templater: introduce word function
This function allows returning only the nth "word" from a string. By default
a string is split as by Python's split() function default, but an optional
third parameter can also override what string the string is split by.
--- a/mercurial/help/templates.txt Thu Jul 03 23:01:37 2014 -0500
+++ b/mercurial/help/templates.txt Thu Jun 12 18:02:23 2014 -0700
@@ -72,6 +72,8 @@
- sub(pat, repl, expr)
+- word(number, text[, separator])
+
Also, for any expression that returns a list, there is a list operator:
- expr % "{template}"
@@ -130,3 +132,7 @@
- Show only commit descriptions that start with "template"::
$ hg log --template "{startswith(\"template\", firstline(desc))}\n"
+
+- Print the first word of each line of a commit message::
+
+ $ hg log --template "{word(\"0\", desc)}\n"
--- a/mercurial/templater.py Thu Jul 03 23:01:37 2014 -0500
+++ b/mercurial/templater.py Thu Jun 12 18:02:23 2014 -0700
@@ -477,6 +477,25 @@
return ''
+def word(context, mapping, args):
+ """return nth word from a string"""
+ if not (2 <= len(args) <= 3):
+ raise error.ParseError(_("word expects two or three arguments, got %d")
+ % len(args))
+
+ num = int(stringify(args[0][0](context, mapping, args[0][1])))
+ text = stringify(args[1][0](context, mapping, args[1][1]))
+ if len(args) == 3:
+ splitter = stringify(args[2][0](context, mapping, args[2][1]))
+ else:
+ splitter = None
+
+ tokens = text.split(splitter)
+ if num >= len(tokens):
+ return ''
+ else:
+ return tokens[num]
+
methods = {
"string": lambda e, c: (runstring, e[1]),
"rawstring": lambda e, c: (runrawstring, e[1]),
@@ -504,6 +523,7 @@
"startswith": startswith,
"strip": strip,
"sub": sub,
+ "word": word,
}
# template engine
--- a/tests/test-command-template.t Thu Jul 03 23:01:37 2014 -0500
+++ b/tests/test-command-template.t Thu Jun 12 18:02:23 2014 -0700
@@ -1917,3 +1917,61 @@
$ hg log -Gv -R a --template '{desc|user()}'
hg: parse error: expected a symbol, got 'func'
[255]
+
+Test word function (including index out of bounds graceful failure)
+
+ $ hg log -Gv -R a --template "{word('1', desc)}"
+ @
+ |
+ o
+ |
+ o
+
+ o
+ |\
+ | o head
+ | |
+ o | branch
+ |/
+ o user,
+ |
+ o person
+ |
+ o 1
+ |
+ o 1
+
+
+Test word third parameter used as splitter
+
+ $ hg log -Gv -R a --template "{word('0', desc, 'o')}"
+ @ future
+ |
+ o third
+ |
+ o sec
+
+ o merge
+ |\
+ | o new head
+ | |
+ o | new branch
+ |/
+ o n
+ |
+ o n
+ |
+ o
+ |
+ o line 1
+ line 2
+
+Test word error messages for not enough and too many arguments
+
+ $ hg log -Gv -R a --template "{word('0')}"
+ hg: parse error: word expects two or three arguments, got 1
+ [255]
+
+ $ hg log -Gv -R a --template "{word('0', desc, 'o', 'h', 'b', 'o', 'y')}"
+ hg: parse error: word expects two or three arguments, got 7
+ [255]