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Diffstat (limited to 'ide/sentence.ml')
-rw-r--r-- | ide/sentence.ml | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/ide/sentence.ml b/ide/sentence.ml new file mode 100644 index 00000000..dd6b10a4 --- /dev/null +++ b/ide/sentence.ml @@ -0,0 +1,126 @@ +(************************************************************************) +(* v * The Coq Proof Assistant / The Coq Development Team *) +(* <O___,, * INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2015 *) +(* \VV/ **************************************************************) +(* // * This file is distributed under the terms of the *) +(* * GNU Lesser General Public License Version 2.1 *) +(************************************************************************) + +(** {1 Sentences in coqide buffers } *) + +(** Cut a part of the buffer in sentences and tag them. + Invariant: either this slice ends the buffer, or it ends with ".". + May raise [Coq_lex.Unterminated] when the zone ends with + an unterminated sentence. *) + +let split_slice_lax (buffer:GText.buffer) start stop = + buffer#remove_tag ~start ~stop Tags.Script.sentence; + buffer#remove_tag ~start ~stop Tags.Script.error; + buffer#remove_tag ~start ~stop Tags.Script.error_bg; + let slice = buffer#get_text ~start ~stop () in + let apply_tag off tag = + (* off is now a utf8-compliant char offset, cf Coq_lex.utf8_adjust *) + let iter = start#forward_chars off in + buffer#apply_tag ~start:iter ~stop:iter#forward_char tag + in + Coq_lex.delimit_sentences apply_tag slice + +(** Searching forward and backward a position fulfilling some condition *) + +let rec forward_search cond (iter:GText.iter) = + if iter#is_end || cond iter then iter + else forward_search cond iter#forward_char + +let rec backward_search cond (iter:GText.iter) = + if iter#is_start || cond iter then iter + else backward_search cond iter#backward_char + +let is_sentence_end s = + s#has_tag Tags.Script.sentence + +let is_char s c = s#char = Char.code c + +(** Search backward the first character of a sentence, starting at [iter] + and going at most up to [soi] (meant to be the end of the locked zone). + Raise [StartError] when no proper sentence start has been found. + A character following a ending "." is considered as a sentence start + only if this character is a blank. In particular, when a final "." + at the end of the locked zone isn't followed by a blank, then this + non-blank character will be signaled as erroneous in [tag_on_insert] below. +*) + +exception StartError + +let grab_sentence_start (iter:GText.iter) soi = + let cond iter = + if iter#compare soi < 0 then raise StartError; + let prev = iter#backward_char in + is_sentence_end prev && + (not (is_char prev '.') || + List.exists (is_char iter) [' ';'\n';'\r';'\t']) + in + backward_search cond iter + +(** Search forward the first character immediately after a sentence end *) + +let rec grab_sentence_stop (start:GText.iter) = + (forward_search is_sentence_end start)#forward_char + +(** Search forward the first character immediately after a "." sentence end + (and not just a "\{" or "\}" or comment end *) + +let rec grab_ending_dot (start:GText.iter) = + let is_ending_dot s = is_sentence_end s && s#char = Char.code '.' in + (forward_search is_ending_dot start)#forward_char + +(** Retag a zone that has been edited *) + +let tag_on_insert buffer = + (* the start of the non-locked zone *) + let soi = buffer#get_iter_at_mark (`NAME "start_of_input") in + (* the inserted zone is between [prev_insert] and [insert] *) + let insert = buffer#get_iter_at_mark `INSERT in + let prev = buffer#get_iter_at_mark (`NAME "prev_insert") in + (* [prev] is normally always before [insert] even when deleting. + Let's check this nonetheless *) + let prev, insert = + if insert#compare prev < 0 then insert, prev else prev, insert + in + try + let start = grab_sentence_start prev soi in + (** The status of "{" "}" as sentence delimiters is too fragile. + We retag up to the next "." instead. *) + let stop = grab_ending_dot insert in + try split_slice_lax buffer start#backward_char stop + with Coq_lex.Unterminated -> + (* This shouldn't happen frequently. Either: + - we are at eof, with indeed an unfinished sentence. + - we have just inserted an opening of comment or string. + - the inserted text ends with a "." that interacts with the "." + found by [grab_ending_dot] to form a non-ending "..". + In any case, we retag up to eof, since this isn't that costly. *) + if not stop#is_end then + let eoi = buffer#get_iter_at_mark (`NAME "stop_of_input") in + try split_slice_lax buffer start eoi + with Coq_lex.Unterminated -> () + with StartError -> + buffer#apply_tag ~start:soi ~stop:soi#forward_char Tags.Script.error + +let tag_all buffer = + let soi = buffer#get_iter_at_mark (`NAME "start_of_input") in + let eoi = buffer#get_iter_at_mark (`NAME "stop_of_input") in + try split_slice_lax buffer soi eoi + with Coq_lex.Unterminated -> () + +(** Search a sentence around some position *) + +let find buffer (start:GText.iter) = + let soi = buffer#get_iter_at_mark (`NAME "start_of_input") in + try + let start = grab_sentence_start start soi in + let stop = grab_sentence_stop start in + (* Is this phrase non-empty and complete ? *) + if stop#compare start > 0 && is_sentence_end stop#backward_char + then Some (start,stop) + else None + with StartError -> None |