view tests/test-issue522.t @ 25596:c1975809a6b5

templater: take any string literals as template, but not for rawstring (BC)

This patch series is intended to unify the interpretation of string literals.
It is breaking change that boldly assumes

 a. string literal "..." never contains template-like fragment or it is
    intended to be a template
 b. we tend to use raw string literal r"..." for regexp pattern in which "{"
    should have different meaning

Currently, we don't have a comprehensible rule how string literals are
evaluated in template functions. For example, fill() takes "initialindent"
and "hangindent" as templates, but not for "text", whereas "text" is a
template in pad() function.

  date(date, fmt)
  diff(includepattern, excludepattern)
  fill(text, width, initialident: T, hangindent: T)
  get(dict, key)
  if(expr, then: T, else: T)
  ifcontains(search, thing, then: T, else: T)
  ifeq(expr1, expr2, then: T, else: T)
  indent(text, indentchars, firstline)
  join(list, sep)
  label(label: T, expr: T)
  pad(text: T, width, fillchar, right)
  revset(query, formatargs...])
  rstdoc(text, style)
  shortest(node, minlength)
  startswith(pattern, text)
  strip(text, chars)
  sub(pattern, replacement, expression: T)
  word(number, text, separator)
  expr % template: T

  T: interpret "string" or r"rawstring" as template

This patch series adjusts the rule as follows:

 a. string literal, '' or "", starts template processing (BC)
 b. raw string literal, r'' or r"", disables both \-escape and template
    processing (BC, done by subsequent patches)
 c. fragment not surrounded by {} is non-templated string

  "ccc{'aaa'}{r'bbb'}"
   ------------------  *: template
   ---                 c: string
        ---            a: template
                ---    b: rawstring

Because this can eliminate the compilation of template arguments from the
evaluation phase, "hg log -Tdefault" gets faster.

  % cd mozilla-central
  % LANG=C HGRCPATH=/dev/null hg log -Tdefault -r0:10000 --time > /dev/null
  before: real 4.870 secs (user 4.860+0.000 sys 0.010+0.000)
  after:  real 3.480 secs (user 3.440+0.000 sys 0.030+0.000)

Also, this will allow us to parse nested templates at once for better error
indication.

http://mercurial.selenic.com/bts/issue522

In the merge below, the file "foo" has the same contents in both
parents, but if we look at the file-level history, we'll notice that
the version in p1 is an ancestor of the version in p2. This test makes
sure that we'll use the version from p2 in the manifest of the merge
revision.

  $ hg init

  $ echo foo > foo
  $ hg ci -qAm 'add foo'

  $ echo bar >> foo
  $ hg ci -m 'change foo'

  $ hg backout -r tip -m 'backout changed foo'
  reverting foo
  changeset 2:4d9e78aaceee backs out changeset 1:b515023e500e

  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ touch bar
  $ hg ci -qAm 'add bar'

  $ hg merge --debug
    searching for copies back to rev 1
    unmatched files in local:
     bar
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: bbd179dfa0a7, local: 71766447bdbb+, remote: 4d9e78aaceee
   foo: remote is newer -> g
  getting foo
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg debugstate | grep foo
  m   0         -2 unset               foo

  $ hg st -A foo
  M foo

  $ hg ci -m 'merge'

  $ hg manifest --debug | grep foo
  c6fc755d7e68f49f880599da29f15add41f42f5a 644   foo

  $ hg debugindex foo
     rev    offset  length  ..... linkrev nodeid       p1           p2 (re)
       0         0       5  .....       0 2ed2a3912a0b 000000000000 000000000000 (re)
       1         5       9  .....       1 6f4310b00b9a 2ed2a3912a0b 000000000000 (re)
       2        14       5  .....       2 c6fc755d7e68 6f4310b00b9a 000000000000 (re)