restructure dir, create makefile

1 files changed, 185 insertions, 0 deletions

diff --git a/redes/lexparse.c b/redes/lexparse.c
new file mode 100644
index 0000000..0ea86df
--- /dev/null
+++ b/redes/lexparse.c
@@ -0,0 +1,185 @@
+#include <ctype.h>
+#include "syntax.h"
+#include "utils.h"
+
+typedef struct {
+    Word word_germ;
+    String lit_germ;
+} LexingBuffer;
+
+typedef struct {
+    TokenVec* token_pool;
+    TokenPtrVec* top_tokens;
+} PseudoAst;
+
+static void consolidate_buffer(LexingBuffer* buf, PseudoAst ps_ast) {
+    if (buf->lit_germ.count > 0) {
+        push_to_Word(&buf->word_germ, (Chunk){
+            .qmode = UN_Q,
+            .kind = CHUNK_LIT,
+            .as.lit_str = inner(&buf->lit_germ)
+        });
+        buf->lit_germ = make_String(256);
+    }
+    if (buf->word_germ.count > 0) {
+        Token* tok_ptr = push_to_TokenVec(ps_ast.token_pool, (Token){
+            .kind = TOK_WORD,
+            .as.word = buf->word_germ
+        });
+        push_to_TokenPtrVec(ps_ast.top_tokens, tok_ptr);
+    }
+}
+
+
+static Chunk collect_un_q_literal(char* line, size_t* pos) {
+    String buf = make_String(256);
+    size_t i;
+    for (i = *pos; line[*pos] != '$' && line[*pos] != '\0' && line[*pos] == ' '; i++) {
+        push_to_String(&buf, line[*pos]);
+    }
+    *pos = i;
+    return (Chunk){
+        .qmode = UN_Q,
+        .kind = CHUNK_LIT,
+        .as.lit_str = inner(&buf),
+    };
+}
+
+
+static Chunk collect_single_q_section(char* line, size_t* pos) {
+    (*pos)++;
+    String buf = make_String(256);
+    size_t i;
+    for (i = *pos; line[*pos] != '\'' && line[*pos] != '\0'; i++) {
+        push_to_String(&buf, line[*pos]);
+    }
+    if (line[i] == '\0') exit(44);
+
+    *pos = ++i;
+    return (Chunk){
+        .qmode = SINGLE_Q,
+        .kind = CHUNK_LIT,
+        .as.lit_str = inner(&buf)
+    };
+}
+
+static Chunk collect_double_q_section(char* line, size_t* pos) {
+    // TODO: add the extra double-q expansions
+    (*pos)++;
+    String buf = make_String(256);
+    size_t i;
+    for (i = *pos; line[*pos] != '\'' && line[*pos] != '\0'; i++) {
+        push_to_String(&buf, line[*pos]);
+    }
+    if (line[i] == '\0') exit(44);
+
+    *pos = ++i;
+    return (Chunk){
+        .qmode = DOUBLE_Q,
+        .kind = CHUNK_LIT,
+        .as.lit_str = inner(&buf)
+    };
+}
+
+DECLARE_MAYBE(SpecialToken, MaybeSpecialToken)
+
+
+static MaybeSpecialToken recognize_spec_token(char* line, size_t* pos) {
+    // TODO: add more error guards for peekaheads
+    char next_ch;
+
+    switch (line[*pos]) {
+        case '|':
+            (*pos)++;
+            return (MaybeSpecialToken){.some = true, .value = SPEC_PIPE};
+        case '>':
+            next_ch = line[(*pos)+1];
+            switch (next_ch) {
+                case '(':
+                    return (MaybeSpecialToken){.some = false};
+                case '>':
+                    *pos += 2;
+                    return (MaybeSpecialToken){.some = true, .value = SPEC_REDIR_W_APPEND};
+                default:
+                    (*pos)++;
+                    return (MaybeSpecialToken){.some = true, .value = SPEC_REDIR_W_TRUNC};
+            }
+        case '<':
+            next_ch = line[(*pos)+1];
+            if (line[(*pos)+1] == '(') {
+                return (MaybeSpecialToken){.some = false};
+            } else {
+                (*pos)++;
+                return (MaybeSpecialToken){.some = true, .value = SPEC_REDIR_R};
+            }
+        default:
+            return (MaybeSpecialToken){.some = false};
+    }
+}
+
+static void lex_level(char* line, size_t* pos, char until, PseudoAst ps_ast) {
+    LexingBuffer buf = {.word_germ = make_Word(256), .lit_germ = make_String(256)};
+    while (line[*pos] != until) {
+        if (line[*pos] == ' ') {
+            consolidate_buffer(&buf, ps_ast);
+            while (line[*pos] == ' ') (*pos)++;
+            continue;
+        }
+        MaybeSpecialToken m_spec = recognize_spec_token(line, pos);
+        if (m_spec.some) {
+            Token* tok_ptr = push_to_TokenVec(ps_ast.token_pool, (Token){
+                .kind = TOK_SPEC, 
+                .as.spec = m_spec.value
+            });
+            push_to_TokenPtrVec(ps_ast.top_tokens, tok_ptr);
+            continue;
+        }
+
+        if (line[*pos] == '\'') {
+            Chunk chunk = collect_single_q_section(line, pos);
+            push_to_Word(&buf.word_germ, chunk);
+        } else if (line[*pos] == '\"') {
+            Chunk chunk = collect_double_q_section(line, pos);
+            push_to_Word(&buf.word_germ, chunk);
+        } else if (line[*pos] == '<' && line[(*pos)+1] == '(') {
+            *pos += 2;
+            consolidate_buffer(&buf, ps_ast);
+            TokenPtrVec procsub_toks = make_TokenPtrVec(256);
+            lex_level(line, pos, ')', (PseudoAst){
+                .token_pool = ps_ast.token_pool,
+                .top_tokens = &procsub_toks
+            });
+            (*pos)++;   // consume ')'
+            Token* tok_ptr = push_to_TokenVec(ps_ast.token_pool, (Token){
+                .kind = TOK_SUB_IN,
+                .as.procsub_toks = procsub_toks,
+            });
+            push_to_TokenPtrVec(ps_ast.top_tokens, tok_ptr);
+        } else if (line[*pos] == '>' && line[(*pos)+1] == '(') {
+            *pos += 2;
+            consolidate_buffer(&buf, ps_ast);
+            TokenPtrVec procsub_toks = make_TokenPtrVec(256);
+            lex_level(line, pos, ')', (PseudoAst){
+                .token_pool = ps_ast.token_pool,
+                .top_tokens = &procsub_toks
+            });
+            (*pos)++;   // consume ')'
+            Token* tok_ptr = push_to_TokenVec(ps_ast.token_pool, (Token){
+                .kind = TOK_SUB_OUT,
+                .as.procsub_toks = procsub_toks,
+            });
+            push_to_TokenPtrVec(ps_ast.top_tokens, tok_ptr);
+        }
+    }
+}
+
+Ast lex(char* input) {
+    size_t line_pos = 0;
+    TokenVec token_pool = make_TokenVec(256);
+    TokenPtrVec top_tokens = make_TokenPtrVec(256);
+    lex_level(input, &line_pos, '\0', (PseudoAst){
+        .token_pool = &token_pool, 
+        .top_tokens = &top_tokens
+    });
+    return (Ast){.token_pool = token_pool, .top_tokens = top_tokens};
+}