FEATURE: Add include as a string functionality.

Includes happy path tests for including a string.

fixes #15

docsite/site/content/reference/grammar.md

@@ -44,9 +44,10 @@ rbracket: "]" ;
 lparen: "(" ;
 rparen: ")" ;
 bareword: ASCII_CHAR, { DIGIT | VISIBLE_CHAR | "_" }  ;
-let_keyword: "let" [WS] ;
-import_keyword: "import" [WS];
-as_keyword: "as" [WS];
+let_keyword: "let" ;
+import_keyword: "import" ;
+include_keyword: "include" ; 
+as_keyword: "as" ;
 macro_keyword: "macro" ;
 module_keyword: "module" ;
 mod_keyword: "mod" ;
@@ -134,6 +135,12 @@ call_expression: bareword, lparen, [arglist], rparen ;
 format_expr: str, percent, lparen, [arglist], rparen ;
 ```
 
+#### Include Expression
+
+```
+include_expr: include_keyword, bareword, str ; 
+```
+
 #### Non Operator Expression
 
 ```
@@ -142,6 +149,7 @@ non_operator_expr: literal
                    | macrodef
                    | module_def
                    | format_expression
+                   | include_expression
                    | copy_expression
                    | call_expression ;
 ```

integration_tests/include_example.sh

@@ -0,0 +1,2 @@
+#!/usr/bin/env bash
+echo "included"

integration_tests/include_test.ucg

@@ -0,0 +1,5 @@
+let script = include str "./include_example.sh";
+assert |
+    script == "#!/usr/bin/env bash
+echo \"included\"";
+|;

src/ast/mod.rs

@@ -457,15 +457,10 @@ impl MacroDef {
                         let mut syms_set = self.validate_value_symbols(&mut stack, val);
                         bad_symbols.extend(syms_set.drain());
                     }
-                    &Expression::Macro(_) => {
-                        // noop
-                        continue;
-                    }
-                    &Expression::Module(_) => {
-                        // noop
-                        continue;
-                    }
-                    &Expression::ListOp(_) => {
+                    &Expression::Macro(_)
+                    | &Expression::Module(_)
+                    | &Expression::ListOp(_)
+                    | &Expression::Include(_) => {
                         // noop
                         continue;
                     }
@@ -551,6 +546,14 @@ pub struct FormatDef {
     pub pos: Position,
 }
 
+/// Encodes an import statement in the UCG AST.
+#[derive(Debug, PartialEq, Clone)]
+pub struct IncludeDef {
+    pub pos: Position,
+    pub path: Token,
+    pub typ: Token,
+}
+
 /// Encodes a list expression in the UCG AST.
 #[derive(Debug, PartialEq, Clone)]
 pub struct ListDef {
@@ -625,6 +628,7 @@ pub enum Expression {
     // TODO(jwall): This should really store it's position :-(
     Grouped(Box<Expression>),
     Format(FormatDef),
+    Include(IncludeDef),
     Call(CallDef),
     Macro(MacroDef),
     Select(SelectDef),
@@ -646,6 +650,7 @@ impl Expression {
             &Expression::Module(ref def) => &def.pos,
             &Expression::Select(ref def) => &def.pos,
             &Expression::ListOp(ref def) => &def.pos,
+            &Expression::Include(ref def) => &def.pos,
         }
     }
 }
@@ -683,6 +688,9 @@ impl fmt::Display for Expression {
             &Expression::Select(_) => {
                 write!(w, "<Select>")?;
             }
+            &Expression::Include(_) => {
+                write!(w, "<Include>")?;
+            }
         }
         Ok(())
     }

src/build/mod.rs

@@ -334,6 +334,33 @@ impl<'a> FileBuilder<'a> {
             .is_some()
     }
 
+    fn find_file<P: Into<PathBuf>>(
+        &mut self,
+        path: P,
+        use_import_path: bool,
+    ) -> Result<PathBuf, Box<Error>> {
+        // Try a relative path first.
+        let path = path.into();
+        let mut normalized = self.file.parent().unwrap().to_path_buf();
+        if path.is_relative() {
+            normalized.push(&path);
+            // First see if the normalized file exists or not.
+            if !normalized.exists() && use_import_path {
+                // If it does not then look for it in the list of import_paths
+                for mut p in self.import_path.iter().cloned() {
+                    p.push(&path);
+                    if p.exists() {
+                        normalized = p;
+                        break;
+                    }
+                }
+            }
+        } else {
+            normalized = path;
+        }
+        Ok(normalized.canonicalize()?)
+    }
+
     fn eval_import(&mut self, def: &ImportDef) -> Result<Rc<Val>, Box<Error>> {
         let sym = &def.name;
         if Self::check_reserved_word(&sym.fragment) {
@@ -347,25 +374,7 @@ impl<'a> FileBuilder<'a> {
             )));
         }
         // Try a relative path first.
-        let mut normalized = self.file.parent().unwrap().to_path_buf();
-        let import_path = PathBuf::from(&def.path.fragment);
-        if import_path.is_relative() {
-            normalized.push(&import_path);
-            // First see if the normalized file exists or not.
-            if !normalized.exists() {
-                // If it does not then look for it in the list of import_paths
-                for mut p in self.import_path.iter().cloned() {
-                    p.push(&import_path);
-                    if p.exists() {
-                        normalized = p;
-                        break;
-                    }
-                }
-            }
-        } else {
-            normalized = import_path;
-        }
-        normalized = normalized.canonicalize()?;
+        let normalized = self.find_file(&def.path.fragment, true)?;
         if self.detect_import_cycle(normalized.to_string_lossy().as_ref()) {
             return Err(Box::new(error::BuildError::new(
                 format!(
@@ -1167,6 +1176,42 @@ impl<'a> FileBuilder<'a> {
         Ok(ok)
     }
 
+    pub fn eval_include(&mut self, def: &IncludeDef) -> Result<Rc<Val>, Box<Error>> {
+        return if def.typ.fragment == "str" {
+            let normalized = match self.find_file(&def.path.fragment, false) {
+                Ok(p) => p,
+                Err(e) => {
+                    return Err(Box::new(error::BuildError::new(
+                        format!("Error finding file {} {}", def.path.fragment, e),
+                        error::ErrorType::TypeFail,
+                        def.typ.pos.clone(),
+                    )))
+                }
+            };
+            let mut f = match File::open(&normalized) {
+                Ok(f) => f,
+                Err(e) => {
+                    return Err(Box::new(error::BuildError::new(
+                        format!("Error opening file {} {}", normalized.to_string_lossy(), e),
+                        error::ErrorType::TypeFail,
+                        def.typ.pos.clone(),
+                    )))
+                }
+            };
+            let mut contents = String::new();
+            f.read_to_string(&mut contents)?;
+            Ok(Rc::new(Val::Str(contents)))
+        } else {
+            // TODO(jwall): Run the conversion on the contents of the file and return it as
+            //               an Rc<Val>.
+            Err(Box::new(error::BuildError::new(
+                format!("Unknown include conversion type {}", def.typ.fragment),
+                error::ErrorType::Unsupported,
+                def.typ.pos.clone(),
+            )))
+        };
+    }
+
     // Evals a single Expression in the context of a running Builder.
     // It does not mutate the builders collected state at all.
     pub fn eval_expr(&mut self, expr: &Expression, scope: &Scope) -> Result<Rc<Val>, Box<Error>> {
@@ -1181,6 +1226,7 @@ impl<'a> FileBuilder<'a> {
             &Expression::Module(ref def) => self.eval_module_def(def, scope),
             &Expression::Select(ref def) => self.eval_select(def, scope),
             &Expression::ListOp(ref def) => self.eval_list_op(def, scope),
+            &Expression::Include(ref def) => self.eval_include(def),
         }
     }
 }

src/parse/mod.rs

@@ -509,6 +509,21 @@ make_fn!(
     )
 );
 
+make_fn!(
+    include_expression<SliceIter<Token>, Expression>,
+    do_each!(
+        pos => pos,
+        _ => word!("include"),
+        typ => match_type!(BAREWORD),
+        path => match_type!(STR),
+        (Expression::Include(IncludeDef{
+            pos: pos,
+            typ: typ,
+            path: path,
+        }))
+    )
+);
+
 fn tuple_to_call<'a>(
     input: SliceIter<'a, Token>,
     val: Value,
@@ -622,6 +637,7 @@ make_fn!(
         trace_parse!(module_expression),
         trace_parse!(select_expression),
         trace_parse!(grouped_expression),
+        trace_parse!(include_expression),
         trace_parse!(unprefixed_expression)
     )
 );

src/tokenizer/mod.rs

@@ -284,6 +284,10 @@ make_fn!(importtok<OffsetStrIter, Token>,
        do_text_token_tok!(TokenType::BAREWORD, "import", WS)
 );
 
+make_fn!(includetok<OffsetStrIter, Token>,
+       do_text_token_tok!(TokenType::BAREWORD, "include", WS)
+);
+
 make_fn!(asserttok<OffsetStrIter, Token>,
        do_text_token_tok!(TokenType::BAREWORD, "assert", WS)
 );
@@ -397,6 +401,7 @@ fn token<'a>(input: OffsetStrIter<'a>) -> Result<OffsetStrIter<'a>, Token> {
         macrotok,
         moduletok,
         importtok,
+        includetok,
         astok,
         maptok,
         filtertok,