close #2387: record the line numbers for inline code expressions when parsing the document, and show specific line numbers of an inline expression when it throws an error

Author: yihui

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: knitr
 Type: Package
 Title: A General-Purpose Package for Dynamic Report Generation in R
-Version: 1.49.4
+Version: 1.49.5
 Authors@R: c(
     person("Yihui", "Xie", role = c("aut", "cre"), email = "xie@yihui.name", comment = c(ORCID = "0000-0003-0645-5666", URL = "https://yihui.org")),
     person("Abhraneel", "Sarma", role = "ctb"),

NEWS.md

@@ -1,5 +1,9 @@
 # CHANGES IN knitr VERSION 1.50
 
+## NEW FEATURES
+
+- For inline code expressions, their specific line numbers will be shown in the message when errors occur (thanks, @kevinushey, #2387). Previously, the numbers were not specific to the inline code but the lines of the whole text chunk containing the inline code, which are often quite vague.
+
 ## MINOR CHANGES
 
 - Moved implementations of `combine_words()` and `write_bib()` to the **xfun** package as `xfun::join_words()` and `xfun::pkg_bib()`, respectively, since they are not directly relevant to **knitr**. The functions `combine_words()` and `write_bib()` are still kept in **knitr**, and can continue to be used in the future.

R/block.R

@@ -568,9 +568,11 @@ inline_exec = function(
   code = block$code; input = block$input
   if ((n <- length(code)) == 0) return(input) # untouched if no code is found
   code.src = block$code.src
+  lines = block$lines
 
   ans = character(n)
   for (i in 1:n) {
+    knit_concord$set(offset = lines[i, ])
     tryCatch(parse_only(code[i]), error = function(e) {
       stop2('Failed to parse the inline R code: ', code.src[i], '\nReason: ', e$message)
     })

R/concordance.R

@@ -2,7 +2,7 @@
 
 # record input/output lines numbers in Rnw/tex and filenames
 knit_concord = new_defaults(list(
-  inlines = NULL, outlines = NULL, infile = NULL, outfile = NULL, block = NULL
+  inlines = NULL, outlines = NULL, infile = NULL, outfile = NULL, block = NULL, offset = NULL
 ))
 
 # do not consider child mode for concordance
@@ -13,8 +13,12 @@ concord_mode = function() {
 current_lines = function(i = knit_concord$get('block')) {
   # a helpr function to return line numbers for block i
   n = knit_concord$get('inlines')
-  n1 = sum(head(n, i)); n0 = n1 - n[i] + 2
-  paste(c(min(n0, n1), n1), collapse = '-')
+  n1 = sum(head(n, i)); n0 = min(n1, n1 - n[i] + 1)
+  # adjust line numbers for inline code expressions
+  if (length(o <- knit_concord$get('offset')) == 2) {
+    n1 = n0 + o[2]; n0 = n0 + o[1]
+  }
+  paste(c(n0, n1), collapse = '-')
 }
 
 # generate concordance for RStudio

R/output.R

@@ -323,6 +323,7 @@ process_file = function(text, output) {
       },
       if (labels[i] != '') sprintf(' [%s]', labels[i]), get_loc
     )
+    knit_concord$set(offset = NULL)
   }
 
   if (!tangle) res = insert_header(res)  # insert header

R/parser.R

@@ -232,18 +232,21 @@ parse_inline = function(input, patterns) {
   loc = cbind(start = numeric(0), end = numeric(0))
   if (group_pattern(inline.code)) loc = str_locate(input, inline.code)[[1]]
   code1 = code2 = character()
+  lines = integer()
   if (nrow(loc)) {
     code = t(str_match(input, inline.code))
     if (NCOL(code) >= 2L) {
       code1 = code[, 1L]
       code2 = apply(code[, -1L, drop = FALSE], 1, paste, collapse = '')
+      nl = gregexpr('\n', input, fixed = TRUE)[[1]]
+      lines = if (length(nl) > 1 || nl > -1) findInterval(loc, nl) else c(0L, 0L)
     }
   }
 
-  structure(
-    list(input = input, location = loc, code = code2, code.src = code1),
-    class = 'inline'
-  )
+  structure(list(
+    input = input, location = loc, code = code2, code.src = code1,
+    lines = matrix(lines, ncol = 2)
+  ), class = 'inline')
 }
 
 print_inline = function(x) {