Fold checkNoOverlap and checkNoRepeatedRead into heldCheck, so compileFormat compiles and nothing more

builtins_test.go

@@ -188,12 +188,12 @@ func ibanValid(s string) bool {
 	return rem == 1
 }
 
-// TestRegistryShapes pins the builtin contract compileOps relies on: every entry
+// TestRegistryShapes pins the builtin contract compileFormat relies on: every entry
 // supplies prep, and args parsed at compile only behind a check.
 func TestRegistryShapes(t *testing.T) {
 	for name, b := range builtins {
 		if b.prep == nil {
-			t.Errorf("builtin %q has no prep: compileOps would call a nil func", name)
+			t.Errorf("builtin %q has no prep: compileFormat would call a nil func", name)
 		}
 		if b.arity != 0 && b.checkArgs == nil {
 			t.Errorf("builtin %q parses args in prep with no check", name)
@@ -203,7 +203,7 @@ func TestRegistryShapes(t *testing.T) {
 
 // TestArgGuardsPanic pins the guards that report a builtin arg its check should
 // have rejected. No data reaches them — checkFunc runs a builtin's check before
-// compileOps ever calls prep — so they are exercised directly.
+// compileFormat ever calls prep — so they are exercised directly.
 func TestArgGuardsPanic(t *testing.T) {
 	for name, call := range map[string]func(){
 		"atoi on an unvalidated arg": func() { atoi("nope") },

format.go

@@ -441,19 +441,9 @@ func (c *formatOps) field(tok formatToken, refs map[string]refBinding) {
 	c.ops = append(c.ops, op{formatToken: tok, arms: arms})
 }
 
-// compileFormat compiles a format into ops, and applies the fences that need the
-// compiled reads.
-func compileFormat(toks []formatToken, refs map[string]refBinding) (formatOps, error) {
-	c := compileOps(toks, refs)
-	if err := checkNoOverlap(c); err != nil {
-		return c, err
-	}
-	return c, checkNoRepeatedRead(c)
-}
-
-// compileOps compiles a parsed format. Call checkTokens first: it is what proves
+// compileFormat compiles a parsed format. Call checkTokens first: it is what proves
 // every token valid.
-func compileOps(toks []formatToken, refs map[string]refBinding) formatOps {
+func compileFormat(toks []formatToken, refs map[string]refBinding) formatOps {
 	var c formatOps
 	for _, tok := range toks {
 		switch tok.kind {

holdfence.go

@@ -15,10 +15,23 @@ func heldCheck(path string, n node) error {
 	if !ok || len(t.compiled.held) == 0 {
 		return nil
 	}
+	if err := checkHeld(t); err != nil {
+		return fmt.Errorf("%s: %w", t.site.label(path), err)
+	}
+	return nil
+}
+
+func checkHeld(t *template) error {
+	if err := checkNoOverlap(t.compiled); err != nil {
+		return err
+	}
+	if err := checkNoRepeatedRead(t.compiled); err != nil {
+		return err
+	}
 	readers := pathHeadReaders(t.compiled)
 	for _, name := range heldNames(t) {
 		if err := checkNameHeld(t, name, readers); err != nil {
-			return fmt.Errorf("%s: %w", path, err)
+			return err
 		}
 	}
 	return nil

node.go

@@ -73,6 +73,14 @@ func (s tableSite) isCell() bool {
 	return s.table != nil && s.row != formatRow
 }
 
+// label names the template at path in an error, a cell by its line in the rows file.
+func (s tableSite) label(path string) string {
+	if s.isCell() {
+		return fmt.Sprintf("%s, line %d", path, s.row+2)
+	}
+	return path
+}
+
 // templateLink is what a template resolves to in the assembled tree.
 type templateLink struct {
 	refs         map[string]refBinding // each reference the format reads -> what it resolves to

reference.go

@@ -81,18 +81,11 @@ func linkRefs(root map[string]node) error {
 // linkTemplate resolves t's references in category, "" for an inline template, and
 // compiles its format against them.
 func linkTemplate(folder []string, path, category string, t *template, root map[string]node) error {
-	if t.site.isCell() {
-		path = fmt.Sprintf("%s, line %d", path, t.site.row+2)
-	}
-	link, err := t.resolveLink(folder, path, category, root)
+	link, err := t.resolveLink(folder, t.site.label(path), category, root)
 	if err != nil {
 		return err
 	}
-	compiled, err := compileFormat(t.tokens, link.refs)
-	if err != nil {
-		return fmt.Errorf("%s: %w", path, err)
-	}
-	t.link, t.compiled = link, compiled
+	t.link, t.compiled = link, compileFormat(t.tokens, link.refs)
 	compileArms(t)
 	return nil
 }