ruler

package main

import (
	"fmt"

	"codeberg.org/japh/psv/internal/ruler"
)

func main() {
	// templates containing invalid characters
	badTemplates := []string{
		`x`,     // `x` does not represent a vertical or horizontal line
		`-`,     // `-` may only be used as a horizontal line - wrong position
		`+x`,    //
		`++`,    // `+` may only be used as a vertical character
		``,      // invalid when explicitly set via WithTemplate
		`|`,     // invalid when explicitly set via WithTemplate
		`+`,     // invalid when explicitly set via WithTemplate
		`+ x`,   //
		`+ |`,   // vertical line instead of a horizontal line
		`| =x`,  //
		`| ==`,  // horizontal line instead of a vertical line -
		`| -|x`, // too long
	}

	for _, t := range badTemplates {
		r := ruler.New()
		err := r.ApplyTemplate(t)
		fmt.Printf("r, err := New(%-7q) => error: %q\n", t, err)
	}

}

Output:

r, err := New("x"    ) => error: "'x' is not a ruler character"
r, err := New("-"    ) => error: "unexpected '-' is not a vertical ruler character for the outer border"
r, err := New("+x"   ) => error: "'x' is not a ruler character"
r, err := New("++"   ) => error: "no horizontal ruler characters found (`-` or `=`)"
r, err := New(""     ) => error: "no ruler characters found"
r, err := New("|"    ) => error: "no horizontal ruler characters found (`-` or `=`)"
r, err := New("+"    ) => error: "no horizontal ruler characters found (`-` or `=`)"
r, err := New("+ x"  ) => error: "'x' is not a ruler character"
r, err := New("+ |"  ) => error: "unexpected '|' is not a horizontal ruler character"
r, err := New("| =x" ) => error: "'x' is not a ruler character"
r, err := New("| ==" ) => error: "unexpected '=' is not a vertical ruler character for column separators"
r, err := New("| -|x") => error: "ruler template is too long \"| -|x\" (max 4 characters)"

package main

import (
	"fmt"

	"codeberg.org/japh/psv/internal/ruler"
)

func main() {
	r := ruler.New()
	err := r.Validate()

	fmt.Printf("r := ruler.New() // preferred default ruler\n")
	fmt.Printf("Default Validation Error: %v\n", err)
	fmt.Printf("Default Template:         %q\n", r.Template())
	fmt.Printf("Default Border Char:      %q\n", r.Border)
	fmt.Printf("Default Padding Char:     %q\n", r.Padding)
	fmt.Printf("Default Horizontal Char:  %q\n", r.Horizontal)
	fmt.Printf("Default Separator Char:   %q\n", r.Separator)

}

Output:

r := ruler.New() // preferred default ruler
Default Validation Error: <nil>
Default Template:         "| -|"
Default Border Char:      '|'
Default Padding Char:     ' '
Default Horizontal Char:  '-'
Default Separator Char:   '|'

package main

import (
	"fmt"

	"codeberg.org/japh/psv/internal/ruler"
)

func main() {
	goodTemplates := []struct {
		template string
		notes    string
	}{
		{"+-", "unpadded"},
		{"|=", "unpadded, emphasised"},
		{"| =", "emphasised"},
		{"+ -|", "custom"},
	}

	for _, t := range goodTemplates {
		r := ruler.New()
		err := r.ApplyTemplate(t.template)
		if err != nil {
			fmt.Printf("r, err := New(%-6q) => unexpected error: %q\n", t.template, err)
			continue
		}
		fmt.Printf("r, err := New(%-6q) => %q %s\n", t.template, r.Template(), t.notes)
	}

}

Output:

r, err := New("+-"  ) => "+--+" unpadded
r, err := New("|="  ) => "|==|" unpadded, emphasised
r, err := New("| =" ) => "| =|" emphasised
r, err := New("+ -|") => "+ -|" custom