(T)](ctx, val)
elif T is seq:
return fromJSSeq[typeof(result.get.items)](ctx, val)
elif T is set:
return fromJSSet[typeof(result.get.items)](ctx, val)
elif T is tuple:
return fromJSTuple[T](ctx, val)
elif T is bool:
return fromJSBool(ctx, val)
elif typeof(result).valType is Table:
return fromJSTable[typeof(result.get.keys),
typeof(result.get.values)](ctx, val)
elif T is SomeInteger:
return fromJSInt[T](ctx, val)
elif T is float64:
return fromJSFloat64(ctx, val)
elif T is enum:
return fromJSEnum[T](ctx, val)
elif T is JSValue:
return ok(val)
elif T is ref object:
return fromJSObject[T](ctx, val)
elif T is void:
return fromJSVoid(ctx, val)
elif T is JSDict:
return fromJSDict[T](ctx, val)
elif T is JSArrayBuffer:
return fromJSArrayBuffer(ctx, val)
elif T is JSArrayBufferView:
return fromJSArrayBufferView(ctx, val)
else:
return fromJS2(ctx, val, $T)
const JS_ATOM_TAG_INT = 1u32 shl 31
func JS_IsNumber*(v: JSAtom): JS_BOOL =
return (uint32(v) and JS_ATOM_TAG_INT) != 0
func fromJS*[T: string|uint32|JSAtom](ctx: JSContext; atom: JSAtom): Opt[T] =
when T is JSAtom:
return ok(atom)
elif T is SomeNumber:
if JS_IsNumber(atom):
return ok(uint32(atom) and (not JS_ATOM_TAG_INT))
return err()
else:
let cs = JS_AtomToCString(ctx, atom)
if cs == nil:
return err()
let s = $cs
JS_FreeCString(ctx, cs)
return ok(s)
proc fromJSPObj[T](ctx: JSContext; val: JSValue): JSResult[ptr T] =
return cast[JSResult[ptr T]](fromJSPObj0(ctx, val, $T))
template fromJSP*[T](ctx: JSContext; val: JSValue): untyped =
when T is FromJSAllowedT:
fromJSPObj[T](ctx, val)
else:
fromJS[T](ctx, val)