96 lines
2.0 KiB
Go
96 lines
2.0 KiB
Go
package parser
|
|
|
|
import "strings"
|
|
|
|
type Scope interface {
|
|
Get(name string) string
|
|
Set(name, value string)
|
|
Call(name string, args []string) string
|
|
SetFunc(name string, f func([]string) string)
|
|
}
|
|
|
|
type scope struct {
|
|
variables map[string]string
|
|
functions map[string]func([]string) string
|
|
parent Scope
|
|
}
|
|
|
|
func (s *scope) Get(name string) string {
|
|
if val, ok := s.variables[name]; ok {
|
|
return val
|
|
} else if s.parent != nil {
|
|
return s.parent.Get(name)
|
|
} else if val, ok := builtinScope[name]; ok {
|
|
return val
|
|
} else {
|
|
return "<'" + name + "' unset>"
|
|
}
|
|
}
|
|
|
|
func (s *scope) Set(name, value string) {
|
|
s.variables[name] = value
|
|
}
|
|
|
|
func (s *scope) Call(name string, args []string) string {
|
|
if f, ok := s.functions[name]; ok {
|
|
return f(args)
|
|
}
|
|
|
|
return "<func:'" + name + "' unset>"
|
|
}
|
|
|
|
func (s *scope) SetFunc(name string, f func([]string) string) {
|
|
s.functions[name] = f
|
|
}
|
|
|
|
func NewScope(parent Scope) Scope {
|
|
return &scope{
|
|
variables: make(map[string]string),
|
|
functions: make(map[string]func([]string) string),
|
|
parent: parent,
|
|
}
|
|
}
|
|
|
|
var builtinScope map[string]string
|
|
|
|
func init() {
|
|
builtinScope := make(map[string]string)
|
|
builtinScope["__builtin_dollar"] = "$"
|
|
}
|
|
|
|
func (v Variable) EvalFunction(scope Scope) (string, bool) {
|
|
f := v.Name.SplitN(" \t", 2)
|
|
if len(f) > 1 && f[0].Const() {
|
|
fname := f[0].Value(nil)
|
|
if isFunctionName(fname) {
|
|
args := f[1].Split(",")
|
|
argVals := make([]string, len(args))
|
|
for i, a := range args {
|
|
argVals[i] = a.Value(scope)
|
|
}
|
|
|
|
if fname == "call" {
|
|
return scope.Call(argVals[0], argVals[1:]), true
|
|
} else {
|
|
return "__builtin_func:" + fname + " " + strings.Join(argVals, " "), true
|
|
}
|
|
}
|
|
}
|
|
|
|
return "", false
|
|
}
|
|
|
|
func (v Variable) Value(scope Scope) string {
|
|
if ret, ok := v.EvalFunction(scope); ok {
|
|
return ret
|
|
}
|
|
return scope.Get(v.Name.Value(scope))
|
|
}
|
|
|
|
func toVariable(ms *MakeString) (Variable, bool) {
|
|
if len(ms.Variables) == 1 && ms.Strings[0] == "" && ms.Strings[1] == "" {
|
|
return ms.Variables[0], true
|
|
}
|
|
return Variable{}, false
|
|
}
|