feat: execute code on slides

examples/code_blocks.md

@@ -0,0 +1,50 @@
+# Code blocks
+
+Slides allows you to execute code blocks directly inside your slides!
+
+Just press `e` and the result of the code block will be displayed as virtual
+text in your slides.
+
+Currently supported languages:
+* `bash`
+* `go`
+* `ruby`
+* `python`
+
+---
+
+### Bash
+
+```bash
+ls
+```
+
+---
+
+### Go
+
+```go
+package main
+
+import "fmt"
+
+func main() {
+  fmt.Println("Hello, world!")
+}
+```
+
+---
+
+### Ruby
+
+```ruby
+puts "Hello, world!"
+```
+
+---
+
+### Python
+
+```python
+print("Hello, world!")
+```

internal/code/code.go

@@ -21,7 +21,7 @@ type Result struct {
 }
 
 // ?: means non-capture group
-var re = regexp.MustCompile("(?:```|~~~)(.*)\n(.*)\n(?:```|~~~)")
+var re = regexp.MustCompile("(?s)(?:```|~~~)(\\w+)\n(.*)\n(?:```|~~~)\n")
 
 var (
 	ErrParse = errors.New("Error: could not parse code block")

internal/code/code_test.go

@@ -37,28 +37,38 @@ fmt.Println("Hello, world!")
 		},
 		{
 			markdown: `
-# Slide 1
-Just a regular slide, no code block
-`,
-			expected: code.Block{},
-		},
-		{
-			markdown: `
-# Multiple Code Blocks
+# Welcome to Slides
+
+A terminal based presentation tool
+
 ~~~go
-fmt.Println("Oh no!")
-~~~
+package main
 
-# Secondary Code Block
-~~~ruby
-puts "We will only parse the first code block"
+import "fmt"
+
+func main() {
+  fmt.Println("Written in Go!")
+}
 ~~~
 `,
 			expected: code.Block{
-				Code:     `fmt.Println("Oh no!")`,
+				Code: `package main
+
+import "fmt"
+
+func main() {
+  fmt.Println("Written in Go!")
+}`,
 				Language: "go",
 			},
 		},
+		{
+			markdown: `
+# Slide 1
+Just a regular slide, no code block
+`,
+			expected: code.Block{},
+		},
 		{
 			markdown: ``,
 			expected: code.Block{},

internal/model/model.go

@@ -7,6 +7,7 @@ import (
 	"github.com/charmbracelet/bubbles/viewport"
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/glamour"
+	"github.com/maaslalani/slides/internal/code"
 	"github.com/maaslalani/slides/internal/meta"
 	"github.com/maaslalani/slides/styles"
 	"io"
@@ -29,6 +30,9 @@ type Model struct {
 	Theme    glamour.TermRendererOption
 	FileName string
 	viewport viewport.Model
+	// VirtualText is used for additional information that is not part of the
+	// original slides, it will be displayed on a slide and reset on page change
+	VirtualText string
 }
 
 type fileWatchMsg struct{}
@@ -96,10 +100,22 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			if m.Page < len(m.Slides)-1 {
 				m.Page++
 			}
+			m.VirtualText = ""
 		case "up", "j", "left", "h", "p":
 			if m.Page > 0 {
 				m.Page--
 			}
+			m.VirtualText = ""
+		case "e":
+			// Run code block
+			block, err := code.Parse(m.Slides[m.Page])
+			if err != nil {
+				// We couldn't parse the code block on the screen
+				m.VirtualText = "\n" + err.Error()
+				return m, nil
+			}
+			res := code.Execute(block)
+			m.VirtualText = res.Out
 		}
 
 	case fileWatchMsg:
@@ -118,7 +134,9 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 
 func (m Model) View() string {
 	r, _ := glamour.NewTermRenderer(m.Theme, glamour.WithWordWrap(0))
-	slide, err := r.Render(m.Slides[m.Page])
+	slide := m.Slides[m.Page]
+	slide += m.VirtualText
+	slide, err := r.Render(slide)
 	if err != nil {
 		slide = fmt.Sprintf("Error: Could not render markdown! (%v)", err)
 	}