Merge pull request #99 from nushell/source_command

Source command

crates/nu-cli/src/syntax_highlight.rs

@@ -34,7 +34,6 @@ impl Highlighter for NuHighlighter {
                     .to_string();
                 output.push((Style::new(), gap));
             }
-
             let next_token = line
                 [(shape.0.start - global_span_offset)..(shape.0.end - global_span_offset)]
                 .to_string();

crates/nu-command/Cargo.toml

@@ -16,4 +16,4 @@ nu-table = { path = "../nu-table" }
 glob = "0.3.0"
 thiserror = "1.0.29"
 sysinfo = "0.20.4"
-chrono = { version="0.4.19", features=["serde"] }
+chrono = { version="0.4.19", features=["serde"] }

crates/nu-command/src/core_commands/mod.rs

@@ -7,6 +7,7 @@ mod hide;
 mod if_;
 mod let_;
 mod module;
+mod source;
 mod use_;
 
 pub use alias::Alias;
@@ -18,4 +19,5 @@ pub use hide::Hide;
 pub use if_::If;
 pub use let_::Let;
 pub use module::Module;
+pub use source::Source;
 pub use use_::Use;

crates/nu-command/src/core_commands/source.rs

@@ -0,0 +1,43 @@
+use nu_engine::{eval_block, CallExt};
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EvaluationContext};
+use nu_protocol::{ShellError, Signature, SyntaxShape, Value};
+
+/// Source a file for environment variables.
+pub struct Source;
+
+impl Command for Source {
+    fn name(&self) -> &str {
+        "source"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("source").required(
+            "filename",
+            SyntaxShape::Filepath,
+            "the filepath to the script file to source",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Runs a script file in the current context."
+    }
+
+    fn run(
+        &self,
+        context: &EvaluationContext,
+        call: &Call,
+        input: Value,
+    ) -> Result<Value, ShellError> {
+        // Note: this hidden positional is the block_id that corresponded to the 0th position
+        // it is put here by the parser
+        let block_id: i64 = call.req(context, 1)?;
+
+        let block = context
+            .engine_state
+            .borrow()
+            .get_block(block_id as usize)
+            .clone();
+        eval_block(context, &block, input)
+    }
+}

crates/nu-command/src/default_context.rs

@@ -50,6 +50,8 @@ pub fn create_default_context() -> Rc<RefCell<EngineState>> {
         working_set.add_decl(Box::new(Git));
         working_set.add_decl(Box::new(GitCheckout));
 
+        working_set.add_decl(Box::new(Source));
+
         let sig = Signature::build("exit");
         working_set.add_decl(sig.predeclare());
         let sig = Signature::build("vars");

crates/nu-parser/src/parse_keywords.rs

@@ -3,12 +3,13 @@ use nu_protocol::{
     engine::StateWorkingSet,
     span, DeclId, Span, SyntaxShape, Type,
 };
+use std::path::Path;
 
 use crate::{
     lex, lite_parse,
     parser::{
-        check_name, garbage, garbage_statement, parse_block_expression, parse_import_pattern,
-        parse_internal_call, parse_signature, parse_string,
+        check_name, garbage, garbage_statement, parse, parse_block_expression,
+        parse_import_pattern, parse_internal_call, parse_signature, parse_string,
     },
     ParseError,
 };
@@ -765,3 +766,95 @@ pub fn parse_let(
         )),
     )
 }
+
+pub fn parse_source(
+    working_set: &mut StateWorkingSet,
+    spans: &[Span],
+) -> (Statement, Option<ParseError>) {
+    let name = working_set.get_span_contents(spans[0]);
+
+    if name == b"source" {
+        if let Some(decl_id) = working_set.find_decl(b"source") {
+            // Is this the right call to be using here?
+            // Some of the others (`parse_let`) use it, some of them (`parse_hide`) don't.
+            let (call, call_span, err) =
+                parse_internal_call(working_set, spans[0], &spans[1..], decl_id);
+
+            // Command and one file name
+            if spans.len() >= 2 {
+                let name_expr = working_set.get_span_contents(spans[1]);
+                if let Ok(filename) = String::from_utf8(name_expr.to_vec()) {
+                    let source_file = Path::new(&filename);
+
+                    let path = source_file;
+                    let contents = std::fs::read(path);
+
+                    if let Ok(contents) = contents {
+                        // This will load the defs from the file into the
+                        // working set, if it was a successful parse.
+                        let (block, err) = parse(
+                            working_set,
+                            path.file_name().and_then(|x| x.to_str()),
+                            &contents,
+                            false,
+                        );
+
+                        if err.is_some() {
+                            // Unsuccessful parse of file
+                            return (
+                                Statement::Pipeline(Pipeline::from_vec(vec![Expression {
+                                    expr: Expr::Call(call),
+                                    span: span(&spans[1..]),
+                                    ty: Type::Unknown,
+                                    custom_completion: None,
+                                }])),
+                                // Return the file parse error
+                                err,
+                            );
+                        } else {
+                            // Save the block into the working set
+                            let block_id = working_set.add_block(block);
+
+                            let mut call_with_block = call;
+
+                            // Adding this expression to the positional creates a syntax highlighting error
+                            // after writing `source example.nu`
+                            call_with_block.positional.push(Expression {
+                                expr: Expr::Int(block_id as i64),
+                                span: spans[1],
+                                ty: Type::Unknown,
+                                custom_completion: None,
+                            });
+
+                            return (
+                                Statement::Pipeline(Pipeline::from_vec(vec![Expression {
+                                    expr: Expr::Call(call_with_block),
+                                    span: call_span,
+                                    ty: Type::Unknown,
+                                    custom_completion: None,
+                                }])),
+                                None,
+                            );
+                        }
+                    }
+                }
+            }
+            return (
+                Statement::Pipeline(Pipeline::from_vec(vec![Expression {
+                    expr: Expr::Call(call),
+                    span: call_span,
+                    ty: Type::Unknown,
+                    custom_completion: None,
+                }])),
+                err,
+            );
+        }
+    }
+    (
+        garbage_statement(spans),
+        Some(ParseError::UnknownState(
+            "internal error: source statement unparseable".into(),
+            span(spans),
+        )),
+    )
+}

crates/nu-parser/src/parser.rs

@@ -1,5 +1,6 @@
 use crate::{
     lex, lite_parse,
+    parse_keywords::parse_source,
     type_check::{math_result_type, type_compatible},
     LiteBlock, ParseError, Token, TokenContents,
 };
@@ -2870,6 +2871,7 @@ pub fn parse_statement(
         b"alias" => parse_alias(working_set, spans),
         b"module" => parse_module(working_set, spans),
         b"use" => parse_use(working_set, spans),
+        b"source" => parse_source(working_set, spans),
         b"export" => (
             garbage_statement(spans),
             Some(ParseError::UnexpectedKeyword("export".into(), spans[0])),

crates/nu-protocol/src/value/mod.rs

@@ -247,6 +247,7 @@ impl Value {
         }
     }
 
+    /// Follow a given column path into the value: for example accessing nth elements in a stream or list
     pub fn follow_cell_path(self, cell_path: &[PathMember]) -> Result<Value, ShellError> {
         let mut current = self;
         for member in cell_path {

crates/nu-protocol/src/value/range.rs

@@ -1,6 +1,7 @@
 use serde::{Deserialize, Serialize};
 use std::cmp::Ordering;
 
+/// A Range is an iterator over integers.
 use crate::{
     ast::{RangeInclusion, RangeOperator},
     *,