1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
|
package repl
import (
"fmt"
"strings"
)
// builtinCommands defines the built-in REPL commands
var builtinCommands = []string{"help", "clear", "quit", "exit"}
// Commands returns the list of built-in command names
func Commands() []string {
return builtinCommands
}
// ExecuteCommand runs a built-in command and returns its output or error
func ExecuteCommand(cmd string) (string, error) {
args := strings.Fields(cmd)
if len(args) == 0 {
return "", nil
}
switch strings.ToLower(args[0]) {
case "help":
return cmdHelp(args[1:]), nil
case "clear":
return "", cmdClear()
case "quit", "exit":
return "", cmdQuit()
default:
return "", fmt.Errorf("unknown command: %s. Available commands: help, clear, quit, exit", args[0])
}
}
func cmdHelp(subCmds []string) string {
helpText := `PERC - Percentage Calculator REPL
Built-in Commands:
help Show this help message
help <command> Show help for a specific topic
clear Clear the screen
quit / exit Exit the REPL
Usage Examples:
20% of 150 Calculate 20% of 150
what is 20% of 150 Same as above (what is prefix is optional)
30 is what % of 150 Calculate what percentage 30 is of 150
30 is 20% of what Calculate what number 30 is 20% of
Keyboard Shortcuts (Vi Mode):
Normal Mode:
i Enter Insert mode
a Append after cursor
0 Move to beginning of line
$ Move to end of line
gg Move to top of history
G Move to bottom of history
Insert Mode:
ESC Return to Normal mode
Ctrl+C Cancel current input
History Navigation:
Up Arrow Previous command
Down Arrow Next command
Press Ctrl+D or type 'quit'/'exit' to exit.
`
if len(subCmds) == 0 {
return helpText
}
subCmd := strings.ToLower(subCmds[0])
switch subCmd {
case "help":
return "help - Show this help message\nUsage: help [command]"
case "clear":
return "clear - Clear the screen\nUsage: clear"
case "quit", "exit":
return "quit / exit - Exit the REPL\nUsage: quit or exit"
default:
return fmt.Sprintf("No help available for: %s\nAvailable commands: help, clear, quit, exit", subCmd)
}
}
func cmdClear() error {
// Clear screen using ANSI escape sequence
fmt.Print("\033[2J\033[H")
return nil
}
func cmdQuit() error {
fmt.Println("Goodbye!")
return nil
}
|
