Add opposite values and README.md

README.md

@@ -0,0 +1,80 @@
+# scpt
+
+scpt is an applescript-inspired scripting language written for fun and to see if I could.
+
+[![Go Reference](https://pkg.go.dev/badge/gitea.arsenm.dev/Arsen6331/scpt.svg)](https://pkg.go.dev/gitea.arsenm.dev/Arsen6331/scpt)
+
+---
+
+### Usage
+
+scpt is to be used as a library imported into Go. A basic interpreter with no extra functionality would look like this:
+
+```go
+package main
+
+import (
+	"gitea.arsenm.dev/Arsen6331/scpt"
+	"log"
+	"os"
+	"path/filepath"
+)
+
+func main() {
+	filename := os.Args[1]
+	file, err := os.Open(filepath.Clean(filename))
+	if err != nil {
+		log.Fatalln(err)
+	}
+	ast, err := scpt.Parse(file)
+	if err != nil {
+		log.Fatalln(err)
+	}
+	err = ast.Execute()
+	if err != nil {
+		log.Fatalln(err)
+	}
+}
+```
+
+---
+
+### Basic Syntax
+
+The basic syntax of scpt can be learned from the test.scpt file.
+
+---
+
+### Default Functions
+
+scpt comes with the following default functions:
+
+- `str`: Convert value to string
+- `num`: Parse string to number (`float64`)
+- `bool`: Parse string to boolean
+- `break`: Break out of loop (Errors if not in loop)
+- `append`: Return an array with given items appended
+- `exit`: Exit with given exit code
+- `return`: Return value in function (Errors if not within function)
+- `print`: Print using `fmt.Println()`
+
+---
+
+### Adding functionality:
+
+Adding functionality is simple and requires a call to `scpt.AddFuncs()` or `scpt.AddVars()`. Here are some examples:
+
+```go
+scpt.AddFuncs(scpt.FuncMap{
+	"my-function": myFunction
+})
+```
+Where `myFunction` is:
+```go
+func myFunction(args map[string]interface{}) (interface{}, error) {
+	fmt.Println(args)
+	return nil, nil
+}
+```
+
+After the call to `scpt.AddFuncs()`, `my-function` can be used to run the function from within an scpt script. Variables work similarly.

ast.go

@@ -344,6 +344,7 @@ type Value struct {
 	Expr   *Expression  `| "{" @@ "}"`
 	Map    []*MapKVPair `| "[" (@@ ("," @@)* )? "]"`
 	Array  []*Value     `| "[" (@@ ("," @@)* )? "]"`
+	Opposite *Value `| "!" @@`
 }
 
 // Bool stores boolean values encountered while parsing a script.

lexer.go

@@ -24,8 +24,8 @@ var scptLexer = lexer.Must(stateful.NewSimple([]stateful.Rule{
 	{"Ident", `[a-zA-Z_]\w*`, nil},
 	{"String", `"[^"]*"`, nil},
 	{"Number", `(?:\d*\.)?\d+`, nil},
-	{"Punct", `[-[!@$&(){}\|:;"',.?/]|]`, nil},
+	{"Punct", `[![@$&(){}\|:;"',.?]|]`, nil},
 	{"Whitespace", `[ \t\r\n]+`, nil},
 	{"Comment", `(###(.|\n)+###|#[^\n]+)`, nil},
-	{"Operator", `(>=|<=|>|<|==|!=)|[-+*/^%]`, nil},
+	{"Operator", `(>=|<=|>|<|==|!=)|[-+*%/^]`, nil},
 }))

scpt.go

@@ -165,6 +165,16 @@ func ParseValue(val *Value) (interface{}, error) {
 		}
 		// Return map[interface{}]interface{}
 		return iMap, nil
+	} else if val.Opposite != nil {
+		value, err := callIfFunc(ParseValue(val.Opposite))
+		if err != nil {
+			return nil, err
+		}
+		boolean, ok := value.(bool)
+		if !ok {
+			return nil, errors.New("cannot take opposite of a non-boolean value")
+		}
+		return !boolean, nil
 	}
 	return nil, nil
 }