pebblisp/src/tokens.c

152 lines
3.8 KiB
C

#include "tokens.h"
#include <stdlib.h>
#include <string.h>
#ifdef STANDALONE
#include <stdio.h>
#undef printd
#define printd(...) fprintf(stderr, __VA_ARGS__)
#else
#include <pebble.h>
#undef printd
#undef printf
#define printf(...) APP_LOG(APP_LOG_LEVEL_DEBUG, __VA_ARGS__)
#define printd(...) printf(__VA_ARGS__)
#endif
#define ERR_LEN 256
/*
* Grammar:
* token
* expr
* (op expr expr)
* (list expr expr ... )
*/
// Is the char a standalone token?
static const char singleTokens[] = "()+-*/='";
int isSingle(const char c) {
int i = 0;
while(singleTokens[i] != '\0'){
if(singleTokens[i] == c)
return singleTokens[i];
i++;
}
return 0;
}
int isDigit(const char c) {
return c >= '0' && c <= '9';
}
int isHex(const char c) {
return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f');
}
int isWhitespace(const char c) {
return c == ' ' || c == '\t' || c == '\n';
}
int notWhitespace(const char c) {
return !isWhitespace(c);
}
// Return needs to be freed, if not null
struct Slice *nf_tokenize(const char *input, struct Error *err)
{
if(!input) {
err->context = malloc(sizeof(char) * ERR_LEN);
strcpy(err->context, "no input");
return NULL;
}
int token_count = MAX_TOK_CNT;
struct Slice *slices = malloc(sizeof(struct Slice) * token_count);
while(slices == NULL) {
token_count /= 2;
slices = malloc(sizeof(struct Slice) * token_count);
}
int i = 0;
int slice = 0;
int parens = 0;
while(input[i] != '\0') {
int l = 1;
// printd("input: '%c'\n", input[i]);
if(isWhitespace(input[i]) || input[i] == ';') {
i++;
continue;
}
if(input[i] == '(') {
parens++;
} else if (input[i] == ')') {
parens--;
if(parens < 0) {
err->context = malloc(sizeof(char) * ERR_LEN + 1);
err->code = MISMATCHED_PARENS;
int start = i > ERR_LEN ? i - ERR_LEN : 0;
strncpy(err->context, &input[start], ERR_LEN);
free(slices);
return NULL;
}
}
slices[slice].text = &input[i];
if(isSingle(input[i])) {
i++;
} else if(input[i] == '"') {
if(input[i + 1] == '"' && input [i + 2] == '"') {
// Triple-quoted block
i += 2;
slices[slice].text += 2;
for(;;) {
i++;
if(input[i] == '"' && input[i + 1] == '"' && input[i + 2] == '"') {
break;
}
if(input[i] == '\0' || input[i + 1] == '\0' || input[i + 2] == '\0') {
err->context = malloc(sizeof(char) * ERR_LEN + 1);
err->code = UNEXPECTED_EOF;
int start = i > ERR_LEN ? i - ERR_LEN : 0;
strncpy(err->context, &input[start], ERR_LEN);
free(slices);
return NULL;
}
}
} else {
// Simple string
while(input[++i] != '"' && input[i] != '\0') {
l++;
}
}
i++;
} else {
while(!isWhitespace(input[++i]) && !isSingle(input[i]) && input[i] != '\0') {
l++;
}
}
slices[slice].length = l;
slice++;
}
if(parens != 0){
err->context = malloc(sizeof(char) * ERR_LEN);
err->code = MISMATCHED_PARENS;
int start = i > ERR_LEN ? i - ERR_LEN : 0;
strncpy(err->context, &input[start], ERR_LEN);
free(slices);
return NULL;
}
slices[slice].text = NULL;
slices[slice].length = 0;
return slices;
}