Added element function generator

elements.go

@@ -0,0 +1,44 @@
+// GENERATED BY gitlab.codemonkeysoftware.net/b/hatmill/internal/elementgen
+// DO NOT EDIT!
+
+package hatmill
+
+func Div(attribs ...Attrib) func(children ...Term) *ParentElement {
+	return func(children ...Term) *ParentElement {
+		return &ParentElement{
+			EmptyElement: EmptyElement{
+				TagName: "div",
+				Attribs: attribs,
+			},
+			Children: children,
+		}
+	}
+}
+func Img(attribs ...Attrib) EmptyElement {
+	return EmptyElement{
+		TagName: "img",
+		Attribs: attribs,
+	}
+}
+func Span(attribs ...Attrib) func(children ...Term) *ParentElement {
+	return func(children ...Term) *ParentElement {
+		return &ParentElement{
+			EmptyElement: EmptyElement{
+				TagName: "span",
+				Attribs: attribs,
+			},
+			Children: children,
+		}
+	}
+}
+func Html(attribs ...Attrib) func(children ...Term) *ParentElement {
+	return func(children ...Term) *ParentElement {
+		return &ParentElement{
+			EmptyElement: EmptyElement{
+				TagName: "html",
+				Attribs: attribs,
+			},
+			Children: children,
+		}
+	}
+}

elements.txt

@@ -0,0 +1,4 @@
+div parent
+img empty
+span parent
+html parent

example/example.go

@@ -0,0 +1,17 @@
+package main
+
+import (
+    "os"
+    h "gitlab.codemonkeysoftware.com/b/hatmill"
+)
+
+func main() {
+    document := h.Html()(
+        h.Div()(
+            h.Img(h.Id("profile-photo")),
+            h.Text("hello hatmill!"),
+            h.Div(h.Disabled())(),
+        ),
+    )
+    h.WriteDocument(os.Stdout, document)
+}

hatmill.go

@@ -2,11 +2,13 @@ package hatmill
 
 import "io"
 
-// Html is one of EmptyElement, ParentElement, or Text.
+//go:generate go run ./internal/elementgen/main.go
-type Html interface {
+
+// Term represents a fragment of HTML markup, and is one of EmptyElement, ParentElement, or Text.
+type Term interface {
 	io.WriterTo
 
-	// isHtml is a no-op method to prevent external Html implementations, because
+	// isHtml is a no-op method to prevent external Term implementations, because
 	// Go doesn't have sum types.
 	isHtml()
 }
@@ -73,7 +75,7 @@ func (e EmptyElement) WriteTo(w io.Writer) (n int64, err error) {
 
 type ParentElement struct {
 	EmptyElement
-	Children []Html
+	Children []Term
 }
 
 func (e *ParentElement) isHtml() {}
@@ -108,24 +110,24 @@ func (t Text) WriteTo(w io.Writer) (n int64, err error) {
 
 // Html5 functions
 
-func Div(attribs ...Attrib) func(children ...Html) *ParentElement {
+// func Div(attribs ...Attrib) func(children ...Term) *ParentElement {
-	return func(children ...Html) *ParentElement {
+// 	return func(children ...Term) *ParentElement {
-		return &ParentElement{
+// 		return &ParentElement{
-			EmptyElement: EmptyElement{
+// 			EmptyElement: EmptyElement{
-				TagName: "div",
+// 				TagName: "div",
-				Attribs: attribs,
+// 				Attribs: attribs,
-			},
+// 			},
-			Children: children,
+// 			Children: children,
-		}
+// 		}
-	}
+// 	}
-}
+// }
-
+//
-func Img(attribs ...Attrib) EmptyElement {
+// func Img(attribs ...Attrib) EmptyElement {
-	return EmptyElement{
+// 	return EmptyElement{
-		TagName: "img",
+// 		TagName: "img",
-		Attribs: attribs,
+// 		Attribs: attribs,
-	}
+// 	}
-}
+// }
 
 func Id(id string) Attrib {
 	return Attrib{

hatmill_test.go

@@ -122,7 +122,7 @@ func TestEmptyElement(t *testing.T) {
     properties.TestingRun(t)
 }
 
-var htmlTextGen = gen.AnyString().Map(func(s string) hatmill.Html {
+var htmlTextGen = gen.AnyString().Map(func(s string) hatmill.Term {
     return hatmill.Text(s)
 })
 
@@ -147,7 +147,7 @@ func TestParentElement(t *testing.T) {
     ))
 
     properties.Property("WriteTo writes element correctly with children", prop.ForAll(
-        func(tagName string, attribs []hatmill.Attrib, children []hatmill.Html) bool {
+        func(tagName string, attribs []hatmill.Attrib, children []hatmill.Term) bool {
             elem := &hatmill.ParentElement {
                 EmptyElement: hatmill.EmptyElement{
                     TagName: tagName,

internal/elementgen/main.go

@@ -0,0 +1,93 @@
+package main
+
+import (
+    "bufio"
+    "bytes"
+    "fmt"
+    "go/format"
+    "io/ioutil"
+    "log"
+    "os"
+    "strings"
+)
+
+const (
+    inputPath = "elements.txt"
+    outputPath = "elements.go"
+    packageName = "hatmill"
+
+    parentType = "parent"
+    emptyType = "empty"
+
+    parentTemplate = `func %s(attribs ...Attrib) func(children ...Term) *ParentElement {
+        return func(children ...Term) *ParentElement {
+            return &ParentElement{
+    			EmptyElement: EmptyElement{
+    				TagName: "%s",
+    				Attribs: attribs,
+    			},
+    			Children: children,
+    		}
+        }
+    }
+    `
+    emptyTemplate = `func %s(attribs ...Attrib) EmptyElement {
+        return EmptyElement{
+			TagName: "%s",
+			Attribs: attribs,
+		}
+    }
+    `
+)
+
+func main() {
+    inputFile, err := os.Open(inputPath)
+    if err != nil {
+        log.Fatal(err)
+    }
+    defer inputFile.Close()
+
+    var output bytes.Buffer
+
+    fmt.Fprintln(&output, "// GENERATED BY gitlab.codemonkeysoftware.net/b/hatmill/internal/elementgen")
+    fmt.Fprintln(&output, "// DO NOT EDIT!\n")
+    fmt.Fprintln(&output, "package ", packageName, "\n")
+
+    scanner := bufio.NewScanner(inputFile)
+    for scanner.Scan() {
+        line := scanner.Text()
+        if line == "" {
+            continue
+        }
+
+        var tagName, elemType string
+        _, err = fmt.Sscanf(line, "%s %s", &tagName, &elemType)
+        if err != nil {
+            log.Fatalf("error parsing input line: %s", err)
+        }
+
+        var template string
+        switch elemType {
+        case parentType:
+            template = parentTemplate
+        case emptyType:
+            template = emptyTemplate
+        default:
+            log.Fatal("unknown element type: ", elemType)
+        }
+        fmt.Fprintf(&output, template, strings.Title(tagName), tagName)
+    }
+    if err := scanner.Err(); err != nil {
+        log.Fatalf("error scanning input: %s", err)
+    }
+
+    formatted, err := format.Source(output.Bytes())
+    if err != nil {
+        log.Fatalf("error formatting output: %s", err)
+    }
+
+    err = ioutil.WriteFile(outputPath, formatted, 0644)
+    if err != nil {
+        log.Fatalf("error writing output: %s", err)
+    }
+}