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Diffstat (limited to 'src/lexer.c')
| -rw-r--r-- | src/lexer.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/src/lexer.c b/src/lexer.c new file mode 100644 index 0000000..4fbc313 --- /dev/null +++ b/src/lexer.c @@ -0,0 +1,235 @@ +/* + * Copyright (C) 2012-2024 Robin Haberkorn + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <glib.h> + +#include "sciteco.h" +#include "view.h" +#include "parser.h" +#include "lexer.h" + +static teco_style_t +teco_lexer_getstyle(teco_view_t *view, teco_machine_main_t *machine, + gunichar chr) +{ + teco_style_t style = machine->parent.current->style; + + /* + * FIXME: At least this special workaround for numbers might be + * unnecessary once we get a special parser state for parsing numbers. + * + * FIXME: What about ^* and ^/? + * They are currently highlighted as commands. + */ + if (machine->parent.current->keymacro_mask & TECO_KEYMACRO_MASK_START) { + switch (chr) { + case '0'...'9': + style = SCE_SCITECO_NUMBER; + break; + case '+': + case '-': + case '*': + case '/': + case '#': + case '&': + style = SCE_SCITECO_OPERATOR; + break; + } + } + + /* + * FIXME: Perhaps as an optional lexer property, we should support + * styling commands with SCE_SCITECO_DEFAULT or SCE_SCITECO_COMMAND + * in alternating order, so you can discern chains of commands. + */ + if (!teco_machine_input(&machine->parent, chr, NULL)) { + /* + * Probably a syntax error, so the erroneous symbol + * is highlighted and we reset the parser's state machine. + */ + style = SCE_SCITECO_INVALID; + + /* + * FIXME: Perhaps we should simply reset the state to teco_state_start? + */ + gsize macro_pc = machine->macro_pc; + teco_machine_main_clear(machine); + teco_machine_main_init(machine, NULL, FALSE); + machine->mode = TECO_MODE_LEXING; + machine->macro_pc = macro_pc; + } else if (machine->parent.current->style == SCE_SCITECO_LABEL) { + /* don't highlight the leading `!` as SCE_SCITECO_COMMAND */ + style = SCE_SCITECO_LABEL; + } + + return style; +} + +static void +teco_lexer_step(teco_view_t *view, teco_machine_main_t *machine, + teco_machine_main_t *macrodef_machine, + const gchar *macro, gsize start, gsize max_len, + guint *cur_line, guint *cur_col, gint *safe_col) +{ + if (*cur_line == 0 && *cur_col == 0 && *macro == '#') { + /* hash-bang line */ + machine->macro_pc = teco_view_ssm(view, SCI_POSITIONFROMLINE, 1, 0); + teco_view_ssm(view, SCI_STARTSTYLING, 0, 0); + teco_view_ssm(view, SCI_SETSTYLING, machine->macro_pc, SCE_SCITECO_COMMENT); + teco_view_ssm(view, SCI_SETLINESTATE, 0, -1); + (*cur_line)++; + *safe_col = 0; + return; + } + + gsize old_pc = machine->macro_pc; + + teco_style_t style = SCE_SCITECO_DEFAULT; + + gint32 chr = g_utf8_get_char_validated(macro+machine->macro_pc, + max_len-machine->macro_pc); + if (chr < 0) { + /* + * Invalid UTF-8 byte sequence: + * A source file could contain all sorts of data garbage or + * you could manually M[lexer.set.sciteco] on an ANSI-encoded file. + */ + machine->macro_pc++; + style = SCE_SCITECO_INVALID; + } else { + machine->macro_pc = g_utf8_next_char(macro+machine->macro_pc) - macro; + + gunichar escape_char = machine->expectstring.machine.escape_char; + style = teco_lexer_getstyle(view, machine, chr); + + /* + * Optionally style @^Uq{ ... } contents like macro definitions. + * The curly braces will be styled like regular commands. + * + * FIXME: This will not work with nested macro definitions. + * FIXME: This cannot currently be disabled since SCI_SETPROPERTY + * cannot be accessed with ES. + * We could only map it to an ED flag. + */ + if ((escape_char == '{' || machine->expectstring.machine.escape_char == '{') && + teco_view_ssm(view, SCI_GETPROPERTYINT, (uptr_t)"lexer.sciteco.macrodef", TRUE)) + style = teco_lexer_getstyle(view, macrodef_machine, chr); + } + + *cur_col += machine->macro_pc - old_pc; + + teco_view_ssm(view, SCI_STARTSTYLING, start+old_pc, 0); + teco_view_ssm(view, SCI_SETSTYLING, machine->macro_pc-old_pc, style); + + if (chr == '\n') { + /* update line state to the last column with a clean start state */ + teco_view_ssm(view, SCI_SETLINESTATE, *cur_line, *safe_col); + (*cur_line)++; + *cur_col = 0; + *safe_col = -1; /* no clean state by default */ + } + + if (style != SCE_SCITECO_INVALID && + machine->parent.current->keymacro_mask & TECO_KEYMACRO_MASK_START && + !machine->modifier_at) + /* clean parser state */ + *safe_col = *cur_col; +} + +/** + * Style SciTECO source code, i.e. perform syntax highlighting + * for the SciTECO language. + * + * @para view The Scintilla view to operate on. + * @para end The position in bytes where to stop styling. + */ +void +teco_lexer_style(teco_view_t *view, gsize end) +{ + /* should always be TRUE */ + gboolean old_undo_enabled = teco_undo_enabled; + teco_undo_enabled = FALSE; + + gsize start = teco_view_ssm(view, SCI_GETENDSTYLED, 0, 0); + guint start_line = teco_view_ssm(view, SCI_LINEFROMPOSITION, start, 0); + gint start_col = 0; + + /* + * The line state stores the laster character (column) in bytes, + * that starts from a fresh parser state. + * It's -1 if the line does not have a clean parser state. + * Therefore we search for the first line before `start` that has a + * known clean parser state. + */ + if (start_line > 0) { + do + start_line--; + while ((start_col = teco_view_ssm(view, SCI_GETLINESTATE, start_line, 0)) < 0 && + start_line > 0); + start_col = MAX(start_col, 0); + } + start = teco_view_ssm(view, SCI_POSITIONFROMLINE, start_line, 0) + start_col; + g_assert(end > start); + + g_auto(teco_machine_main_t) machine; + teco_machine_main_init(&machine, NULL, FALSE); + machine.mode = TECO_MODE_LEXING; + + /* for lexing the contents of @^Uq{...} */ + g_auto(teco_machine_main_t) macrodef_machine; + teco_machine_main_init(¯odef_machine, NULL, FALSE); + macrodef_machine.mode = TECO_MODE_LEXING; + + g_assert(start_col >= 0); + guint col = start_col; + + /* + * NOTE: We could have also used teco_view_get_character(), + * but this will use much less Scintilla messages without + * removing dot. + */ + const gchar *macro; + sptr_t gap = teco_view_ssm(view, SCI_GETGAPPOSITION, 0, 0); + if (start < gap && gap < end) { + macro = (const gchar *)teco_view_ssm(view, SCI_GETRANGEPOINTER, start, gap); + while (machine.macro_pc < gap-start) + teco_lexer_step(view, &machine, ¯odef_machine, + macro, start, gap-start, + &start_line, &col, &start_col); + /* + * This might have lexed more than gap-start bytes + * (e.g. a hash-bang line) + */ + start += machine.macro_pc; + } + + macro = (const gchar *)teco_view_ssm(view, SCI_GETRANGEPOINTER, start, end-start); + machine.macro_pc = 0; + while (machine.macro_pc < end-start) + teco_lexer_step(view, &machine, ¯odef_machine, + macro, start, end-start, + &start_line, &col, &start_col); + + /* set line state on the very last line */ + teco_view_ssm(view, SCI_SETLINESTATE, start_line, start_col); + + teco_undo_enabled = old_undo_enabled; +} |