diff options
Diffstat (limited to 'src/prelexer.c')
| -rw-r--r-- | src/prelexer.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/src/prelexer.c b/src/prelexer.c new file mode 100644 index 0000000..225d499 --- /dev/null +++ b/src/prelexer.c @@ -0,0 +1,214 @@ +#include <stdlib.h> +#include <string.h> +#include <glib.h> +#include <assert.h> + +#include "prelexer.h" + +/* Creates a scanner state which will be useful for accessing the lexer later. */ +PreLexerState* +pl_create_scanner(const gchar* input) +{ + PreLexerState* state; + assert(input != NULL); + assert(g_utf8_validate(input, -1, NULL)); + state = (PreLexerState *) malloc(sizeof(PreLexerState)); + assert(state != NULL); + state->stream = g_strdup(input); + state->length = strlen(state->stream); /* Can't find a GLib replacement of strlen. The mailing list discussion says, it is not implemented because strlen is perfectly capable. :) */ + state->next_index = 0; + state->mark_index = 0; + return state; +} + +/* Destroy and free memory used by LexerState object. */ +void +pl_destroy_scanner(PreLexerState* state) +{ + free(state->stream); + free(state); +} + +/* Roll back last scanned unichar. */ +void +pl_roll_back(PreLexerState* state) +{ + gchar* tmp; + tmp = g_utf8_find_prev_char(state->stream, state->stream + state->next_index); + if(tmp == NULL) + /* Already at the beginning of the stram. Reset index. */ + state->next_index = 0; + else + state->next_index = tmp - state->stream; +} + +/* Get validated gunichar from input stream. */ +gunichar +pl_get_next_gunichar(PreLexerState* state) +{ + gunichar ret; + if(state->next_index >= state->length) + { + /* To prevent scanning last letter multiple times, when a single unconditional rollback is used. */ + if(state->next_index == state->length) + state->next_index++; + return 0; + } + ret = g_utf8_get_char_validated(state->stream + state->next_index, -1); + state->next_index = g_utf8_next_char(state->stream + state->next_index) - state->stream; + return ret; +} + +/* Set marker index. To be used for highlighting and error reporting. */ +void +pl_set_marker(PreLexerState* state) +{ + state->mark_index = state->next_index; +} + +/* Get marked substring. To be used for error reporting. */ +gchar* +pl_get_marked_substring(const PreLexerState* state) +{ + return g_strndup(state->stream + state->mark_index, state->next_index - state->mark_index); +} + +/* Compares a list of strings with given unichar. To be used by pl_get_next_token() only. */ +static gboolean +pl_compare_all(const gunichar ch, const gint count, gchar *arr[]) +{ + gint l; + for(l = 0; l < count; l++) + { + if(ch == g_utf8_get_char_validated(arr[l], -1)) + return TRUE; + } + return FALSE; +} + +/* Pre-Lexer tokanizer. To be called only by Lexer. */ +LexerTokenType +pl_get_next_token(PreLexerState* state) +{ + gunichar ch = pl_get_next_gunichar(state); + if(pl_compare_all(ch, 2, (gchar*[]){",","."})) + return PL_DECIMAL; + + if(g_unichar_isdigit(ch) || pl_compare_all(ch, 10, (gchar*[]){"〇","〡","〢","〣","〤","〥","〦","〧","〨","〩"})) + return PL_DIGIT; /* 0-9 */ + + if(g_unichar_isxdigit(ch)) + return PL_HEX; /* This is supposed to report just the A-F. */ + + if(pl_compare_all(ch, 10, (gchar*[]){"⁰","¹","²","³","⁴","⁵","⁶","⁷","⁸","⁹"})) + return PL_SUPER_DIGIT; + + if(pl_compare_all(ch, 1, (gchar*[]){"⁻"})) + return PL_SUPER_MINUS; + + if(pl_compare_all(ch, 10, (gchar*[]){"₀","₁","₂","₃","₄","₅","₆","₇","₈","₉"})) + return PL_SUB_DIGIT; + + if(pl_compare_all(ch, 15, (gchar*[]){"½","⅓","⅔","¼","¾","⅕","⅖","⅗","⅘","⅙","⅚","⅛","⅜","⅝","⅞"})) + return PL_FRACTION; + + if(pl_compare_all(ch, 1, (gchar*[]){"°"})) + return PL_DEGREE; + + if(pl_compare_all(ch, 1, (gchar*[]){"'"})) + return PL_MINUTE; + + if(pl_compare_all(ch, 1, (gchar*[]){"\""})) + return PL_SECOND; + + if(g_unichar_isalpha(ch)) + return PL_LETTER; /* All alphabets excluding A-F. [a-fA-F] are reported as PL_HEX. */ + + if(pl_compare_all(ch, 1, (gchar*[]){"∧"})) + return T_AND; + + if(pl_compare_all(ch, 1, (gchar*[]){"∨"})) + return T_OR; + + if(pl_compare_all(ch, 2, (gchar*[]){"⊻","⊕"})) + return T_XOR; + + if(pl_compare_all(ch, 2, (gchar*[]){"¬","~"})) + return T_NOT; + + if(pl_compare_all(ch, 1, (gchar*[]){"+"})) + return T_ADD; + + if(pl_compare_all(ch, 3, (gchar*[]){"-","−","–"})) + return T_SUBTRACT; + + if(pl_compare_all(ch, 2, (gchar*[]){"*","×"})) + return T_MULTIPLY; + + if(pl_compare_all(ch, 3, (gchar*[]){"/","∕","÷"})) + return T_DIV; + + if(pl_compare_all(ch, 1, (gchar*[]){"⌊"})) + return T_L_FLOOR; + + if(pl_compare_all(ch, 1, (gchar*[]){"⌋"})) + return T_R_FLOOR; + + if(pl_compare_all(ch, 1, (gchar*[]){"⌈"})) + return T_L_CEILING; + + if(pl_compare_all(ch, 1, (gchar*[]){"⌉"})) + return T_R_CEILING; + + if(pl_compare_all(ch, 1, (gchar*[]){"√"})) + return T_ROOT; + + if(pl_compare_all(ch, 1, (gchar*[]){"∛"})) + return T_ROOT_3; + + if(pl_compare_all(ch, 1, (gchar*[]){"∜"})) + return T_ROOT_4; + + if(pl_compare_all(ch, 1, (gchar*[]){"="})) + return T_ASSIGN; + + if(pl_compare_all(ch, 1, (gchar*[]){"("})) + return T_L_R_BRACKET; + + if(pl_compare_all(ch, 1, (gchar*[]){")"})) + return T_R_R_BRACKET; + + if(pl_compare_all(ch, 1, (gchar*[]){"["})) + return T_L_S_BRACKET; + + if(pl_compare_all(ch, 1, (gchar*[]){"]"})) + return T_R_S_BRACKET; + + if(pl_compare_all(ch, 1, (gchar*[]){"{"})) + return T_L_C_BRACKET; + + if(pl_compare_all(ch, 1, (gchar*[]){"}"})) + return T_R_C_BRACKET; + + if(pl_compare_all(ch, 1, (gchar*[]){"|"})) + return T_ABS; + + if(pl_compare_all(ch, 1, (gchar*[]){"^"})) + return T_POWER; + + if(pl_compare_all(ch, 1, (gchar*[]){"!"})) + return T_FACTORIAL; + + if(pl_compare_all(ch, 1, (gchar*[]){"%"})) + return T_PERCENTAGE; + + if(pl_compare_all(ch, 4, (gchar*[]){" ","\r","\t","\n"})) + /* Gotta ignore'Em all!!! ;) */ + return PL_SKIP; + + if(ch == 0) + return PL_EOS; + + /* There is no spoon. */ + return T_UNKNOWN; +} |