Refactored doc generation, add fi fileIndex alias

pkg/yqlib/doc/File Operators.md

@@ -1,9 +1,11 @@
 File operators are most often used with merge when needing to merge specific files together. Note that when doing this, you will need to use `eval-all` to ensure all yaml documents are loaded into memory before performing the merge (as opposed to `eval` which runs the expression once per document).
 
+Note that the `fileIndex` operator has a short alias of `fi`.
+
 ## Merging files
 Note the use of eval-all to ensure all documents are loaded into memory.
 ```bash
-yq eval-all 'select(fileIndex == 0) * select(filename == "file2.yaml")' file1.yaml file2.yaml
+yq eval-all 'select(fi == 0) * select(filename == "file2.yaml")' file1.yaml file2.yaml
 ```
 ## Get filename
 Given a sample.yml file of:
@@ -33,3 +35,17 @@ will output
 0
 ```
 
+## Get file index alias
+Given a sample.yml file of:
+```yaml
+a: cat
+```
+then
+```bash
+yq eval 'fi' sample.yml
+```
+will output
+```yaml
+0
+```
+

pkg/yqlib/doc/headers/File Operators.md

@@ -1,7 +1,9 @@
 File operators are most often used with merge when needing to merge specific files together. Note that when doing this, you will need to use `eval-all` to ensure all yaml documents are loaded into memory before performing the merge (as opposed to `eval` which runs the expression once per document).
 
+Note that the `fileIndex` operator has a short alias of `fi`.
+
 ## Merging files
 Note the use of eval-all to ensure all documents are loaded into memory.
 ```bash
-yq eval-all 'select(fileIndex == 0) * select(filename == "file2.yaml")' file1.yaml file2.yaml
+yq eval-all 'select(fi == 0) * select(filename == "file2.yaml")' file1.yaml file2.yaml
 ```

pkg/yqlib/operator_file_test.go

@@ -21,6 +21,14 @@ var fileOperatorScenarios = []expressionScenario{
 			"D0, P[], (!!int)::0\n",
 		},
 	},
+	{
+		description: "Get file index alias",
+		document:    `{a: cat}`,
+		expression:  `fi`,
+		expected: []string{
+			"D0, P[], (!!int)::0\n",
+		},
+	},
 }
 
 func TestFileOperatorsScenarios(t *testing.T) {

pkg/yqlib/operators_test.go

@@ -137,13 +137,28 @@ func documentScenarios(t *testing.T, title string, scenarios []expressionScenari
 
 	for _, s := range scenarios {
 		if !s.skipDoc {
+			documentScenario(t, w, s)
+		}
+	}
+	w.Flush()
+}
 
+func documentScenario(t *testing.T, w *bufio.Writer, s expressionScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
 		writeOrPanic(w, s.subdescription)
 		writeOrPanic(w, "\n\n")
 	}
+
+	formattedDoc, formattedDoc2 := documentInput(w, s)
+
+	writeOrPanic(w, "will output\n")
+
+	documentOutput(t, w, s, formattedDoc, formattedDoc2)
+}
+
+func documentInput(w *bufio.Writer, s expressionScenario) (string, string) {
 	formattedDoc := ""
 	formattedDoc2 := ""
 	command := "eval"
@@ -182,9 +197,10 @@ func documentScenarios(t *testing.T, title string, scenarios []expressionScenari
 		writeOrPanic(w, "Running\n")
 		writeOrPanic(w, fmt.Sprintf("```bash\nyq %v --null-input '%v'\n```\n", command, s.expression))
 	}
+	return formattedDoc, formattedDoc2
+}
 
-			writeOrPanic(w, "will output\n")
-
+func documentOutput(t *testing.T, w *bufio.Writer, s expressionScenario, formattedDoc string, formattedDoc2 string) {
 	var output bytes.Buffer
 	var err error
 	printer := NewPrinter(bufio.NewWriter(&output), false, true, false, 2, true)
@@ -233,9 +249,4 @@ func documentScenarios(t *testing.T, title string, scenarios []expressionScenari
 	}
 
 	writeOrPanic(w, fmt.Sprintf("```yaml\n%v```\n\n", output.String()))
-
-		}
-
-	}
-	w.Flush()
 }

pkg/yqlib/path_tokeniser.go

@@ -200,6 +200,7 @@ func initLexer() (*lex.Lexer, error) {
 	lexer.Add([]byte(`alias`), opAssignableToken(GetAlias, AssignAlias))
 	lexer.Add([]byte(`filename`), opToken(GetFilename))
 	lexer.Add([]byte(`fileIndex`), opToken(GetFileIndex))
+	lexer.Add([]byte(`fi`), opToken(GetFileIndex))
 	lexer.Add([]byte(`path`), opToken(GetPath))
 
 	lexer.Add([]byte(`lineComment`), opTokenWithPrefs(GetComment, AssignComment, &CommentOpPreferences{LineComment: true}))