Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Simplify the way that hashes are evaluated. #96

Merged
merged 1 commit into from
Nov 13, 2022
Merged

Simplify the way that hashes are evaluated. #96

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
67 changes: 32 additions & 35 deletions eval/eval.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -125,7 +125,7 @@ func (ev *Eval) Evaluate(e *env.Environment) primitive.Primitive {
// loop over all input
for {
// Get the next expression
expr, err := ev.readExpression()
expr, err := ev.readExpression(e)

if err != nil {
// End of list?
Expand Down Expand Up @@ -291,7 +291,7 @@ func (ev *Eval) eval(exp primitive.Primitive, e *env.Environment, expandMacro bo
// Behaviour depends on the type of the primitive/expression
// we've been given to execute.
//
switch obj := exp.(type) {
switch exp.(type) {

// Booleans return themselves
case primitive.Bool:
Expand All @@ -305,20 +305,9 @@ func (ev *Eval) eval(exp primitive.Primitive, e *env.Environment, expandMacro bo
case primitive.Error:
return exp

// Hashes return themselves, but the values should be
// evaluated - see #8.
// Hashes return themselves
case primitive.Hash:
ret := primitive.NewHash()

for x, y := range obj.Entries {

val := ev.eval(y, e, expandMacro)

ret.Set(x, val)
}

ret.SetStruct(obj.GetStruct())
return ret
return exp

// Numbers return themselves
case primitive.Number:
Expand Down Expand Up @@ -419,7 +408,7 @@ func (ev *Eval) eval(exp primitive.Primitive, e *env.Environment, expandMacro bo
//
// So we don't need an environment, etc.
//
out, err := tmp.readExpression()
out, err := tmp.readExpression(e)
if err != nil {
return primitive.Error(fmt.Sprintf("failed to read %s:%s", arg, err.Error()))
}
Expand Down Expand Up @@ -895,29 +884,32 @@ func (ev *Eval) eval(exp primitive.Primitive, e *env.Environment, expandMacro bo
// Is this a type-check on a struct?
if strings.HasSuffix(thing.ToString(), "?") {

// We're looking for a function-call
// that has a trailing "?", and one
// argument
if len(listExp) != 2 {
return primitive.ArityError()
}

// Get the thing that is being tested.
typeName := strings.TrimSuffix(thing.ToString(), "?")

// Does that represent a known-type?
_, ok2 := ev.structs[typeName]
if ok2 {

// OK now we're sure we're not colliding
// with another function test the argument
// count.
if len(listExp) != 2 {
return primitive.ArityError()
}

// OK a type-check on a known struct
//
// Note we evaluate the object
// Note we evaluate the object, because it
// was probably a symbol, or return object
// of some kind.
obj := ev.eval(listExp[1], e, expandMacro)

// is it a hash?
hsh, ok2 := obj.(primitive.Hash)
if !ok2 {
// nope - then not a struct
// nope - if it isn't a hash
// then it can't be a struct.
return primitive.Bool(false)
}

Expand All @@ -930,7 +922,9 @@ func (ev *Eval) eval(exp primitive.Primitive, e *env.Environment, expandMacro bo

// just a method call with a trailing "?".
//
// could be "string?", etc, so we fall-through
// could be "string?", "contains?", etc,
// so we fall-through and keep processing as
// per usual.
}

// Find the thing we're gonna call.
Expand Down Expand Up @@ -1213,7 +1207,7 @@ func (ev *Eval) quasiquote(exp primitive.Primitive) primitive.Primitive {

// readExpression uses recursion to read a complete expression from
// our internal array of tokens - as produced by `tokenize`.
func (ev *Eval) readExpression() (primitive.Primitive, error) {
func (ev *Eval) readExpression(e *env.Environment) (primitive.Primitive, error) {

// Have we walked off the end of the program?
if ev.offset >= len(ev.toks) {
Expand All @@ -1229,31 +1223,31 @@ func (ev *Eval) readExpression() (primitive.Primitive, error) {
switch token {
case "'":
// '... => (quote ...)
quoted, err := ev.readExpression()
quoted, err := ev.readExpression(e)
if err != nil {
return nil, err
}
return primitive.List{ev.atom("quote"), quoted}, nil

case "`":
// `... => (quasiquote ...)
quoted, err := ev.readExpression()
quoted, err := ev.readExpression(e)
if err != nil {
return nil, err
}
return primitive.List{ev.atom("quasiquote"), quoted}, nil

case "~", ",":
// ~... => (unquote ...)
quoted, err := ev.readExpression()
quoted, err := ev.readExpression(e)
if err != nil {
return nil, err
}
return primitive.List{ev.atom("unquote"), quoted}, nil

case "~@", "`,", ",@":
// ~@... => (splice-unquote ...)
quoted, err := ev.readExpression()
quoted, err := ev.readExpression(e)
if err != nil {
return nil, err
}
Expand All @@ -1275,7 +1269,7 @@ func (ev *Eval) readExpression() (primitive.Primitive, error) {
for ev.toks[ev.offset] != ")" {

// Read the sub-expressions, recursively.
expr, err := ev.readExpression()
expr, err := ev.readExpression(e)
if err != nil {
return nil, err
}
Expand Down Expand Up @@ -1309,7 +1303,7 @@ func (ev *Eval) readExpression() (primitive.Primitive, error) {
for ev.toks[ev.offset] != "}" {

// Read the sub-expressions, recursively.
key, err := ev.readExpression()
key, err := ev.readExpression(e)
if err != nil {
return nil, err
}
Expand All @@ -1320,7 +1314,7 @@ func (ev *Eval) readExpression() (primitive.Primitive, error) {
}

// Read the sub-expressions, recursively.
val, err2 := ev.readExpression()
val, err2 := ev.readExpression(e)
if err2 != nil {
return nil, err2
}
Expand All @@ -1330,7 +1324,10 @@ func (ev *Eval) readExpression() (primitive.Primitive, error) {
return nil, ErrEOF
}

hash.Set(key.ToString(), val)
// Ensure the value is evaluated
v := ev.eval(val, e, true)

hash.Set(key.ToString(), v)
}

// We bump the current read-position one more here,
Expand Down